Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The preservation of high-moisture barley and the nutritional evaluation with monogastrics and ruminants Pringle, Dave Bruce 1982

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Notice for Google Chrome users:
If you are having trouble viewing or searching the PDF with Google Chrome, please download it here instead.

Item Metadata

Download

Media
831-UBC_1982_A6_7 P75.pdf [ 7.23MB ]
Metadata
JSON: 831-1.0095427.json
JSON-LD: 831-1.0095427-ld.json
RDF/XML (Pretty): 831-1.0095427-rdf.xml
RDF/JSON: 831-1.0095427-rdf.json
Turtle: 831-1.0095427-turtle.txt
N-Triples: 831-1.0095427-rdf-ntriples.txt
Original Record: 831-1.0095427-source.json
Full Text
831-1.0095427-fulltext.txt
Citation
831-1.0095427.ris

Full Text

THE PRESERVATION OF HIGH-MOISTURE BARLEY AND THE NUTRITIONAL EVALUATION WITH MONOGASTR1CS AND RUMINANTS by DAVE BRUCE PRINGLE B.Sc. (Agric) The University of B r i t i s h Columbia, 1980 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department of Animal Science) We accept t h i s t hesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA October 1982 0 Dave Bruce P r i n g l e , 1982 In presenting t h i s thesis in p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, 1 agree that the Library s h a l l make i t f r e e l y a v a i l a b l e for reference and study. I further agree that permission for extensive copying of t h i s t h e s i s for s c h o l a r l y purposes may be granted by the Head of my Department or by his representatives. It i s understood that copying or p u b l i c a t i o n of t h i s t h e s i s for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of Animal Science The U n i v e r s i t y of B r i t i s h Columbia 2075 Wesbrook Place Vancouver, Canada V6T 1W5 ABSTRACT High-moisture barley, preserved either anaerobically, chemically or by drying, was evaluated in a series of d i g e s t i b i l i t y and nitrogen u t i l i z a t i o n t r i a l s with monogastrics and ruminants. In the f i r s t of 3 phases, high-moisture barley HMB (17% moisture) from the Peace River region was preserved in experimental s i l o s by: (1) a i r t i g h t storage, (2) a l k a l i - 3.2 g NaOH/kg HMB ( a i r dry basis) in a 32% w/w solution, (3) acid - 1% mixture of 60:40 acetic-propionic acids and (4) drying - 8 tonnes per hour at 82°C. After 9 months of storage, these treatments were evaluated in a d i g e s t i b i l i t y t r i a l with pigs and a nitrogen balance t r i a l with r a t s . In the pigs there was no treatment e f f e c t on dry matter d i g e s t i b i l i t y , but neutral detergent f i b r e d i g e s t i -b i l i t y was reduced (P < 0.001) in the dried barley. True nitrogen d i g e s t i b i l i t y , with both pigs and rats, was s i g n i f i c a n t l y (P < 0.001) reduced by a l k a l i treatment. In the rat t r i a l , a l k a l i - t r e a t e d barley depressed net protein u t i l i z a t i o n (NPU) by over 20%. Differences between the non-alkali treatments were small. D i g e s t i b i l i t y studies with sheep were not ca r r i e d out on these treatments due to poor p a l a t a b i l i t y r e s u l t s . In the second phase, barley from Lacombe was harvested at 33 and 12% moisture. The HMB (33% moisture) was either stored a i r t i g h t or a r t i f i c i a l l y dried (ADB) to 88% DM and the f i e l d - d r i e d barley (FDB) (12% moisture) was either stored a e r o b i c a l l y or reconstituted (RB) to 70% DM and stored a i r t i g h t . These treatments were evaluated in a nitrogen balance t r i a l with rats and a d i g e s t i b i l i t y , nitrogen-retention t r i a l with sheep. In the rat t r i a l , true nitrogen d i g e s t i b i l i t y was highest i i i -(P < 0.001) for HMB while b i o l o g i c a l valve was higher (P < 0.001) for both of the dry treatments. NPL) tended to be the same for a l l treatments. In the sheep t r i a l , dry matter d i g e s t i b i l i t y of RB was improved above ADB, but organic matter d i g e s t i b i l i t y of both HMB and RB were greater than that of ADB (P < 0.01). Acid detergent f i b r e d i g e s t i b i l i t y of HMB was highest (P < 0.001) followed by FDB and RB and then ADB. There was no treatment e f f e c t for either nitrogen d i g e s t i b i l i t y or nitrogen retention. Straw from both HMB and FDB was also evaluated in sheep. Apparent dry matter, organic matter and nitrogen d i g e s t i b i l i t y were a l l s i g n i f i c a n t l y (P < 0.001) greater for straw from HMB. The f i n a l phase of the study was conducted with barley of an unknown o r i g i n . Dry barley was reconstituted to 30% moisture (RB) and portions were treated with 3% NaOH (NaOH-RB) or 1% and 3% anhydrous ammonia ( N H 3-RB) on a w/w a i r dry basis. These treatments were again evaluated in a nitrogen balance t r i a l with rats and a d i g e s t i b i l i t y , nitrogen-retention t r i a l with sheep. In the rat t r i a l , true nitrogen d i g e s t i b i l i t y for NaOH-RB was approximately 20% lower than the other treatments. B i o l o g i c a l value and NPU were also depressed below a l l other treatments by NaOH-RB (P < 0.001). NPU for both 1 and 3% N H 3-RB were lower (P < 0.001) than RB after most of the N H 3 was allowed to evaporate for several days. However, there appeared to be no residual e f f e c t on protein u t i l i z a t i o n after the NH3 was removed completely from the treated barley, as NPU for both 1 and 3% NH3-RB were not d i f f e r e n t from RB. Dry matter d i g e s t i b i l i t y was improved by a l l alkali-treatments (P < 0.001). In the sheep t r i a l , both apparent dry matter d i g e s t i b i l i t y and organic matter d i g e s t i b i l i t y were - iv -s i g n i f i c a n t l y (P < 0.01) better f or only the 3% NH3-RB as compared to the other treatments. Acid detergent f i b r e d i g e s t i b i l i t y was lower for 1 and 3% NH3-RB than RB or NaOH-RB, between which treatments there were no s i g n i f i c a n t d i f f e r e n c e s . NaOH treatment reduced nitrogen d i g e s t i b i l i t y by approximately 20 percentage u n i t s , but nitrogen-retention was unchanged between treatments with sheep. - V -TABLE OF CONTENTS Page ABSTRACT i i TABLE OF CONTENTS v LIST OF TABLES v i i i LIST OF FIGURES x ACKNOWLEDGMENTS x i INTRODUCTION 1 LITERATURE REVIEW 4 1. Introduction 4 2. Harvesting High-Moisture Barley 4 2.1 Maturity 4 2.2 T h r e s h a b i l i t y 5 2.3 Yield..... 5 3. Factors Affecting S t o r a b i l i t y of Grain 8 3.1 Moisture and Temperature 9 3.2 Microorganisms i n Grain 11 3.2.1 F i e l d Fungi 13 3.2.2 Storage Fungi 13 3.2.2.1 Mycotoxins 15 3.2.2.2 Spontaneous Heating 16 4-. Storage Methods and Treatments 16 4.1 A i r t i g h t Storage/Controlled Atmosphere 17 4. 1.1 P r i n c i p l e s of A i r t i g h t Storage 18 4. 1.2 Storage F a c i l i t i e s 20 4.1.3 Changes During A i r t i g h t Storage 24 4.1.4 N u t r i t i o n a l Values 26 4.2 Refrigerated Storage 30 4-.2.1 P r i n c i p l e s of Refrigerated Storage 30 4.2.2 Storage F a c i l i t i e s 32 4.2.3 Changes During Refrigerated Storage 33 4.3 Chemical Preservation 34 4.3.1 Acid Treatments 35 4.3.1.1 P r i n c i p l e s of Acid Treatments 35 4.3.1.2 Acids and N u t r i t i o n a l Values 36 4.3.1.2.1 Formic Acid and Formaldehyde 36 4.3.1.2.2 Acetic and Propionic Acids 38 4.3.1.2.3 Summary 43 - v i -Page. 4.3.2 A l k a l i Treatments 43 4.3.2.1 P r i n c i p l e s of A l k a l i Treatments... 43 4.3.2.2 A l k a l i s and N u t r i t i o n a l Values.... 46 4.3.2.2.1 Sodium Chloride and Urea 46 4.3.2.2.2 Sodium Hydroxide 47 4.3.2.2.3 Ammonia 50 4.3.2.2.4 Summary 54 4.3.2.3 Chemical Aspects of A l k a l i -Treated Grain 55 4.3.2.4 Experimental A p p l i c a t i o n and S t o r a b i l i t y of Ammoniated Grain.. 58 4.3.3 Treating and Storing Chemically Preserved Grain 62 MATERIALS AND METHODS 65 1 . I n t roduc t ion 65 2. Phase I 65 2.1 I n i t i a l Experiments 67 2.2 Experiment 1: D i g e s t i b i l i t y T r i a l with Pigs Fed Barley from Peace River 68 2.3 Experiment 2: Nitrogen Balance T r i a l with Rats Fed Barley from Peace River , 70 3. Phase II 72 3.1 Experiment 1: D i g e s t i b i l i t y T r i a l with Sheep Fed Barley-Straw from Lacombe 74 3.2 Experiment 2: D i g e s t i b i l i t y and Nitrogen-Retention T r i a l with Sheep Fed Barley-Grain from Lacombe 75 3.3 Experiment 3: Nitrogen Balance T r i a l with Rats Fed Barley from Lacombe 77 Phase III 78 4.1 Experiment 1: D i g e s t i b i l i t y and Nitrogen-Retention T r i a l with Sheep Fed Reconstituted, A l k a l i Treated Barley 81 4.2 Experiment 2: Nitrogen Balance T r i a l with Rats Fed Reconstituted, A l k a l i - T r e a t e d Barley 83 4.3 Experiment 3: NH3~Retention of Reconstituted, Ammoniated Barley 84 5 . Chemical Analyses 85 5.1 Nitrogen 85 5.2 Moisture 85 5.3 Acid and Neutral Detergent Fibre 86 5.4 Ash 86 6. S t a t i s t i c a l A n a l y s i s 86 - v i i -Page RESULTS AND DISCUSSION 87 1. Phase I 87 1.1 Core Temperatures of Barley from Peace River 87 1.2 Experiment 1: Digestibility Trial with Pigs with Barley from Peace River 90 1.3 Experiment 2: Nitrogen Balance Trial with Rats with Barley from Peace River - 90 2. Phase II 97 2.1 Experiment 1: Digestibility Trial with Sheep Fed Barley-Straw from Lacombe 97 2.2 Experiment 2: Digestibility and Nitrogen-Retention Trial with Sheep Fed Whole Barley-Grain from Lacombe 99 2.3 Experiment 3: Nitrogen Balance Trial with Rats Fed Barley from Lacombe 105 3. Phase III 109 3.1 Experiment 1: Digestibility and Nitrogen-Retention Trial with Sheep Fed Reconstituted, Alkali-Treated, Whole Barley 109 3.2 Experiment 2: Nitrogen Balance Trial with Rats Fed Alkali-Treated Barley 117 3.3 Experiment 3: NH3-Retention of Reconstituted, Ammoniated Barley 120 SUMMARY AND CONCLUSIONS 125 BIBLIOGRAPHY 129 - v i i i -LIST OF TABLES Page Table 1 V a r i e t a l d i f f e r e n c e s in y i e l d when cut at high-moisture and mature stages 6 Table 2 Safe anaerobic storage periods of several c e r e a l grains at d i f f e r e n t temperature and moisture contents 10 Table 3 Some biochemical changes in wheat af t e r 7 months of hermetic storage 25 Table 4 Estimated maximum number of weeks of mould-free storage of barley at various temperatures and moisture contents 32 Table 5 A p p l i c a t i o n rates of propionic acid for high-moisture grain 39 Table 6 A p p l i c a t i o n rates of a c e t i c - p r o p i o n i c acid f or high-moisture grain as recommended by manufacturers of Chemstor 40 Table 7 Vitamins and minerals added to barley at a l e v e l of 3 g/100 g f i n a l d i e t (DM basis) for pigs in t r i a l PI-E1 69 Table 8 Composition of mixtures added to d i e t s for r a t s i n t r i a l s PI-E2, PII-E3 and PIII-E2 71 Table 9 Botanical composition of barley from Lacombe (Phase II) 73 Table 10 Trace mineralized s a l t with selenium supplement for sheep in t r i a l s PII-E1, E2 and PIII-E1 75 Table 11 D i g e s t i b i l i t y of r o l l e d and whole high-moisture barley preserved in four d i f f e r e n t ways from Peace River determined with pigs in PI-E1 90 Table 12 Dry matter d i g e s t i b i l i t y and protein u t l i z a t i o n c o e f f i c i e n t s of high-moisture barley stored in four d i f f e r e n t ways from Peace River determined with rats in PI-E2 91 Table 13 Chemical composition of high-moisture barley from Peace River preserved in four d i f f e r e n t ways for Phase 1 92 - ix -Page Table 14- Chemical composition, voluntary intake and d i g e s t i b i l i t y of barley-straw from high-moisture and f i e l d dried barley from Lacombe, fed to sheep in PII-E1 98 Table 15 Chemical composition of barley harvested and preserved i n various ways from Lacombe for Phase II ; 100 Table 16 Nitrogen-retention and d i g e s t i b i l i t y of whole barley-grain preserved i n four d i f f e r e n t ways from Lacombe determined with sheep in t r i a l PII-E2 101 Table 17 Dry matter d i g e s t i b i l i t y and protein u t i l i z a t i o n c o e f f i c i e n t s of barley harvested and preserved i n various ways from Lacombe determined with rats in PII-E3 106 Table 18 Nitrogen-retention and d i g e s t i b i l i t y f o r re c o n s t i t u t e d , a l k a l i - t r e a t e d , whole barley determined with sheep in t r i a l PIII-E1 109 Table 19 Chemical composition of reconstituted, a l k a l i -treated barley for Phase III 112 Table 20 Actual d a i l y mean nitrogen contents of feed, feces and urine for sheep fed reconstitued, a l k a l i -treated barley in t r i a l PIII-E1 115 Table 21 Dry matter d i g e s t i b i l t y and protein u t i l i z a t i o n c o e f f i c i e n t s of a l k a l i - t r e a t e d barley determined with rats in PIII-E2 117 Table 22 Time of NH3 a p p l i c a t i o n and NH3-retention (nitrogen %) of sealed then aerated, ammoniated barley in PIII-E3 121 - X -LIST OF FIGURES Page Figure 1 I n d i r e c t r e l a t i o n s h i p s between p h y s i o l o g i c a l maturity and y i e l d of barley 7 Figure 2 Changes in core temperature of grain bins with time in Phase 1 88 Figure 3 Changes i n nitrogen percent of barley reconstituted at varying l e v e l s , treated with NH3 and aerated over time at room temperature in PI1I-E3 122 Figure 4 Changes i n moisture content of barley reconstituted at varying l e v e l s , treated with NH3 and aerated over time at room temperature in PIII-E3 123 ACKNOWLEDGEMENTS I wish to express my deep respect for Dr. B.D. Owen, Chairman of the Department of Animal Science, who encouraged me to pursue this work and continue with my formal education. The advice, guidance and assistance from my supervisor, Dr. R.M. Beames of the Department of Animal Science, was greatly appreciated and is at this time sincerely acknowledged. Gratitude is also extended to Dr. R.M. Tait also of the Department of Animal Science, who made valuable contributions to both the design and execution of this study. The technical assistance from Mrs. 3. Litsky and advice from Mr. E.B. Cathcart were greatly appreciated throughout this study. Thanks must also be given to the staff of the campus farm for their cooperation. Finally, I would like to acknowledge the Natural Sciences and Engineering Research Council of Canada for their financial support. INTRODUCTION In many grain producing regions of the world, i t i s often necessary to harvest grain before i t has f i e l d - d r i e d , due to inclement weather conditions. By harvesting high-moisture barley, dry matter y i e l d may increase by 10 to 20% ( K r a l l 1972; Mederick et a l . 1982) and the r i s k of f i e l d losses i s greatly reduced. However, t h i s moist grain must be either dried, stored hermetically or chemically preserved to prevent storage losses as a result of invading microorganisms. With the i n f l a t i o n a r y costs of energy, drying i s quickly becoming too expensive and time consuming, e s p e c i a l l y for large quantities of moist grain. Consequently, alternate methods of preservation have been introduced in recent years. Although successful a i r t i g h t storage of high-moisture grain has been documented for centuries, i t s potential as a viable a l t e r n a t i v e to drying has not yet been f u l l y r e a l i z e d . However, storing grain hermetically i s gaining in popularity among producers, who either feed the grain on the farm or have a l o c a l market to supply ( i . e . feedlots, d a i r i e s , e t c . ) . More recently, in approximately the past 14- years, organic acids (propionic and acetic) have been used successfully in preserving high-moisture grain, without deleterious e f f e c t s on n u t r i t i o n a l quality for either ruminants or monogastrics. Grain preserved with acid can be stored a e r o b i c a l l y , but the a v a i l a b l i l t y and corrosive nature of the acid hampered i t s popularity with potential high-moisture grain producers. Even more recently, since 1977, a l k a l i preservatives have been studied. I n i t i a l l y , sodium hydroxide (NaOH) was incorporated as a grain - 2 -processing agent and was, subsequently, found to have preserving q u a l i t i e s too. The documented work to date on NaOH-treated grain has been conducted with ruminants only, without mention of nitrogen u t i l i z a t i o n . It was surmised that the protein quality of NaOH-treated grain would be s i g n i f i c a n t l y reduced for, at l e a s t , monagastric animals, due to the severe a l k a l i n i t y imposed on the grain promoting racemization of amino acids (Hayashi and Kameda 1980), formation of synthetic amino acids (Friedman 1969) and binding of amino acids and reducing sugars (browning or Maillard reaction) (Hayashi and Naniki 1981). Following NaOH was ammonia ( N H 3 ) , t h i s chemical was reported as having preserving q u a l i t i e s and a n u t r i t i o n a l benefit, regarding nitrogen u t i l i z a t i o n in ruminants. Again, work with monogastrics has not been documented. Also, the v o l a t i l e nature of NH3 lessens i t s employment as a preservative, as free NH3 i s invariably l o s t during nonhermetic storage. This study was conducted in three phases with each phase c o n s i s t i n g of 2 or 3 experiments. The objective of the f i r s t phase was to compare and evaluate dry matter d i g e s t i b i l i t y and protein u t i l i z a t i o n of high-moisture grain which had been either dried, stored a i r t i g h t or preserved with organic acid or sodium hydroxide, in pigs and r a t s . Grain temperature during storage was also monitored. In the second phase, the objectives were to evalute the d i g e s t i b i l i t y of barley-straw from both high-moisture grain and f i e l d - d r i e d grain in sheep and barley-grain which had been harvested as high-moisture or f i e l d - d r i e d barley and preserved as high-moisture or a r t i f i c i a l l y dried barley and f i e l d - d r i e d or reconstituted barley. These four barley - 3 -treatments were given to sheep and r a t s i n order to determine dry matter d i g e s t i b i l i t y , nitrogen u t i l i z a t i o n , organic matter and a c i d detergent f i b r e d i g e s t i b i l i t y , the l a t t e r two were measured i n sheep only. The f i n a l phase was conducted with reconstitued barley treated with NaOH and 1 or 3% NH3. The o b j e c t i v e of t h i s phase was to compare the n u t r i t i o n a l c o e f f i c i e n t s , as described e a r l i e r i n the second phase, of barley which had been e i t h e r r e c o n s t i t u t e d and then a l k a l i - t r e a t e d or r e c o n s t i t u t e d and stored a i r t i g h t , i n both sheep and r a t s . Some measurements r e l a t i n g to the N ^ - r e t e n t i o n by the barley were also taken. - 4 -LITERATURE REVIEW 1. Introduction The purpose of t h i s l i t e r a t u r e review i s to present supporting knowledge for t h i s t h e s i s , and ultimately to validate the course of study pursued. The following summary of the l i t e r a t u r e w i l l highlight published r e s u l t s concerning harvesting, storing, preserving and feeding of high-moisture grain, p r i n c i p a l l y barley. 2. Harvesting High-Moisture Barley 2.I Maturity The idea of harvesting barley early i s not new. In 1912, Brenchley reported no change in dry matter y i e l d of barley for 3 weeks prior to conventional harvesting. Harlan (1920) found no t r a n s - l o c a t i o n of plant materials in barley after the moisture content lowered to 42%, thereafter the kernel dried at a rate of 2% per day and dry matter y i e l d remained constant. However, Koenig et a l . (1965) found an increase in the kernel weight of barley up u n t i l the moisture l e v e l f e l l below 33%. In swathing t r i a l s , McLean (1933) and Dodds and Dew. (1958) reported no s i g n i f i c a n t reduction in either y i e l d or kernel weight of barley when swathed a week before maturity. It has been determined by K r a l l (1972) that the v a r i a t i o n in physiological maturity i s a result of v a r i e t a l d i fferences which explains the wide range in moisture content (30 to 40%) found in the l i t e r a t u r e for p h y s i o l o g i c a l l y mature barley. - 5 -2.2 Thr e s h a b i l i t y Threshability i s a major concern of many potential high-moisture barley producers. It i s b a s i c a l l y a function of variety, moisture content and combine technique. Consequently, there i s a considerable differ e n c e between v a r i e t i e s in the range of moisture contents at which threshing can be successfully achieved. K r a l l (1972) threshed barley at 30-40% moisture e a s i l y , but noted v a r i e t a l differences with the two-rowed v a r i e t i e s , Betzes and Ingrid threshing e a s i e s t . In other reports, numerous v a r i e t i e s of barley with 21.5-47.8% moisture were harvested and in no instances were d i f f i c u l i t e s encountered i n the d i r e c t combining of the high-moisture grain (Pratt et a l . 1961; K r a l l and Thomas 1964; Northwest School of Agr i c u l t u r e , U. of Minn. 1961). In B r i t a i n , barley i s routinely harvested between 16-21% moisture (Briggs 1978). Therefore, the farmer's concern of poor t h r e s h a b i l i t y with high-moisture barley may possibly be a l l e v i a t e d by proper v a r i e t a l s e l e c t i o n and by a properly adjusted combine harvester in order to maximize percent separation of tough grain from the s t a l k . 2.3 Y i e l d Due to early p h y s i o l o g i c a l maturity, i t i s possible to harvest high-moisture grain without a loss of p r o d u c t i v i t y . K r a l l (1972) reported increases in dry matter y i e l d from several locations and v a r i e t i e s , ranging from 16.9 to 1.4% for barley under i r r i g a t i o n and 17.3 to -5.9% for barley on dryland. Normally when grain i s grown under i r r i g a t i o n swathing i s practised, but when harvesting high-moisture grain d i r e c t combining i s usually s u f f i c i e n t under most conditons. This - 6 -effectively eliminates the need for swathing prior to threshing, which is most common throughout Canada, as a means to reduce the grain drying time in the field. In other trials, Krall (1972) tabulated varietal differences in yield when cut at high-moisture versus mature stages (Table 1). Mederick et al. (1982) recorded increases in dry matter yield, averaging 20%, for several barley varieties harvested at approximately 30% moisture. Yield increases of this magnitude are Table 1. Varietal difference in yield when cut at high-moisture (35% average) and mature stages. Average of 3 years and 5 locations. Variety Hi-Moisture Bu./A Mature Yield Difference Percent Increase Compana 60.6 57.2 3.4* 5.6 Betzes 63.9 57.3 6.6** 10.3 Unitan 71.2 68.9 2.3* 3.2 Nupana 58.3 51.6 6.7** 11.5 Vantage 77.1 73.2 3.9* 5.1 Ingrid 75.2 72.2 3.0* 4.0 Hypana 57.6 58.9 -1.3 -2.2 * 95% probability of a real difference **99% probability of a real difference Source: Krall (1972) totally plausible if one considers the variation in actual and potential yields in barley crops, as noted by Briggs (1978). It becomes apparent that increases in yield due to early harvest will, ultimately, be only indirectly affected by physiological maturity (moisture content). Figure 1 combines, several observations from the literature and illustrates how yield is affected by physiological maturity through these potentially limiting factors (variety, threshability and the combine harvester). Maintaining good threshability - 7 -P h y s i o l o g i c a l Maturity Variety >• T h r e s h a b i l i t y -* Combine Harvester V Y i e l d Figure 1. Indirect r e l a t i o n s h i p s between p h y s i o l o g i c a l maturity and y i e l d of barley. of high-moisture barley, y i e l d i s also increased as stated e a r l i e r . The reasons for t h i s increased p r o d u c t i v i t y may be accounted for by less shattering of dry kernels and an increase i n the percentage of thins ( t h i n kernels in high-moisture barley are heavier due to the moisture content and are consequently not blown out with the chaff during combining as i s the case with dry g r a i n ) . These findings are supported by increased f i b r e l e v e l s of 1.59% in high-moisture barley over mature barley, reported by K r a l l (1972). In summary, he also l i s t e d the advantages and disadvantages associated with harvesting high-moisture barley as follows: Advantages 1. An increase i n dry matter y i e l d , averaging 6.7% and ranging as high as 17.3% 2. Average of 12 days less chance for storm damage 3. No need to wait for green patches in the f i e l d to mature 4. Swathing on i r r i g a t e d land and in short growing season areas i s not necessary - 8 -5. Short strawed v a r i e t i e s are easier to harvest 6. Weed seeds, e s p e c i a l l y wild oats, are c o l l e c t e d before shattering 7. Post-harvest period i s lengthened allowing for better weed control with c u l t i v a t i o n or growing a second crop 8. Less chance of damage from f i e l d fungi Disadvantages 1. A slower separation of grain from the straw in the combine 2. Must haul from 20-25% more weight 3. Marketing i s a problem due to moisture content 4. Grain may not flow as readily 5. Grain must be properly stored or heating and spoilage w i l l develop The s i g n i f i c a n c e of the advantages and disadvantages presented here w i l l vary in regions where environmental conditions are more severe than others ( i . e . B.C. vs. Alberta), and again the variety grown and moisture l e v e l at harvest time w i l l ultimately have a bearing when assessing economical gains. 3. Factors Affecting Storability of Grain Properly stored grain may maintain 96% germinability for up to 32 years (Briggs 1978). However, Christensen and Kaufmann (1969) and Brooker et a l . (1974) reported that approximately 5 - 4.5%, respectvely, of the world's food grains harvested were lo s t during storage. These would be very conservative estimates in 3ames' (1980) opinion, who reported post-harvest losses to be as high as 20% and Spurgeon (1976) - 9 -reported losses over 30% in t r o p i c a l areas. Deterioration of stored grain i s primarily a function of moisture, temperature and a host of b i o l o g i c a l pests, a l l of which are d i r e c t l y effected by oxygen supply (Brooker et a l . 1974). Therefore, there are many i n t e r r e l a t i n g factors opposing the successful storage of conventional barley, which are only accentuated when storing high-moisture barley. 3.1 Moisture and Temperature Moisture and temperature are two physical variables which function together in determining storage c h a r a c t e r i s t i c s of grain. Because of t h i s strong dependency, i t i s very d i f f i c u l t to discuss these v a r i a b l e s independently without being r e p e t i t i o u s . For t h i s reason moisture and temperature w i l l be reviewed together here, and in future sections. Conventionally, under aerobic conditions, barley i s stored at moisture l e v e l s not exceeding 11 - 13% in order to prevent losses due to r e s p i r a t i o n and microbial attack for as long as 5 years (Sinha 1973, Brooker et a l . 1974). However, losses contributed to excessive moisture are a d i r e c t function of temperature and r e l a t i v e humidity (RH) (Haward et a l . 1974). Table 2 indicates the r e l a t i o n s h i p between these two conditions in a t r o p i c a l location where Hyde and Burrel (1973) reported fungal growth on barley of 13% moisture. Therefore, as temperature and RH increase grain stores become more susceptible to spoilage. Part of the storage problem in areas with high RH stems from absorption of atmospheric moisture u n t i l an equilibrium i s reached. Grain o r i g i n a l l y stored at 12% moisture could conceivably absorb an additional 4% - 10 -Table 2. Safe aerobic storage periods (weeks) of several cereal grains at d i f f e r e n t temperatures (°C) and moisture contents (%, a i r dry b a s i s ) , ( c r i t e r i o n : germinability) Type of Moisture Content Grain Temp 11 .0 12.0 13.0 14.0 15.0 16.0 17.0 19.0 23.0 Barley 20 110 80 50 32 19 10 5 2.5 0.5 15 240 170 100 65 40 20 10 4 1 10 600 400 260 160 90 50 21 8.5 2 Type of Moisture Content Grain Temp 11.0 11 .5 12.5 13.0 14.0 15.0 17.0 19.0 22.0 Oats 20 80 55 38 26 15 8 4.5 2 0.5 15 160 110 70 45 26 15 7.5 3.5 1 10 350 230 150 95 55 30 16 6 1.5 Type of Moisture Content Grain Temp 12.0 13.0 13.5 14.5 15.5 16.5 17.5 19.5 23.0 Wheat 20 55 40 28 19 13 7 3.5 1.5 0.5 15 100 75 50 30 20 12 6 3 1 10 200 140 95 60 38 20 11 4.5 1.5 Type of Moisture Content Grain Temp 11.5 12.5 13.0 14.0 15.0 16.0 18.0 20.0 24.0 Rye 20 30 23 17 13 7.5 4.5 2.5 1 .5 0.5 15 50 34 23 16 10 6.5 4 2 1 10 75 55 40 25 16 10 5.5 3 1 Source: Brooker et a l . (1974). moisture as a consequence of warm temperature and high RH. This grain could eventually become unstable and be prone to spoilage as the moisture content r i s e s ( T r i s v y a t s k i i 1969; Wallace 1973). Moisture migration i s another important phenomenon a f f e c t i n g storage due to moisture and temperature v a r i a t i o n . Muir (1973) suggested three possible mechanisms for moisture migration i n stores of grain - vapour d i f f u s i o n through intergranular a i r spaces, moisture - 11 -d i f f u s i o n through s o l i d kernel matter and moisture carried by convective a i r currents - the l a s t one appearing to be most s i g n i f i c a n t . However, Anderson et a l . (1943), Ayerst (1965) and Haward et a l . (1974) believe the rate of moisture migration through grain i s lim i t e d by the rate of transfer of moisture through intergranular a i r since t h i s transfer occurs more slowly than the exchange of moisture between a i r and grain. The reason for moisture migration i s mainly a matter of temperature gradients in and around a grain bulk, causing convective a i r currents (Muir 1973). These currents pick up moisture from the warm grain at the centre of the bin and deposit i t in the cooler grain near the surface of the bin. After three months of storage, Holman and Carter (1952) recorded a 4% increase in moisture near the surface of the grain bin than when i t was i n i t i a l l y stored, due to migration. Therefore, even grain stored at a safe moisture content could be susceptible to l o c a l i z e d spoilage. 3.2 Microorganisms i n Grain Heating, associated with moist grain, was at one time thought to be due to r e s p i r a t i o n of the grain i t s e l f . This b e l i e f was f i r s t d i s c r e d i t e d by Darsie et a l . (1914) when they demonstrated a d r a s t i c increase in heat production with fungi infected grain over non-infected moist grain. Later, Hummel et a l . (1954) stored moist wheat, free from fungi, at 35°C and found the r e s p i r a t i o n l e v e l to be non-detectable. Furthermore, seed r e s p i r a t i o n could not possibly raise the temperature above 30°C in grain moist enough to re s p i r e , since the seed would not be able to survive - and dead seeds do not respire (Christensen and - 12 -Kaufmann 1974). As a r e s u l t , microflora are primarily responsible for the heating of high-moisture grain (Christensen and Gordon 1948; Carter 1950; Christensen and Kaufmann 1974; Bothast et a l . 1975). In developing countries, fungi are probably the single most destructive agent in grain stores (Busta et a l . 1980). There i s a host of thermophilic bacteria associated with storage losses, but generally they do not become a s i g n i f i c a n t factor u n t i l the f i n a l stages of spoilage when the grain has already become u n f i t for food (Christensen and Kaufmann 1974). E a r l i e r , Christensen and Kaufmann (1969) l i s t e d the major losses caused by fungi as being: (1) decrease in germinability, (2) di s c o l o u r a t i o n and t a i n t i n g , (3) heating and mustiness, (4) biochemical change, (5) production of toxins and (6) loss of dry matter - a l l of which may take place without the fungi being apparent to the naked eye. These losses are a l l f a i r l y e x p l i c i t with the exception of number 4. Briggs (1978) summarized the biochemical changes in mouldy grains as: a. an increase in free f a t t y acids followed by a decline, b. an increase in reducing sugars and a decrease in non-reducing sugars and c. a decline in l e v e l s of vitamin E and l y s i n e and no decline in protein d i g e s t i b i l i t y ( u n t i l the grain i s stored over 18% moisture), but with a decline in b i o l o g i c a l value. Due to the s i g n i f i c a n t impact of fungi on stored grains and t h e i r complexity, they are normally c l a s s i f i e d in two e c o l o g i c a l groups -f i e l d fungi and storage fungi. These groups w i l l be discussed separately below. - 13 -3.2.1 F i e l d Fungi The major f i e l d fungi found on cereal grains belong to the genera A l t e r n a r i a , Fusarium, Cladosporium and Helminthosporium (Christensen and Kaufmann 1974), only the l a s t mentioned genus does not a f f e c t barley (Wallace 1973). F i e l d fungi attack the grain in the f i e l d before i t i s threshed and may cause discolouration and reduced germinability (Christensen and Kaufmann 1969). A l l f i e l d fungi require a high moisture content (30-33%) in order to grow (Koehler 1938). Therefore, one would expect these fungi to be a problem during the storage of high-moisture grain, but apparently any development of mould growth during the storage of damp grain r e s u l t s from storage fungi and not f i e l d fungi (Brooker et a l . 1974). Since f i e l d fungi usually invade standing grain when i t i s mature or after poor weather conditions have prevailed, harvesting high-moisture barley may help prevent losses caused by these fungi. 3.2.2 Storage Fungi The storage fungi consist primarily of only 5 or 6 species of As p e r g i l l u s , several species of Penicillum and a single species of Sporendonema (Christensen and Kaufmann 1974). The conditions that govern the development of these fungi are: (1) moisture content of the stored grain, (2) temperature, (3) a c t i v i t y of insects and mites, (4) oxygen supply, (5) length of storage time, (6) extent of invasion p r i o r to storage and (7) amount of foreign material in the grain (Christensen and Kaufmann 1969; Hyde and Burrel 1973). It i s apparent that these fungi can thriv e under a very diverse environment, however, r e s t r i c t i n g - 14 -any one or combinations of the above factors can have s i g n i f i c a n t advantages in supressing mould growth. The minimum moisture content, for storage fungi development, varies in grains but i s generally about 14% with a RH of 70-90% (Muir 1973). Under these conditions, temperatures may vary between -8°C (A.  glaucus) to 58°C (A. fumigatus) and favour mould growth. The widest range of fungi grow best at temperatures between 30 - 32°C (Semeniuk 1954). The a c t i v i t y of insects and mites tends to increase the moisture content of the grain and also i n f e c t the grain with spores of fungi (Christensen and Kaufmann 1969). Their a c t i v i t y can be r e l a t i v e l y e a s i l y c ontrolled by the use of i n s e c t i c i d e s or fumigants (Briggs 1978), modifying atmospheric gas concentrations (Navarro and Calderon 1980), heating grain at 60°C for 15 minutes to k i l l invaded insects (Cotton and Wilbur 1974) or reducing the storage temperature and RH to < 15°C and < 40%, respectively (Howe 1965). Hyde and Burrel (1973) and Peterson et a l . (1956) reported that atmospheric concentrations of oxygen below 1% are s u f f i c i e n t to allow c e r t a i n microorganisms, p a r t i c u l a r l y yeasts, to propagate and give a mouldy appearance to grains, but below 0.2% oxygen most fungi on damp grain were i n h i b i t e d . The remaining conditions (5, 6 and 7) a f f e c t i n g the development of storage fungi, mentioned previously, merely enforce the importance of storing clean, sound grain. Since the outcome of these conditions are so strongly dependent on conditions 1 - 4 , which have been b r i e f l y discussed, i t i s not of great interest to proceed further on these points. The detection of fungi in grain may be carried out either by i n d i r e c t or d i r e c t methods. The i n d i r e c t methods consist of measuring: - 15 -(1) f a t t y acid l e v e l s , (2) temperature.and (3) ge r m i n a b i l i t y . The d i r e c t methods involve: (1) microscopic examination and (2) c u l t u r i n g (Christensen and Kaufmann 1969). The i n d i r e c t methods are normally s u f f i c i e n t f o r recognizing p o t e n t i a l spoilage hazards. In order to complete t h i s section on storage fungi, two more to p i c s w i l l be mentioned separately to further substantiate the importance of proper and safe storage of gra i n . These topics are mycotoxins and spontaneous heating. 3.2.2.1 Mycotoxins Mycotoxins (to x i c metabolic products of fungi) can be to x i c to humans and animals, consequently eliminating the use of infected grain as food or feed (Scott 1973). Mycotoxins have the p o t e n t i a l of e x i s t i n g in any grain that favours the development of storage fungi. About 96 fungal species are suspected of causing mycotoxins (Briggs 1978). Primary storage fungi are: (1) A s p e r g i l l u s flavus which produces a f l a t o x i n - the most common and to x i c mycotomxin which i s capable of growing i n almost a l l b i o l o g i c a l material (plant or animal), (2) As p e r g i l l u s ochracaus which produces ochratoxin - usually found in small concentrations of most infected grains but i s less t o x i c than a f l a t o x i n , (3) P e n i c i l l i u m which produces toxins and toxicoses - common in many samples of grains and i s predominant in some, and (4-) Fusarium which produces toxins and toxicoses common in grains and other plant products of which several species are known to produce potent toxins (Christensen and Kaufmann 1974). - 16 -3.2.2.2 Spontaneous heating Spontaneous heating, the s e l f heating of bulk grain, i s primarily a function of storage fungi invasion and only s l i g h t l y due to grain r e s p i r a t i o n (Wallace 1973). K i r i l e n k o et a l . (1977) recorded a corresponding increase in the microbial count with spontaneous heating, suggesting that microorganisms are the main cause of heat production. Due to poor thermal conductivity of grain (Oxley 1948; Briggs 1978), wet spots in bulk grain are susceptible to the development of isolated 'hot spots' where the temperature may r i s e as high as 55 - 65°C (Westermarck-Rosendahl and Ylimaki 1978) and even 70-75°C when bacteria become involved in the f i n a l stages of d e t e r i o r a t i o n (Christensen and Kaufmann 1974). T r i s v y a t s k i i (1969) has l i s t e d numerous instances where spontaneous heating, o r i g i n a t i n g in a small area of the grain bulk, has spread throughout the bulk v i r t u a l y destroying the entire mass. Therefore, he suggests that, even under seemingly ideal conditions, grain storages be monitored routinely to prevent unwarranted spoilage. In conclusion, Briggs (1978) has named several researchers, who have attempted to delimit g r a p h i c a l l y the conditions under which d e t e r i o r a t i o n occurs. However, due to the many factors involved (moisture, temperature, fungi, oxygen, e t c . ) , these graphs are often incomplete and o f f e r , at best, only tentative guidelines for s p e c i f i c conditions and grains. 4. Storage Methods and Treatments Throughout the years, s c i e n t i s t s have been developing new storage methods to improve the preservation of cereal grains. Due to the - 17 -magnitude of spoilage caused by the numerous destructive f a c t o r s , which were discussed e a r l i e r , i t i s apparent that good storage and preserving methods are e s s e n t i a l in order to increase grain longevity. As the requirement for more food and feed increases, so does the range over which these commodities are grown and, u l t i m a t e l y , the variables r e l a t i n g to t h e i r harvesting and storage. This becomes evident with the harvesting of high-moisture grain for feed and the various suggested methods for storing t h i s vulnerable product. The main methods to date for s t o r i n g high-moisture grain are: (1) a i r t i g h t storage, (2) chemical preservation and (3) r e f r i g e r a t e d storage - the l a s t mentioned method being the least common for high-moisture grain, but i t i s a big factor in helping other preservative methods since cooler ambient temperatures follow the autumn harvest. 4.1 A i r t i g h t Storage/Controlled Atmosphere A i r t i g h t storge of grain dates back to ancient times where underground p i t s were used i n d r i e r regions of the Middle East, Europe, America and A s i a . Hyde (1974) l i s t e d several early authors dating back to 1842, giving d e t a i l s of t h e i r methods. Argentina s t i l l has large underground f a c i l i t i e s for hermetic storage ( T r i s v y a t s k i i 1969). In some Arab countries described by Kamel (1980), grain remained in good order in underground p i t s c a l l e d 'madfans' for as long as 10 years. Although the advantages of a i r t i g h t storage have been well recognized for the storage of both dry and high-moisture grain, the method has been slow to develop commercially (Hyde and Burrel 1973), despite the - 18 -r e l a t i v e cheapness of some storage structures reported by K r a l l (1972) and Michelognoli (1980). However, i f the high-moisture barley concept i s to develop f u l l y , one may expect a i r t i g h t storage to p r e v a i l over other methods of preservation, e s p e c i a l l y in today's pollution-conscious world. 4.1.1 P r i n c i p l e s of A i r t i g h t Storage The basic p r i n c i p l e for a l l a i r t i g h t storage i s the same -depletion of the oxygen in the storage structure to a l e v e l which w i l l k i l l or i n a c t i v a t e a l l harmful aerobic organisms before they are able to p r o l i f e r a t e and damage the grain ( T r i s v y a t s k i i 1969; Hyde 1973). However, the l e v e l of oxygen depletion, required for optimal storage, w i l l depend on the moisture content of the grain, as the minimum requirements for mould and insects varies (0.2 and 2.0%, r e s p e c t i v e l y ) , as mentioned previously. When storing grain under 14% moisture, which i s the minimum requirement for mould growth (Christensen and Kaufmann 1974), the a i r t i g h t seal need not be as s t r i c t as i f storing grain above 14% moisture which favours mould development. Therefore, storing high-moisture grain under a i r t i g h t conditions requires proper f a c i l i t i e s to maintain an anaerobic state and prevent the ingress of a i r through small leaks, which would prove disastrous (Hyde 1973). Oxygen free conditions can be created n a t u r a l l y or a r t i f i c i a l l y in an a i r t i g h t grain bulk. T r i s v y a t s k i i (1969) l i s t e d three methods for obtaining an anaerobic environment: (1) automatic preservation -the r e s p i r i n g of a l l l i v i n g components causes an accumulation of carbon dioxide and depletion of oxygen, (2) gaseous preservation - by - 19 -introducing inert gases to expel the a i r from the intergranular spaces and (3) vacuum preservation - by withdrawing a i r from the grain bulk. The f i r s t method, automatic preservation, i s obviously the most convenient and economical and probably the most fe a s i b l e for high-moisture grain, with the r e s p i r a t i o n rate of the microbial population being high, depletion of oxygen would be rapid ( T r i s v y a t s k i i 1969, Wallace 1973 and Bothast et a l . 1975). This method works best when the sealed granary i s f i l l e d to capacity allowing for minimal a i r reserves for aerobic r e s p i r a t i o n . Hyde (1974) reported carbon dioxide l e v e l s as high as 95% within 20 days of storage in a completely sealed container holding grain over 16% moisture. However, in commercial metal s i l o s there i s usually some escape of carbon dioxide and the concentration generally s t a b i l i z e s between 15 and 25%, even during emptying. The decrease in carbon dioxide concentration i s less i n f l e x i b l e bag s i l o s , which respond to pressure changes without loss of gas to the a i r (Hyde and Burrel 1973). The actual concentration of carbon dioxide concentration i s often i n d i c a t i v e of a low oxygen concentration (Navarro and Calderon 1980). The second method, gaseous preservation, i s not commonly used but does have d i s t i n c t advantages under ce r t a i n circumstances. Many workers hoped that gaseous preservation would reduce anaerobic fermentation and i t s e f f e c t s on grain. Experiments by Hyde (1970), showed that premature oxygen-free conditions did not eliminate fermentation, but due to the cooling e f f e c t of flushing with carbon dioxide, losses attributed to fermentation were reduced s l i g h t l y . Hyde (1974) reported that purging of barley with carbon dioxide as a common procedure in France. However, - 20 -Briggs (1978) deemed gaseous preservation, with either carbon dioxide or nitrogen, to be purely uneconomical. This method of preservation may also be referred to as 'controlled atmosphere storage'. B a s i c a l l y , a l l the same p r i n c i p l e s , aimed at increasing grain storage longevity, mentioned about a i r t i g h t storage (automatic preservation) apply to con t r o l l e d atmosphere storage (Banks and Annis 1980; Busta et a l . 1980; Gay 1980). Because of the expense involved in c o n t r o l l i n g the atmosphere, t h i s method i s being mainly developed for the preservation of food grains (Rannfelt 1980 and Tranchino 1980) where t a i n t s , discolourations and fermentations are not allowed (Hyde and Burrel 1973; Christensen and Kaufmann 1974). Nonetheless, the feed industry i s bound to gain from t h i s technology as i t i s further developed. Once high-moisture grain i s in an oxygen-free state, anaerobic r e s p i r a t i o n may take place by some yeasts and bacteria r e s u l t i n g in a fermentation of the grain (Hyde and Burrel 1973) much l i k e that of sila g e (Muir and Wallace 1971). K r a l l (1972) suggested adding moisture to barley under 25% prior to a i r t i g h t storage to assure good fermentation and safe storage. It may well be noted here that a l l grain stored hermetically, independent of moisture content, should not be considered for sowing due to a severely reduced, and possibly zero v i a b i l i t y in even dry grain ( T r i s v y a t s k i i 1969; Hyde and Burrel 1973; Briggs 1978). 4.1.2 Storage F a c i l i t i e s Several tested storage f a c i l i t e s for hermetic storage of high-moisture grain have been suggested by K r a l l (1972), Hyde (1974), - 21 -Briggs (1978) and Michelagnoli (1980). These structurs vary considerably in technical design, s i z e , convenience and cost. For the purpose of t h i s review, i t would be in the best in t e r e s t to l i s t and discuss the storage f a c i l i t i e s i n d i v i d u a l l y . These structures ranging from simple to complex and varying in effectiveness are as follows: i . Straw bale s i l o s - Simply, straw bales are l a i d on edge in a c i r c l e , of any diameter, with wire around the circumferance to hold the bales together. P l a s t i c sheeting (0.1 mm) i s used to seal the grain from the bales, ground and atmosphere. This method, as could be expected, i s only temporary as the bales provide ideal habitats for rodents, which subsequently eat holes i n the p l a s t i c and cause spoilage. i i . P l a s t i c bags - Black polyethylene p l a s t i c (0.15-0.20 mm thickness) was used to make bags large enough to hold up to a 0.5 tonne capacity. These containers were found to be d i f f i c u l t to f i l l due to a lack of r i g i d i t y . Also, in sunlight the black p l a s t i c promoted a great temperature d i f f e r e n t i a l between the wall and the stored grain. This promoted spoilage near the p l a s t i c as a result of i n t e r i o r condensation. However, workers mentioned by Hyde (1974) found small polyethylene sacks to be quite s a t i s f a c t o r y , e s p e c i a l l y during cooler winter months. Both sacks and bags were unfortunately prone to ruptures and rodent attacks. While the larger bags proved to have several disadvantages, the smaller sacks were reported to be successful providing they were handled c a r e f u l l y . These bags and sacks were sealed with a double t i e or by heat s e a l i n g . i i i . Paper bags - These bags, s i m i l a r to those used for f e r t i l i z e r , are 3-ply, p o l y - l i n e d , paper bags. The bags are square and - 22 -f a i r l y r i g i d making loading easier than with p l a s t i c bags. Capacity of the bags varies up to 730 Kg and they are reported as being quite e f f e c t i v e f o r over 8 months i f provided with an a i r t i g h t s e a l . i v . F l e x i b l e bag s i l o s - Butyl rubber and PVC bags, which stand free or are supported by wire mesh, are in commercial production and in f a i r l y wide use in B r i t a i n . These bags hold between 20-60 tonnes and are equipped with an aperture so that an auger may be inserted without opening the bag. As the high-moisture grain i s used, the rubber bag coll a p s e s automatically reducing any head space for a i r to accumulate. K r a l l (1972) noted a l i f e expectancy on these bags of over 5 years and believed the bags met the necessary requirements of high-moisture barley storage. v. Tower and bunker s i l o s - These s i l o s appear to function best with very damp grain (25-30% moisture or more) which has been r o l l e d or ground for better compaction. In these open-top and open-end structures, the grain i s usually covered with p l a s t i c sheeting and organic residues or other cheap materials ( t i r e s ) to make an a i r t i g h t s e a l . However, once the grain i s to be fed, the safety of the grain becomes dependent mainly on a ' b i o l o g i c a l ' seal which co n s i s t s of the exposed surface layer (5-8 cm) of the g r a i n . As a r e s u l t , once feeding commences i t i s important to remove the surface layer frequently to prevent spoilage. These tower and bunker s i l o s are generally constructed of cement and have proved most successful with processed grains. v i . Metal s i l o s - I d e a l l y , metal s i l o s should be of welded construction to prevent leakage, but bolted construction with caulked - 23 -seams have been more common due to lower cost. The metal i s either galvanized or treated with epoxy-resins or, more recently, finished with a strong vitreous-enamel. This l a s t treatment protects the s t e e l best from corrosive silage acids. Vitreous-enamelled or 'glass li n e d ' s i l o s were o r i g i n a l l y developed i n the U.S. for grass s i l a g e , but have since been widely used for high-moisture grain. Both K r a l l (1972) and Hyde (1974) have noted papers on the management of these s i l o s . It would appear from the l i t e r a t u r e that these s i l o s , with bottom unloading mechanisms, provide a near id e a l environment for storing high-moisture grain. Bridging due to compaction or freezing was not a concern with whole barley up to 30% moisture ( K r a l l 1972). v i i . Concrete domes - Pneumatically formed reinforced concrete domes as described by Michelagnoli (1980), would appear to be the most recent innovation in grain storage technology. The domes, although j u s t recently developed, range from 30-40 m in diameter and have a capacity of 7,500 - 10,000 m3. An economic savings of 40-60% over conventional concrete storage systems was quoted as a result of simple technology and low labour costs. This method of storage was practised in Pakistan with reportedly successful r e s u l t s for both opened and sealed storage. Capital costs of purchasing and constructing these various structures would obviously vary immensely. Consequently, any one type of storage mentioned and possibly others not mentioned, could be su i t a b l e for safe storage depending on the l o c a l conditions confronted by the farmer. Also, a l l a i r t i g h t storage methods for high-moisture grain are faced with the concern regarding the number of mould-free days - 24 -for extracted grain. Once removed from storage, the grain i s back into an aerobic atmosphere and depending on atmospheric temperature and RH, the grain may remain unspoiled for only a few days or as long as a week (Hyde 1974). Therefore, good management and labour practices are e s s e n t i a l i f spoilage i s to be minimized in feeding s i t u a t i o n s . 4.1.3 Changes During A i r t i g h t Storage Changes in hermetically stored grain are r e l a t i v e to the degree of r e s p i r a t i o n taking place in the grain. These changes include v i a b i l i t y , intergranular a i r , baking q u a l i t i e s , biochemical and dry matter - and a l l are dependent on moisture content and temperature ( T r i s v y a t s k i i 1969; Hyde 1974; Briggs 1978). Above 16% moisture, under anaerobic conditions, grain undergoes changes that a f f e c t the commercial value and uses of the grain (Hyde and Burrel 1973). V i a b i l i t y of the grain decreases with germination of the grain f a l l i n g to zero in only a few weeks at moisture contents of 22% or more (Hyde 1965; Meiering et a l . 1966). Carbon dioxide production in intergranular a i r increases dramatically, s t a b i l i z i n g at 15-25%, and oxygen concentration drops s i g n i f i c a n t l y (less than 2.0%) in grain stored in commercial metal s i l o s (Burmeister et a l . 1966; Hyde and Burrel 1969; 1973). Although Hyde (1974) reported that bread-making q u a l i t i e s of hermetically stored wheat at 17% moisture rarely deteriorated and Meiering (1966) found s a t i s f a c t o r y baking q u a l i t i e s in grain stored for 2 months at 21-22% moisture in hermetic structures. These r e s u l t s were confirmed by Hyde (1974), who compiled r e s u l t s on biochemical changes In wheat stored hermetically at varying moisture contents (Table 3). - 25 -Table 3. Some biochemical changes i n wheat a f t e r 7 months of hermetic ( a i r t i g h t ) storage. Moisture Ash A c i d i t y T o t a l Content Content (on Ale) Nitrogen E x t r a c t ) % % % 12.1 1.70 3.6 2.74 12.1 1.68 4.2 2.73 14.0 1.69 4.0 2.81 16.4 1.72 4.2 2.64 17.7 1.78 4.2 2.66 19.9 1.73 5.6 2.68 Reducing Non-Fat Sugar Reducing Starch Sugar % % % % 2.05 0.16 1.96 65.0 1.87 0.10 2.05 64.0 1.86 0.15 2.04 64.3 1 .91 0.28 1.62 65.0 1.91 0.36 1.44 64.5 1.90 0.82 0.81 64.1 Source: Hyde (1974) However, as the moisture content i n c r e a s e s so does the degree of a l t e r a t i o n of the chemical composition i n the g r a i n when stored h e r m e t i c a l l y . Up to 25% moisture, there i s l i t t l e i n c r e a s e i n a c i d i t y and a non-detectable d i f f e r e n c e i n p r o t e i n content ( N i k i t i n s k i i 1955; Shvestova and Sosedov 1958) . At moisture l e v e l s beyond 25% the main change i s an increase i n reducing sugars and decrease i n nonreducing sugars (Hyde and B u r r e l 1973; Hyde 1974). Also at t h i s moisture content and above, fermentation l i k e that of s i l a g e takes place and a c i d i t y i n c r e a s e s along with a t y p i c a l s i l a g e smell and darkening of the kernels (Fos t e r et a l . 1955; Meiering et a l . 1966). These f i n d i n g s support K r a l l ' s (1972) recommendation to add water to g r a i n under 25% moisture i n order to develop a good fermentation, as mentioned p r e v i o u s l y . Although, Hyde and B u r r e l (1973) noted from t h e i r unpublished t e s t s that many of the changes a s s o c i a t e d with a i r t i g h t storage are a f u n c t i o n of temperature and do not occur at n e a r - f r e e z i n g temperatures. These f i n d i n g s can help e x p l a i n d i s c r e p a n c i e s w i t h i n the l i t e r a t u r e regarding - 26 -the s t o r a b i l i t y of grain stored hermetically at varying moisture contents and temperatures. Losses in dry matter content also occur during storage and are a function of carbon dioxide production from the moist grain (Steel and Saul 1962). Below 18% moisture Burmeister et a l . (1966), Dexter et a l . (1969) and Meiering et a l . (1966) found n e g l i g i b l e losses in dry matter content. At 22-25% moisture, dry matter losses are usually lower than 1% (Hyde and Burrel 1973), but Forbes (1965) reported dry matter losses at 2% for barley at 22% moisture. Again, these d i f f e r e n c e s could be accounted for by temperature v a r i a t i o n s with warmer ambient temperatures increasing biochemical a c t i v i t y and dry matter losses. When moisture i s greater than 30%, dry matter losses often increase to 3-4% in barley (Forbes 1965; Meiering et a l . 1966). Forbes (1965) also found dry matter losses to be lower in reconstituted grain than n a t u r a l l y damp gr a i n . 4.1.4 N u t r i t i o n a l Values High-moisture grains such as corn, barley, wheat, oats and sorghum when fed to c a t t l e , sheep or swine are generally equivalent to dry grain on a dry matter basis (Isaacs 1962; T r i s v y a t s k i i 1969; Livingstone et a l . 1971; M e r r i l l 1971; Forsyth et a l . 1972; K r a l l 1972) . Hyde (1974) concluded that feeding high-moisture grain resulted i n a los s of feed e f f i c i e n c y with pigs but not c a t t l e . In some t r i a l s high-moisture corn was reported as being superior to i t s dry counterpart on a dry matter basis in c a t t l e (McKnight et a l . 1973). However, data from high-moisture grain experiments should be c a r e f u l l y interpreted since ensiled high-moisture grain contains v o l a t i l e constituents which - 27 -may be l o s t during oven drying. These losses would tend to under estimate dry matter content and, consequently, lead to under-estimated n u t r i t i o n a l values. Oones et a l . (1974) recommended toluene d i s t i l l a t i o n for precise dry matter determination of ensiled products. However, Ware et a l . (1977) defended the accuracy of oven drying high-moisture grain. They stated that ensiled grain has a lower percentage of v o l a t i l e products than ensiled forage, and therefore, oven drying high-moisture grain, at tempertures less than 100°C, does not cause s i g n i f i c a n t losses of v o l a t i l e substances. In a t r i a l conducted by Livingstone et a l . (1971), high-moisture barley (28.8%) was compared to dry barley and acid-treated high-moisture barley in pigs. Dry matter consumption was consistent for a l l three treatments, but feed e f f i c i e n c y and average d a i l y gain were lowest in pigs fed high-moisture barley. Dry matter and nitrogen d i g e s t i b i l i t y were 82.5, 81.3, 80.6 and 84.7, 82.2, 80.2 for dry, high-moisture and acid-treated barley, respectively. Forbes (1965) reported s i m i l a r r e s u l t s , but observed a higher nitrogen-retention in pigs fed high-moisture barley (24.6%). The increase in nitrogen-retention was, however, not great enought to improve growth or carcass t r a i t s . In a review by Isaacs (1962), no conclusive evidence was found to suggest that high-moisture corn was superior to dry corn in monogastrics, even though some North American papers reported superior r e s u l t s with high-moisture corn in pigs. Feeding 340 steers in 10 d i f f e r e n t t r a i l s over 7 years, K r a l l (1972) found high-moisture barley to have an o v e r - a l l advantage in average d a i l y gain of 0.06 Kg/day over dry barley. However, during the - 28 -i n i t i a l 28 days on feed the advantage, in favour of high-moisture barley, was 0.58 kg/day or a 48% increase. But, t h i s advantage was v i r t u a l l y n u l l i f i e d by the time the steers reached slaughter weight. K r a l l (1972) concluded that the real n u t r i t i o n a l benefits were obtained by bringing steers on to f u l l feed with high-moisture barley and then changing over to dry grain. Due to the greater a c c e p t a b i l i t y of the high-moisture grain with fewer digestive upsets, the turn-over time in the feedlot was reported to be reduced by as long as 15 days. These advantages may in part be due to higher crude f i b r e and nitrogen l e v e l s in high-moisture barley (Marx 1978). As stated e a r l i e r , f i b r e l e v e l s are often higher as the percentage of thins and husks increases ( K r a l l 1972) and the soluble portion of nitrogen increases during the e n s i l i n g process (McKnight et a l . 1973; Oones et a l . 1970). These two factors are b e n e f i c i a l to the ruminant when being adapted on to f u l l feed by helping to increase the rate of passage and preventing acidosis and bloat. Improved feed e f f i c i e n c y and carcass grades in steers fed high-moisture barley were also reported by K r a l l (1972) . Similar findings with c a t t l e fed high-moisture sorghum (25-30%) have been observed as well (Plasto 1971). Losses in dry matter occur in ensiled high-moisture grains due to microrganisms u t i l i z i n g soluble carbohydrates during fermentation and l i b e r a t i n g v o l a t i l e organic acids, ethanol and carbon dioxide (Christensen and Kaufmann 1974). However, Ware et a l . (1977) have stated that any increase observed in the feeding value of high-moisture grain i s partly contributed to by the fermentation process which increases the soluble f r a c t i o n s of carbohydrate and nitrogenous - 29 -compounds, and thereby increasing the d i g e s t i b i l i t y . Dones et a l . (1974) also suggested that the longer retention time in the gut, observed with high-moisture corn, promotes d i g e s t i b i l i t y , but may at the same time decrease dry matter feed intake. High-moisture grain must s t i l l be mechanically processed to maintain favourable feeding values in both ruminants and monogastrics (Forbes 1965; Livingstone et a l . 1971; K r a l l 1972). In high-moisture corn a vitamin E-selenium deficiency has been reported by Moran et a l . (1974a) when fed to ducks. Apparently, microbial a c t i v i t y destroys substantial quantities of tocopherol i n moist corn which may aggravate an already e x i s t i n g selenium d e f i c i e n c y . The consequences are a reduction in growth performance and ultimately death in b r o i l e r s (Moran et a l . 1974b). Severe d e f i c i e n c i e s of vitamin E have caused muscular dystrophy in lambs (Whiting et a l . 1949) and reproductive f a i l u r e in rats (Draper et a l . 1964). It i s not l i k e l y that destruction of tocopherols in ensiled corn i s of great concern as long as the p o t e n t i a l of the problem i s recognized. Since many of the same moulds i n f e c t i n g corn also attack barley and other grains (Christensen and Kaufmann 1969), i t i s conveivable that s i m i l a r conditions may arise in barley contaminated with mould. Hazards r e s u l t i n g from tocopherol destruction may be prevented by ensuring a v a i l a b i l i t y of adequate selenium (Moran et a l . 1974a), by feeding green forages or hays r i c h i n vitamin E (Maynard and L o o s l i 1969) or by an intramuscular i n j e c t i o n s of vitamin E. Richardson et a l . (1963) have reported that the major e f f e c t of the development of fungi on grain was to decrease the amount and - 30 -a v a i l a b i l i t y of lysine for turkeys. This e f f e c t may not apply to pigs, but i f i t does, protein quality of barley w i l l most c e r t a i n l y be affected as l y s i n e i s the f i r s t l i m i t i n g amino acid in pigs (Aw-Yong and Beames 1975). 4.2 Refrigerated Storage Damp grain i s commonly ve n t i l a t e d , to prevent heating due to microbial a c t i v i t y , in an attempt to prevent d e t e r i o r a t i o n (Burrel and Havers 1970). V e n t i l a t i o n helps to maintain the grain temperature only as low as exi s t i n g ambient temperatures; however, r e f r i g e r a t i o n reduces the temperature of the grain below ambient conditions during warmer seasons when spoilage i s of most concern. Hyde and Burrel (1973) have noted that r e f r i g e r a t i o n of grains has been commonly practised with r e l a t i v e l y low moisture (< 17%) grain since the early 1950's, in European countries. Burrel and Laundon (1967) found r e f r i g e r a t i o n close to freezing to be p r a c t i c a l even during hot weather and without thermal i n s u l a t i o n . Cost of power to r e f r i g e r a t e grain, t a i n t free, for 6 months was about half that required to dry si m i l a r grain from 18.1 to 13.8% by heat pump (Burrel 1974). However, r e f r i g e r a t i o n i s not without disadvantages. 4.2.1 P r i n c i p l e s of Refrigerated Storage The main p r i n c i p l e of r e f r i g e r a t i n g high-moisture grain i s to prevent spoilage by decreasing the temperature of the stored grain enough to depress b i o l o g i c a l a c t i v i t y (Burrel 1974) . The poor thermal conductivity of grain makes i t possible to store grain under cool conditions for long periods of time e s p e c i a l l y with the aid of natural - 31 -c o o l i n g . T r i s v y a t s k i i (1969) at t r i b u t e s successful storage of a large proportion of grain grown in Russia to t h e i r cool nights following harvest and long sub-zero winters. It was stated further that natural cooling of high-moisture grain, which could not be dried in time, was i n fact t h e i r only method of preventing grain spoilage on Russian kolkhozes and sovkhozes. Refrigerating grain, dried to 16-17% moisture, to near-freezing l e v e l s appears to be a general recommendation for safe, economic storage ( T r i s v y a t s k i i 1969; Burrel 1974; Briggs 1978). As the moisture content of the grain increases so does the amount of heat that must be removed due to b i o l o g i c a l a c t i v i t y (Disney 1954). Christensen and Kaufmann (1969) pointed out that several v a r i e t i e s of fungi and yeast remain active at even sub-zero temperatures while many others are only dormant. Also, Goffe (1962) reported fungal toxin production at temperatures below freezing. Several species of mites and insects are also capable of surviving at near-zero temperatures (Sinha 1964; Burrel 1974). Therefore, due to the p o t e n t i a l l y high b i o l o g i c a l a c t i v i t y in high-moisture grain (> 17%), r e f r i g e r a t i o n i s recommended only as a temporary storage practice by Burrel (1974) for these grains. Table 4 shows weeks of mould-free storage for barley as temperature and moisture vary. The r e s p i r a t i o n due to b i o l o g i c a l factors also increases the cost of r e f r i g e r a t e d storage, since the grain must be r e c h i l l e d more frequently in order to maintain cool temperatures and prevent musty odours and t a i n t s from developing (Burrel and Laundon 1967). Refrigerated storage of high-moisture grains, therefore, i s most p r a c t i c a l under those conditions as mentioned by T r i s v y a t s k i i (1969), - 32 -Table 4. Estimated maximum number of weeks of mould-free storage of barley at various temperatures and moisture contents. Moisture Temperature,°C Content % -6° 0° 5° 10° 15° 20° 25° 16 >100 >100 >100 >100 >100 40 10.5 17 >100 >100 >100 100 30 10 4 18 MOO >100 80 30 12 5 2 19 > 56 > 32 40 17 6.5 3 1.5 20 56 32 9.5 5.5 3 1.5 1 20* - - 15 8 4 2 1.5 22 40 12 4 2.5 1.5 1 0.5 22* - - 9 5.5 3 1.5 1 24 32 6 2.5 1.5 1 0.5 0.5 24* - - 4.5 2.5 1.5 1 0.5 26 24 4 1.5 1 0.5 0.5 -26* - - 3.5 2 1 0.5 -*With use of adequate v e n t i l a t i o n Source: Burrel (1974). where the grain i s intended for animal feed and c l i m a t i c temperatures w i l l allow for natural c o o l i n g . 4.2.2 Storage F a c i l i t i e s Storage of r e f r i g e r a t e d grain w i l l be most s a t i s f a c t o r y i n f a c i l i t i e s with i n s u l a t i v e properties, not only to r e t a i n low temperatures, but also to prevent harsh freezing in very cold climates (Hyde and Burrel 1973 and T r i s v y a t s k i i 1969). Most conventional storage f a c i l i t i e s , equipped with v e n t i l a t i o n systems, are adequate for r e f r i g e r a t e d storage (Briggs 1978). The grain b i n s / s i l o s are often wrapped with i n s u l a t i n g covers to reduce temperature gradients and cooling costs (Burrel 1974) and prevent losses due to over freezing ( T r i s v y a t s k i i 1969). Other methods to help optimize thermal conditions - 33 -were mentioned by Muir (1973). I t was found that painting metal bins white and providing shade i f in sunny l o c a t i o n s , reduced grain temperatures in the bins by 3-6°C and 2°C, r e s p e c t i v e l y . Bin s i z e also has an a f f e c t on e f f i c i e n c y of r e f r i g e r a t i o n (Briggs 1978). The larger the bulk, the longer the grain w i l l remain coo l , but also large grain bulks w i l l take more time to cool down than smaller ones. This may be a disadvantage i f several grain bins reguire cooling simultaneously, e s p e c i a l l y since a farmer i s normally l i m i t e d to one r e f r i g e r a t o r compressor as a r e s u l t of the high c a p i t a l cost (Burrel 1974). 4.2.3 Changes During Refrigerated Storage R e f r i g e r a t i o n of grain i s , p r e f e r r a b l y , only practised with grains of 17% moisture or l e s s as noted by Hyde and Burrel (1973), Burrel (1974) and Briggs (1978). As a r e s u l t , losses during storage are probably more dependent on moisture content than the method of r e f r i g e r a t i o n i t s e l f (Steel and Saul 1962). Nevertheless, changes do occur in damp r e f r i g e r a t e d grain which become more severe as the moisture content of the stored grain increases. The v i a b i l i t y of grain containing free water (>15% moisture content) (Wallace 1973) i s reduced regardless of r e f r i g e r a t i o n (Roberts 1960). T r i s v y a t s k i i (1969) reported that excessive cooling of moist grain leads to poor germination and spontaneous heating of the grain in the spring months. During r e f r i g e r a t e d storage, pests associated with grain storage are not always adequately c o n t r o l l e d to prevent mustiness, t a i n t i n g , t o x i n production and other related damage in grain, as mentioned e a r l i e r . - 34 -Dry matter losses in grain are a function of carbon dioxide production (C 6H 20 5 + 60 2 = 6C0 2 + 6H 20 + 677kcal), which i s d i r e c t l y dependent on the moisture, temperature and b i o l o g i c a l a c t i v i t y of the grain (Christensen and Kaufmann 1974). Refrigeration a l t e r s one of these i n t e r r e l a t e d components (temperature) and does e f f e c t i v e l y reduce dry matter losses caused by microbial r e s p i r a t i o n (Steel and Saul 1962). Confirming t h i s phenomenon, Hyde and Burrel (1973) showed dry matter losses after 6 months in grain at 21% moisture of 31% at 17.5°C and 1.1% at 5°C. Therefore, r e f r i g e r a t i o n of high-moisture grain does reduce storage losses, but i t should be considered only as a temporary method of preservation. 4.3 Chemical Preservation The recent increase i n the harvesting of high-moisture grains has encouraged the evolution of new viable storage techniques. The a g r i c u l t u r a l potential of chemical preservation was f i r s t recognized in the nineteenth century when farmers used s a l t to help cure t h e i r forage crops (Watson and Nash 1960). More recently, new a c i d i c and a l k a l i treatments have been introduced to enhance the s t o r a b i l i t y of moist grains (Dones et a l . 1974; Montgomery et a l . 1980; Orskov et a l . 1980). Grain preservatives are evaluated by the U.S. Environmental Protection Agency according to mould growth, temperature r i s e , dry matter loss and feeding value ( M i t c h e l l 1972). These chemical treatments must meet government standards and consist of compounds that are metabolized by known pathways; exhibit a very low l e v e l of mammalian t o x i c i t y ; contain no mutagenic, carcinogenic or teratogenic properties; do not adversely affect n u t r i t i v e value of grains; and leave no residue i n animal tissues or products. - 35 -High-moisture grain, chemically preserved, becomes ta i n t e d , making i t u n f i t for human consumption and non-viable, making i t unsuitable for use as seed or malting (Ministry of A g r i c u l t u r e , F i s h e r i e s and Food 1970; Bothast et a l . 1973). Therefore, these grains are of use for animal feeds only. 4-.3.1 Acid Treatments The organic acids ( i . e . propionic, a c e t i c , formic, e t c . ) , for reasons stated in the previous and subsequent sections, are the major compounds used for preserving high-moisture grain, with propionic, a c e t i c and/or combinations being the most favoured (Oones et a l . 1974). 4.3.1.1 P r i n c i p l e s of Acid Treatments The p r i n c i p l e s behind acid preservation allow for treated grain to be stored a e r o b i c a l l y (Oones et a l . 1970). Nelson et a l . (1972) reported that by lowering the pH to 4.0, the microorganisms present on the grain w i l l die and grain r e s p i r a t i o n w i l l stop. The reasons for t h i s pH e f f e c t are reviewed by 3ones et a l . (1974). The a n t i f u n g a l e f f e c t s of f a t t y acids were determined by K i e s e l (1913) who found that: (1) antifungal action of saturated f a t t y acids increases as the carbon atom number increases to 11, (2) branched chain f a t t y acids are l e s s active than corresponding s t r a i g h t chains, (3) hydroxyl group concentration decrease a c t i v i t y and (4) unsaturated f a t t y acids are more active than saturated f a t t y a cids. As a r e s u l t , Twumasi (1970) claimed that propionic acid should have a very low antifungal a c t i v i t y . He found that acids are more active i n the undissociated form due to a more rapid passage through the c e l l membrane than occurs in the case of the - 36 -ion . Also, a c e t i c , propionic and b u t y r i c acids may compete with c e r t a i n amino acids for space on the active s i t e s of enzymes since the organic acids are surface-active (Wyss et a l . 1945). The action of the hydrogen ion may s t i l l be responsible for the i n h i b i t o r y e f f e c t of acids on fungi, causing a l t e r e d c e l l permeability and r e s u l t i n g i n growth i n h i b i t i o n (Marloth 1931; Gershon and Parmegiani 1967). Organic acids are also employed to prevent fermentation and i t s associated l o s s e s . However, Larsen et a l . (1972) found that a c e t i c acid alone was not s u f f i c i e n t to prevent the production of l a c t i c acid (a product of fermentation) i n corn, but when a combination of ac e t i c and propionic acids was employed fermentation was stopped. 4.3.1.2 Acids and N u t r i t i o n a l Values 4.3.1.2.1. Formic Acid and Formaldehyde Often when organic acids are discussed as high-moisture grain preservatives, formic, a c e t i c and propionic acids are most commonly mentioned. However, there i s very l i t t l e l i t e r a t u r e on formic acid per se, regarding grain preservation. Even in a review on organic acid preservation of high-moisture grain by Oones et a l . (1974), formic acid i s mentioned only in passing. It i s surmised that due to the v o l a t i l e and pungent nature of formic acid (Perez-Aleman et a l . 1971; Hyde and Burrel 1973), that most research has been conducted on i t s d e r i v a t i v e formaldehyde which, when present in a i r , oxidizes to formic acid (Merck Index 1976). Consequently, the l i t e r a t u r e reviewed in t h i s section pertains to formic acid only i n d i r e c t l y . - 37 -Several researchers have examined formaldehyde regarding the preservation of products ranging from milk (3ordan and Weatherup 1976 and Vaganova 1976) to hay and silage (Barton and McLaughlin 1976; Sharkey et a l . 1976). Few favourable r e s u l t s in terms of p r e s e r v a b i l i t y and animal productivity have been observed. Barry (1976a) treated several feedstuffs (forages, s i l a g e s , soybean meal, etc.) with formaldehyde and reported an increase in o v e r a l l t o t a l e s s e n t i a l amino acids a v a i l a b l e to ruminants. However, the treatment tended to decrease the a v a i l a b i l i t y of lys i n e , threonine and sulfur containing amino acids in sheep, r e s u l t i n g in poor wool growth. Barry (1976b) found that as the rate of formaldehyde treatment increased, microbial d i g e s t i b i l i t y of nitrogen decreased, acid-pepsin d i g e s t i b i l i t y of nitrogen increased, but o v e r a l l apparent nitrogen d i g e s t i b i l i t y decreased in cannulated sheep fed lucerne hay. Since formaldehyde helps to protect dietary protein from rumen microflora, Barry (1976 a; b) reported application rates in the form of grams of formaldehyde/kg of crude protein (CP). He suggested a range of treatment l e v e l s from 30-50 g/kg CP for low dry matter sil a g e to 6-12 g/kg CP for soybean meal. Peinaar and Renton (1980) treated a b i r d - r e s i s t a n t sorghum grain with a 0.16% formaldehyde sol u t i o n to reduce the high tannin (polyphenol) l e v e l present in the grain. The formaldehyde was successful in reducing the t o t a l reactive polyphenol content, but decreased organic matter intake in sheep, which i s one indicator often used for judging p r o d u c t i v i t y . In another t r i a l , Bothast et a l . (1978) found that high-moisture corn treated with formaldehyde alone showed - 38 -signs of mould growth a f t e r only 20 days. However, during the same experiment the grain was also treated and preserved s u c c e s s f u l l y with methylene-bis-propionate which apparently broke down to propionic acid and formaldehyde within 9 hours a f t e r contacting the wet g r a i n . In f u r t h e r experiments, Bothast et a l . (1978) f a i l e d to produce a mixture of propionic acid and formaldehyde that would preserve wet grain for as long a period as methylene-bis-propionate. According to Zafren and Makarova (1976), formaldehyde (0.2% by weight) also allows for l a c t i c acid fermentation and they found a decrease in dry matter, protein and fat d i g e s t i b i l i t i e s i n c a t t l e fed treated maize. Dordan and Weatherup (1976) found that the addition of 0.15% formalin (37% w/w formaldehyde) in milk resulted in a decrease i n p a l a t a b i l i t y with p i g l e t s . 4.3.1.2.2 Acetic and Propionic Acids In Europe, propionic acid has been used for several years to store damp grain in open storage (Hyde and Burrel 1973). Propionic acid i s t o x i c to moulds and grain and about 10 times the t h e o r e t i c a l dose to c o n t r o l moulds must be applied to preserve g r a i n . This factor could be explained by losses occuring during a p p l i c a t i o n and storage such as penetration into the grain and uneven a p p l i c a t i o n (Briggs 1978). Huitson (1968) suggested that the higher concentrations required were to prevent l a t e r microbial contamination and, consequently, increase the storage l i f e of moist gr a i n . Bowland et a l . (1971) included a mixture of 40% a c e t i c , 40% propionic and 20% b u t y r i c acids up to a l e v e l of 8% in swine r a t i o n s . - 39 -w i thou t any adverse e f f e c t s on feed i n t ake or average d a i l y g a i n . At a 4% i n c l u s i o n r a t e , the p igs gained weight f a s t e r and conver ted feed more e f f i c i e n t l y than an imals on c o n t r o l d i e t s . These l e v e l s o f i n c l u s i o n are f a r beyond the e f f e c t i v e p r e s e r v a t i o n l e v e l of p r o p i o n i c a c i d (0 .5 -1 .5% w/w) f o r h i gh -mo i s tu re corn rang ing from 15-35% m o i s t u r e , sugges t ing tha t the a d d i t i o n of a c i d does not adve rse l y a f f e c t the a n i m a l ' s per formance. L e v e l s of a p p l i c a t i o n f o r p r o p i o n i c ac i d i n c r e a s e wi th mo is tu re con ten t i n the g r a i n and leng th of s to rage (Table 5 ) . B r i g g s (1980) Tab le 5 . A p p l i c a t i o n r a tes of p r o p i o n i c a c i d f o r h i gh -mo is tu re g r a i n . % P r o p i o n i c Ac i d ( a i r dry b a s i s ) K e r n e l Mo is tu re (%) 6 Months Storage 1 Month Storage 18 0 . 4 5 * 0 .35 20 0.50 0.40 22 0.60 0.45 24 0.70 0.50 26 0.80 0.55 28 0.95 0.65 30 1.10 0 .80 35 1.40 1.15 40 1.75 1.40 *The amount of p r o p i o n i c a c i d shou ld be i nc reased by 3% fo r each a d d i t i o n a l month of s to rage over 6 months. Source: Oones et a l . (1974) . gave more gene ra l f i g u r e s sugges t ing tha t f o r g r a i n of mo is tu re con ten ts 18-20% and 21-25%, p r o p i o n i c a c i d equal to 0.8% and 1.0%, r e s p e c t i v e l y , o f the a i r dry weight of g r a i n shou ld be a p p l i e d f o r adequate s to rage p r o t e c t i o n . - 40 -Combinations of propionic and a c e t i c acids (applied at 1.25%) were compared to propionic acid alone to measure the p r e s e r v a b i l i t y by Larsen et a l . (1972). There were no di f f e r e n c e s among the combinations except for small amounts of l a c t i c acid production when a c e t i c was used alone, but a 1:4 r a t i o of pr o p i o n i c - a c e t i c acid suppressed fermentation within the g r a i n . When propionic acid i s used alone ammonical-nitrogen i s elevated (Otterby and Murphy 1971). These and other r e s u l t s from Oones et a l . (1970), Oones (1970) and Young et a l . (1970) helped lead to a commercially produced product c o n s i s t i n g of i n i t i a l l y 60:40 and subsequently 20:80 ac e t i c and propionic acids (Chemstor, Celonese Canada Ltd., Edmonton, A l b e r t a ) . B r i t t and Huber (1976) found t h i s l a t t e r combination of ace t i c - p r o p i o n i c acid inadequate to preserve shelled corn at 29% moisture at a l e v e l of 1.2% of the mixture. The l e v e l s of a p p l i c a t i o n recommended for Chemstor (Table 6) are s l i g h t l y higher than Table 6. Ap p l i c a t i o n rates of a c e t i c - p r o p i o n i c (60:40) acid for high-moisture grain as recommended by Chemstor*. Grain Moisture (%) Acid by Weight (%) Kg/tonne 15-18 0.80 8.0 19-21 0.95 9.5 22-24 1 .15 11.5 25-27 1.30 13.0 28-30 1.50 15.0 31-33 1.65 16.5 34-36 1.80 18.0 37-40 2.00 20.0 *Chemstor, Celanese Canada Ltd., Edmonton, Alb e r t a . those of propionic acid alone. Oones et a l . (1974) reviewed the l i t e r a t u r e regarding the n u t r i t i v e values of acid-treated high-moisture grains and found them to - 41 -be as good or better i n c a t t l e , sheep and pigs. References were made mostly regarding increases i n feed e f f i c i e n c y and average d a i l y gain. Holmes et a l . (1973) reported that acid preservation ( a c e t i c and/or propionic) of high-moisture corn causes a p a r t i a l "predigestion", p r i o r to feeding, by hydrolysis of starch molecules during storage. Also, i t was found that the retention time of these acid-treated rations i n the stomach was greater than non-treated grains. Consequently, these f a c t o r s , pre-digestion and increased g a s t r i c retention, help to explain equal or better feed e f f i c i e n c y and increased energy and nitrogen retentions as reported by Bayley and Holmes (1972). Similar r e s u l t s were obtained by McKnight et a l . (1973) and McNiell et al.(1971) with ruminants. They found high-moisture grain to have a longer ruminal re t e n t i o n time than dry grain, and therefore, c o n t r i b u t i n g to better carbohydrate d i g e s t i o n . In t h i s case, i t would appear that the acid acted only as a preserving agent, since d i f f e r e n c e s were not observed between e n s i l e d high-moisture corn and acid-treated high-moisture corn regarding feeding values or soluble crude protein and free glucose contents which were at much lower concentrations i n dry grain (Gones et a l . 1970; McKnight et a l . 1973). In other experiments, Cole et a l . (1975) found no di f f e r e n c e i n 144 growing pigs fed high-moisture barley stored with 0.8% propionic acid compared with dry barley, at 4 d i f f e r e n t l o c a t i o n s . Nelson et a l . (1973) reported intakes i n pigs to be highest with high-moisture (26%) acid-treated (0.75% propionic acid by weight) sorghum over d r i e r sorghum (16 and 21% moisture), treated and untreated. In an evalution of dried, high-moisture and acid-treated (60% a c e t i c : 40% propionic) high-moisture corn and sorghum, Harpster - 42 -et a l . (1975) found dressing percentages to be highest in lambs fed acid-treated grains. No s i g n i f i c a n t differences were determined between treatments for dry matter, energy or crude f i b r e d i g e s t i b i l i t i e s , but crude protein d i g e s t i b i l i t y was highest with dry grains and then acid-treated grains. T a i t (1979) reported no difference in average d a i l y gain or feed e f f i c i e n c y in sheep fed high-moisture barley treated with an acetic-propionic mixture (60:40), but noted a s i g n i f i c a n t increase in organic matter d i g e s t i b i l i t y favouring dry barley. Tonroy and Perry (1974), using the same acid mixture as Tait (1979) and Harpster et a l . (1975), found in v i t r o dry matter d i g e s t i b i l i t y to be higher in treated high-moisture corn than in dry corn and the reverse for starch concentration, throughout a 72-hour incubation period. In dairy c a t t l e , Ingalls et a l . (1974) found milk production to be the same in cows fed acid-treated high-moisture barley or ensiled high-moisture barley. These levels of production were lower than those obtained for dry untreated barley. F i n a l l y , Lazor et a l . (1978) compared a feed mixture treated with 0.3% propionic acid or 0.5% calcium propionate or none, in c a t t l e . At temperatures ranging up to 30°C both preservatives i n h i b i t e d mould growth well. Average d a i l y gain and feed e f f i c i e n c y were improved by 1.5 to 1.7% and 1.4- to 3.9% for propionic acid and calcium propionate, r e s p e c t i v e l y . However, a disadvantage of calcium or sodium propionate i s t h e i r r e l a t i v e i n s o l u b i l i t y in water (Wallace 1973) , which i s compounded by the higher concentration required over propionic acid to prevent mould growth (Goering and Gordon 1973; Lazor et a l . 1978). - 43 -4.3.1.2.3 Summary There appears to be no question that a c e t i c and propionic acids are good preservatives as long as the s o l u t i o n i s applied evenly so that i t i s not necessary to r e l y on acid d i f f u s i o n to prevent fungal spoilage (Hyde and Burrel 1973). However, there i s some controversy regarding feeding values of treated grains, but they seldom range s i g n i f i c a n t l y below c o n t r o l treatments i n e i t h e r monogastrics or ruminants ( M e r r i l l 1971; 3ones et a l . 1974). 4.3.2 A l k a l i Treatments A l k a l i treatments have only recently been considered for grain preservation. Orskov and Greenhalgh (1977) and Bothast et a l . (1973) apparently i n i t i a t e d research dealing with sodium hydroxide (NaOH) and ammonia (NH3), r e s p e c t i v e l y . Both treatments o r i g i n a t e d i n forage studies and were subsequently adopted by researchers studying storage and n u t r i t i o n a l aspects of gra i n . Much of the work to date with NaOH has concentrated on s p e c i f i c feeding values i n ruminants only, neglect-ing nitrogen u t i l i z a t i o n e n t i r e l y and avoiding handling and storage parameters. Ammonia studies appear to be somewhat more balanced, although much base-line information i s s t i l l required. Sodium c h l o r i d e and urea have been studied b r i e f l y as grain preservatives but with l i t t l e or no success. 4.3.2.1 P r i n c i p l e s of A l k a l i Treatments Unlike acid-treated grain, the primary reason for st o r i n g a l k a l i - t r e a t e d , high-moisture grain i s not e n t i r e l y based on safe aerobic - 44 -storage. Orskov and Greenhalgh (1977) o r i g i n a l l y used NaOH as a method of chemically processing grain to increase dry matter d i g e s t i b i l i t y for c a t t l e . It was shown by several researchers that NaOH breaks down the fibrous components ( l i g n i f i e d c e l l u l o s e and hemicellulose) of roughages, thus increasing the d i g e s t i b i l i t y of dry matter (Klopfenstein et a l . 1972; Oayasuriya and Owen 1975; Klopfenstein 1978; Orskov and Macdearmid 1978; Greenhalgh and P i r i e 1979; Church and Champe 1980; Sriskandarajah et a l . 1980; Horton et a l . 1982). Sodium hydroxide i s very e f f e c t i v e i n s o l u b i l i z i n g hemicellulose (Berger et a l . 1981). Also, NH3 preservation was employed by Laksesvela (1981) to increase the nitrogen content of the feed, he was not interested in i t s preserving a b i l i t y . However, both NaOH and NH3 (at least i n i t i a l l y ) have been demonstrated as good po t e n t i a l preservatives. Orskov et a l . (1980) reported e f f e c t i v e storage of grains treated with NaOH in excess of 2.5% ( a i r dry b a s i s ) . Bothast et a l . (1973) found aqueous ammonia to elimin-ate moulds and i n i t i a l l y reduce b a c t e r i a l counts at a concentration of 0.5% NH3 ( a i r dry basis) in wet corn. The mechanisms of a l k a l i preservation are discussed by Orskov et a l . (1979a). They admitted not knowing the true mode of action NaOH has in preventing mould growth, but suggested that pH, Na + concentration and water a c t i v i t y are of 'paramount' importance. It was noted that pH alone could not be the c o n t r o l l i n g f actor, since some groups of bacteria and fungi are able to grow on high pH medium (Christensen and Kaufmann 1969, 1974). Ohta et a l . (1975) i d e n t i f i e d an a l k a l o p h i l i c bacteria which preferred an a l k a l i n e enivronment with a pH between 10-11 for optimum growth, consequently, the pH tolerance of t h i s organism may be 1 - 45 -to 2 units higher. The pH tolerances of microorganisms are dependent on moisture, temperature and the medium on which they are grown. However, most fungi can not survive severe a l k a l i n e conditions, because the membrane of the organism becomes saturated with hydroxyl ions and thereby l i m i t s the entrance of es s e n t i a l anions (Moore-Lander 1972) . Therefore, the hydroxyl ion concentration may be the most s i g n i f i c a n t preserving factor with respect to NaOH preservation. Berger et a l . (1981), however, observed considerable mould growth in several high-moisture grains treated with 3 and 6% calcium hydroxide (Ca(0H) 2), while si m i l a r treatments of NaOH prevented mould growth. The poorer a n t i -fungal a c t i v i t y exhibited by Ca(0H)2 i s probably due to i t s low s o l u b i -l i t y c o e f f i c i e n t (Mortimer 1971). This would e f f e c t i v e l y reduce the number of free hydroxyl ions available to saturate the membrane of the fungi, and thereby making Ca(0H)2 l e s s e f f e c t i v e than NaOH. The f u n g i c i d a l c h a r a c t e r i s t i c s of NH3 appears to be s t r i c t l y due to i t s i n i t i a l stringent asphyxiation properties, since over time readministration of NH3 i s required to prevent mould growth (Bothast et, a l . 1973 and Pe p l i n s k i et a l . 1978). B r i t t and Huber (1976) reported findings that 500-1000 ppm of free-NH3 in the atmosphere i s necessary to prevent fungal growth. Ammonia k i l l s i n f e c t i n g fungi i n high-moisture grain, but after free-NH 3 disappears remaining spores i n i t i a t e new growth (Bothast et a l . 1973). Therefore, B r i t t and Huber (1976) sugges-ted NH3 as a temporary preservative or to be used i n conjunction with a i r t i g h t storage (Mowat et a l . 1981). - 46 -4.3.2.2 A l k a l i s and N u t r i t i o n a l Values 4.3.2.2.1 Sodium Chloride and Urea In a study by Georging and Gordon (1973), cornmeal was reconstituted to 30% moisture and treated with solutions of sodium c h l o r i d e (NaCl) up to 1% of the wet weight. The NaCl provided no protection against mould growth and damage was too extensive to attempt d i g e s t i b i l i t y t r i a l s . These r e s u l t s should not be s u r p r i s i n g since Christensen and Kaufmann (1969 and 1974) reported storage fungi, s p e c i -f i c a l l y the A s p e r g i l l u s species - y\. r e s t r i c t u s and A_. h a l o p h i l i c u s , as being very tolerant of high s a l t concentrations. A^ . h a l o p h i l i c u s can a c t u a l l y grow on s a l t c r y s t a l s i n an agar medium (Christensen and Kaufmann 1974). It i s apparent that the l e v e l of NaCl required to preserve moist grains would probably far exceed the recommended dietary l e v e l of 1.0% (Lloyd et a l . 1978). Orskov et a l . (1979) included urea in barley ranging from 17-26% moisture at 2% of a i r dry g r a i n . M i c r o b i a l a c t i v i t y was c o n t r o l l e d at the higher moisture l e v e l (26%), but not at the lower moisture l e v e l (17%). They suggested that due to the normally higher microbial count of high-moisture barley (26%), the urea was p a r t i a l l y hydrolyzed, producing NH3 and a subsequent antifungal a c t i v i t y . For the lower moisture barley, the urea simply acted as an energy source to enhance fungal growth. There i s also at least one major b a c t e r i a l species, B a c i l l u s p a s t e u r i i , which i s r e s i s t a n t to a l k a l i n e conditions and i s highly u r e o l y t i c (Wiley and Stokes 1972). Orskov et a l . (1979) c i t e d s i m i l a r findings by East German workers. - 47 -Although ruminants can acclimatize to high l e v e l s of urea supplementation with no harmful e f f e c t s , they are also susceptible to urea t o x i c i t y at much lower l e v e l s of i n c l u s i o n when the animal i s f i r s t put on feed (Gallup et a l . 1953). For t h i s reason, in l i t e r a t u r e c i t e d by Austin (1967), i t was recommended that urea should not c o n s t i t u t e more than 2% (DM basis) of the t o t a l r a t i o n for ruminants. Beames (1960) c i t e d minimum acute urea t o x i c i t y l e v e l s i n ruminants i n the order of 0.3 to 0.5 g urea per Kg body weight, which are in agreement with those c i t e d by Austin (1967). Consequently, a 30 Kg lamb fed a r a t i o n c o n s i s t i n g s o l e l y of 2 Kg a i r dry grain treated with 2% urea on an a i r dry basis (as applied by Orskov et a l . 1979), would be consuming 1.3 g urea per Kg body weight per day, which i s well above the minimum acute t o x i c i t y l e v e l s c i t e d e a r l i e r . Mowat et a l . (1981) fed ye a r l i n g Hereford steers high-moisture corn treated with 3.7% (wt/wt D M basis) urea and recorded poorer liveweight gain and feed e f f i c i e n c y . They also noted that hydrolysis of urea to NH3 was taking place and was greatest near the walls of the bin where NH3 was l o s t . Therefore, based on the l i t e r a t u r e presented, i t would appear that urea i s not su i t a b l e for preserving high-moisture grain, e s p e c i a l l y when grain i s used as the sole d i e t , since the l e v e l of urea reguired to preserve the grain may, under some circumstances, be t o x i c to ruminants. 4.3.2.2.2 Sodium hydroxide (NaOH) Whole barley treated with 35g NaOH/Kg ( a i r dry basis) as a 30% s o l u t i o n was as well consumed and digested as ground or r o l l e d barley and better digested than untreated whole grain by c a t t l e (Orskov and - 48 -Greenhalgh 1977; Orskov and Macdearmid 1978). The a l k a l i treatment also gave a slower release of starch than the mechanical treatment which would r e s u l t in l e s s interference with c e l l u l o s e d i g e s t i o n i n roughage-concentrate r a t i o n s . Orskov et a l . (1979 b) compared NaOH (20g/Kg) and propionic acid on whole high-moisture barley (23%) when fed to lambs. Dry matter d i g e s t i b i l i t y was increased by NaOH treatment, but average d a i l y gain and feed e f f i c i e n c y tended to favour the acid-treated grain, no s i g n i f i c a n t d i f f e r e n c e s were observed. In an in s i t u rumen t r i a l , Berger et a l . (1981) showed that the d i g e s t i b i l i t y of NaOH-treated grains increased up to 48 hours i n a f i s t u l a t e d s t e e r . Orskov et a l . (1979 a; 1980; 1981 a) recommended not feeding the grain f o r at least one week a f t e r t r e a t i n g with NaOH in order for the hydroxyl ions to convert to carbonates. This reaction of hydroxyl ions to carbonates acts as a natural buffering mechanism which attempts to reduce the high g r a i n pH induced by the a l k a l i treatment. However, Anderson et a l . (1981) found that whole, high-moisture corn treated with 3.0% NaOH ( a i r dry basis) had a pH of 11.94 compared to whole and r o l l e d high-moisture corn with pH values of 4.53 and 4.81, r e s p e c t i v e l y . Orskov et a l . (1979 a) recorded s i m i l a r pH l e v e l s i n a l k a l i - t r e a t e d , high-moisture barley. Therefore, the a l k a l i treatment s i g n i f i c a n t l y r a i s e s the grain pH and maintains i t throughout storage. Barley and oats were treated with 3.5 and 4.5 g NaOH/Kg, r e s p e c t i v e l y , by Orskov et a l . (1979 c ) . Treated, whole barley gave c o n s i s t e n t l y poorer average d a i l y gains and feed conversion than untreated, whole barley, but treated, whole oats ranked better than untreated, whole oats i n the same categories i n both lambs and st e e r s . - 49 -At the time of slaughter, the rumen contents of the lambs fed the a l k a l i - t r e a t e d grains were s i g n i f i c a n t l y l e s s than those fed untreated g r a i n s . This f i n d i n g was also noted by Orskov et a l . (1981a). These observations help v e r i f y an e a r l i e r statement by Berger et a l . (1981) that NaOH treated grainsincrease the rate of passage. Optimum NaOH treatment l e v e l s for several grains were determined i n complete d i e t s for c a t t l e , based on the d i g e s t i b i l i t y of f i b r e , dry matter and organic matter (Orskov et a l . 1980). The optimal amount of NaOH required varied between c e r e a l s , being about 3.0-3.5% for barley, 4.5-5.0% for oats and 2.5-3.0% for wheat and corn. The d i g e s t i b i l i t y of the 3 grains mentioned l a s t increased more with NaOH treatment than by physic a l processing. Increases in dry matter d i g e s t i b i l i t y of whole untreated grain versus whole treated grain i n steers were from 61 to 83% for barley, 61 to 76% for oats, 83 to 89% for corn and 79 to 88% for wheat. However, Barnes and Orskov (1981) fed steers ad li b i t u m 50% hay and 50% r o l l e d or NaOH-treated (30 g/Kg) barley and found s i g n i f i c a n t l y higher dry matter and organic matter d i g e s t i b i l i t i e s with the die t containing r o l l e d barley. This promoted further i n v e s t i g a t i o n and they determined that 40g NaOH/Kg (versus 30g NaOH/Kg suggested by Orskov et a l . (1980) when grain was the sole feed) was required to obtain s i m i l a r r e s u l t s with treated whole barley as with r o l l e d barley i n roughage-concentrate r a t i o n s . S i m i l a r r e s u l t s were found by Orskov et a l . (1981 c) when they substituted s i l a g e for hay. The d i f f e r e n c e i n ap p l i c a t i o n rate, suggested by Barnes and Orskov (1981) and Orskov et a l . (1981 b), i s l i k e l y due to the increased rate of passage of small p a r t i c l e s from the rumen r e s u l t i n g from the presence of the roughage. - 50 -By increasing the NaOH l e v e l , the rate of digestion in the rumen increases (Orskov and Greenhalgh 1977) and can compensate for the f a s t e r rate of passage when roughages are fed. In growth t r i a l s , NaOH-treated grain generally resulted in lower pr o d u c t i v i t y as compared to whole or untreated, mechanically processed barley in c a t t l e and sheep (Orskov et a l . 1979 a, b; Anderson et a l . 1981; Barnes and Orskov 1981; Orskov et a l . 1981 a, b). This consistent observation could be p a r t i a l l y explained by findings from Anderson et a l . (1981). They reported low f e c a l pH in steers fed a l k a l i - t r e a t e d corn, ad l i b i t u m . According to Wheeler and Noller (1977), f e c a l pH and f e c a l starch are highly inversely correlated, therefore, as f e c a l starch increases f e c a l pH decreases. With a decrease in starch u t i l i z a t i o n , more fermentation w i l l take place in the hind gut and as a result blood-urea w i l l enter the hind gut and, thus, w i l l be excreted with the f e c a l starch. Consequently, the nitrogen d i g e s t i b i l i t y c o e f f i c i e n t i s pulled down due to an increase in f e c a l nitrogen. It may be i n t e r e s t i n g to note at t h i s time, that no one has reported protein u t i l i z a t i o n figures for NaOH-treated grains even though Anderson et al.(1981) mentioned, in the methods of t h e i r paper, f e c a l nitrogen determinations. 4.3.2.2.3 Ammonia (NH^) Much of the i n i t i a l work with ammonia was conducted on roughages, p a r t i c u l a r l y corn stover and straw ( O j i and Mowat 1979; Morris and Mowat 1980; Kiangi and Kategile 1981; Borhami and Sundstol 1982; Horton et a l . 1982). However, some material dealing with n u t r i t i o n a l aspects of ammoniated grain i s a v a i l a b l e . B r i t t and Huber (1975) compared high-- 51 -moisture corn (25%) treated with 1% propionic acid or 1% anhydrous ammonia (added as a 20% s o l u t i o n of aqua ammonia) and stored in concrete-stave s i l o s which provided minimal p r o t e c t i o n . The NH3-treated corn stored for 230 days (over the cool winter months) before i t showed any sign of fungal growth. At t h i s time the recovery of added NH3 was 50%. Dairy h e i f e r s r e a d i l y consumed the N H 3 -treated corn when i t comprised 70% of the r a t i o n dry matter, but only i f treated with molasses. True nitrogen d i g e s t i b i l i t y was higher for propionic treated corn, but nitrogen-retention favoured NH3 corn because of the greater nitrogen intake. Milk y i e l d s were lower in cows fed 0.54% than 0.63% NH3 or 1.0% propionic corn. B r i t t and Huber (1975) concluded that propionic acid was a better fungal i n h i b i t o r than NH3 and suggested that some NH3 could have been binding with carbohydrates and a c t u a l l y promot-ing fungal growth i n the stored corn. In two t r i a l s by Laksesvela and Slagsvold (1980) and Laksesvela (1981), whole barley (15.3% and 25.6% moisture) was treated with 3.0% NH3 ( a i r dry b a s i s ) , supplemented with chopped hay and fed to sheep. The apparent f i b r e and protein d i g e s t i b i l i t e s , c a l c u l a t e d by d i f f e r e n c e , were generally 3 to 5 percentage units higher for NH3-treated barley than untreated whole or r o l l e d barley, with dry matter d i g e s t i b i l i t y being 8 to 10 units higher for NH3 barley. However, i t was not deter-mined i f the chopped hay had any a s s o c i a t i v e e f f e c t on the barley, but for p r a c t i c a l purposes the improvement due to the NH3 was valuable whether i t s e f f e c t was on the barley alone or on barley and the basal d i e t together. The increase in crude protein, due to the addition of NH3, was 3 to 4 percentage units higher for both experiments and may - 52 -have promoted rumen a c t i v i t y and, consequently, higher d i g e s t i b i l i t y c o e f f i c i e n t s . The addition of ammonium hydroxide ( N H 4 O H ) at 3 or 6% decreased DM d i g e s t i b i l i t y of barley, but increased DM d i g e s t i b i l i t y of wheat i n rumen in s i t u experiments (Berger et a l . 1981). Previously, Fulton et a l . (1979) suggested rupturing the seed coat of wheat may be the only change necessary to allow rapid d i g e s t i o n of wheat starch. This statement was encouraged by the fact that ground barley treated with NaOH was digested more r a p i d l y than untreated ground barley and no di f f e r e n c e was found i n s i m i l a r prepared wheat samples. Therefore, NaOH may have some other e f f e c t on barley than just rupturing the seed coat and s o l u b i l i z i n g hemicellulose which N H 3 does not have (Berger et a l . 1981). Ammonium hydroxide-treated, high-moisture corn produced a lower dry matter rate of passage than d i d untreated, high-moisture corn or NaOH-treated, high-moisture corn, and consequently, the NHi+OH treatment produced greater rumen f i l l , p ossibly having a negative e f f e c t on intake (Anderson et a l . 1981). Montgomery et a l . (1980) fed steers maize treated with anhydrous-NH 3, NH40H or methylene-bis-propionate. The feedlot performance tended to be improved i n those fed NH 3-treated corn with a s i g n i f i c a n t advantage in average d a i l y gain for anhydrous-NH 3 o v e r a l l , and NHi+OH over methylene-bis-propionate. However, methylene-bis-propionate was a much superior preservative. An en s i l e d treatment was not included i n the t r i a l . Whole high-moisture corn (28%) was treated with 1,2 and 3% anhydrous-NH 3 (wt/wt DM basis) by Srivastava and Mowat (1980). Applica-t i o n of 2% NH3 (DM basis) was s u f f i c i e n t to eliminate fungal growth i n - 53 -the grain stored and sealed i n p l a s t i c l i n e d drums. The nitrogen content of the grain increased with ammoniation up to the 2% treatment l e v e l and at t h i s l e v e l 35% of the nitrogen, added as N H 3 , was retained following exposure to the a i r for 7 days. Only 56% of the retained N H 3-nitrogen was s o l u b i l i z e d by rumen f l u i d at the 2% treatment l e v e l , but pepsin completely s o l u b i l i z e d the remaining N H 3~nitrogen. The large proportion of nitrogen s o l u b i l i z e d by pepsin may be a r e s u l t of increased a v a i l a b i l i t y of amino acids r e s u l t i n g from a l k a l i n e denatura-t i o n of corn protein (Sanderson et a l . 1978). Srivastava and Mowat (1980) also found a slower rate of starch degradation in N H 3-treated corn which may increase rumen bypass of starch and cause le s s i n t e r -ference with c e l l u l o s e digestion and roughage intake when these treated grains supplement roughage based d i e t s . These findings are p a r a l l e l to those of Orskov et a l . (1978) with NaOH-treated barley. However, p o s s i b i l y i f the rumen bypass of starch i s too great then not a l l the starch w i l l be further degraded and w i l l be excreted, as indicated by Anderson et a l . (1981). Mowat et a l . (1981) conducted a d i g e s t i b i l i t y t r i a l with steers on ammoniated corn (30% moisture) treated s i m i l a r l y to the experiment of Srivastava and Mowat (1980). They reported starch and energy d i g e s t i b i -l i t i e s s i m i l a r to en s i l e d ground corn and an increased acid detergent f i b r e d i g e s t i b i l i t y i n NH3 corn. These data supported e a r l i e r f i n d i n g s (Srivastava and Mowat 1980), suggesting that treatment with 2% NH3 (DM basis) i s s u f f i c i e n t to chemically process whole high-moisture corn. The d i e t used i n the t r i a l (Mowat et a l . 1981) consisted of 40% shelled corn and 60% corn s i l a g e (DM basis) and was f o r t i f i e d with minerals. - 54 -These r e s u l t s demonstrate the e f f e c t of NH3 corn when fed as a supple-ment to s i l a g e and not the e f f e c t of NH3 corn fed alone. 4.3.2.2.4 Summary Sodium hydroxide and ammonia are both f u n g i s t a t i c (Orskov and Greenhalgh 1977; Bothast et a l . 1973) and are capable of preserving high-moisture grain a e r o b i c a l l y , at least temporarily (Orskov et a l . 1979; P e p l i n s k i et a l . 1978). A p p l i c a t i o n l e v e l s of NaOH depend on the intended use of the whole grain, with higher l e v e l s required to promote optimum dry matter d i g e s t i b i l i t y when the grain supplements a roughage based d i e t (Orskov et a l . 1981). In a l l f i n i s h i n g t r i a l s to date, with steers and lambs fed NaOH-treated grain, feed e f f i c i e n c y , average d a i l y gain and some carcass t r a i t s have been c o n s i s t e n t l y poorer as compared to c o n t r o l d i e t s (Anderson et a l . 1981; Barnes and Orskov 1981; Orskov et a l . 1982 a, b). The a p p l i c a t i o n l e v e l of 2% NH3 (DM basis) for corn appears to be n u t r i t i o n a l l y s a t i s f a c t o r y i n roughage based d i e t s (Mowat et a l . 1981), but adequate l e v e l s have not been determined for grains fed as the sole d i e t . P o s s i b l y , these l e v e l s w i l l be more dependent on the preserving q u a l i t i e s rather than the n u t r i t i o n a l values of NH3, unless the grain i s to be stored hermetically or c h i l l e d to prevent or reduce losses of NH 3. However, in s i t u rumen experiments with nylon bags have also proved NH3 as a p o t e n t i a l chemical processor s i m i l a r to NaOH (Srivastava and Mowat 1980) . The advantages of feeding NaOH- and NH 3-treated, whole grain compared to p h y s i c a l l y processed grain are that the rate of dige s t i o n i n - 55 -the rumen i s decreased, rumen pH i s higher and hay intake i s increased (Low and Kellaway, unpublished). Disadvantages of feeding a l k a l i -treated grain include poor grain flow c h a r a c t e r i s t i c s ( P e p l i n s k i et a l . 1978) and high intakes of water associated with the high l e v e l s of sodium (Orskov et a l . 1980). However, as stated e a r l i e r , the negative e f f e c t s of NaOH-treated grain i n f i n i s h i n g t r i a l s tends to d i s c r e d i t the advantages a t t r i b u t e d to NaOH treatment. D i g e s t i b i l i t y values of NH3-treated grain are often improved over untreated grain (Laksesvela 1981). However, because NH3 i s very v o l a t i l e and free - N H 3 must be present i n the intergranular atmosphere to prevent mould growth (Bothast et a l . 1975), NH3 i s poorly suited for aerobic storage of g r a i n . A feedlot evaluation of NH3-treated and untreated grain has, at present, not been reported. 4.3.2.3 Chemical Aspects of A l k a l i - T r e a t e d Grain Apart from the fact that NaOH and NH3 are e f f e c t i v e i n c o n t r o l l -ing m i c r o b i a l p r o l i f e r a t i o n i n moist grain (Bothast et a l . 1973; Orskov and Greenhalgh 1977) and increasing organic matter d i g e s t i b i l i t y i n ruminants (Anderson et a l . 1981; Laksesvela 1981), a l k a l i n e conditions are not without negative side e f f e c t s , e s p e c i a l l y when considering the monogastric animal (De Groot et a l . 1976 b). There are at le a s t three f a c t o r s that can lead to the poor u t i l i -z a t ion of a l k a l i - t r e a t e d grains by monogastrics. F i r s t l y , a l k a l i -treated proteins are very susceptible to racemization as a r e s u l t of an increase i n pH (Hayashi and Kameda 1980). When t h i s occurs, the stereo-s p e c i f i c i t y of several amino acids i s changed from the natural L-form to - 56 -the D-form, which are poorly u t i l i z e d by monogastrics (De Groot et a l . 1976 a). In a review, Berg (1959) l i s t e d references showing u t i l i z a t i o n ranging from p a r t i a l to complete of D-isomers of tryptophan, methionine, phenylalanine, leucine, v a l i n e , h i s t i d i n e arginine and tyrosine, but no u t i l i z a t i o n of the D-isomers of l y s i n e and threonine, which are the f i r s t and second l i m i t i n g amino acids in barley for pigs (Aw-Yong and Beames 1975). When racemization occurs in a non-essential amino acid located near an e s s e n t i a l amino acid residue, the a v a i l a b i l i t y of the e s s e n t i a l amino acid i s also lowered; therefore, racemization of only a s i n g l e amino acid could cause a s i g n i f i c a n t loss of e s s e n t i a l amino acids through lowered p r o t e o l y t i c d i g e s t i b i l i t y of the L-enantiomers (Hayashi and Kameda, 1980). Secondly, a l k a l i treatment causes the c r o s s - l i n k i n g of natural amino acids to form a unnatural d e r i v a t i v e such as l y s i n o a l a n i n e (LAL) (N°-[DL-2-amino-2 carboxyethyl]-L-lysine) which i s derived from l y s y l and dehydroalanyl residues under high pH condi-tions (Hayashi and Kameda 1980; Friedman 1979). Davidson et a l . (1982) have found high l e v e l s of LAL i n NaOH-treated barley as compared to no LAL in untreated g r a i n . Also they found the l y s i n e content to be i n v e r s e l y c o r r e l a t e d with the LAL content in NaOH-treated barley. Such a cross-linkage decreases net protein u t i l i z a t i o n i n r a t s (De Groot and Slump 1969) . The safety of feeding a l k a l i - t r e a t e d foods was i n v e s t i g a -ted by De Groot et a l . (1976 b) in several groups of laboratory animals but not the p i g . They reported that free (as opposed to protein bound) LAL caused hepatotoxic symptoms in rats only. T h i r d l y , the nonenzymatic browning or M a i l l a r d reaction may r e s u l t from heating and a l k a l i n e c o n d i t i o n s . This causes a decreased a c c e s s i b i l i t y of p r o t e o l y t i c - 57 -enzymes to peptide bonds (Hayashi and Naniki 1981). The M a i l l a r d reac-t i o n c o n s i s t s of a carbonyl-amino reaction between the carboxyl groups of reducing sugars (usually glucose, fructose or pentose) and the amino groups of protein, predominantly the epsilon (e) amino groups of l y s i n e . The reaction often renders the protein i n s o l u b l e r e s u l t i n g i n a loss of n u t r i t i v e value (Feeney 1975). In a t r i a l with N H 3-treated corn, B r i t t and Huber (1976) suggested that any benefits gained by adding NH3 were l o s t due to the browning reaction that occurred. The browning of a l k a l i - t r e a t e d grains was also mentioned by Srivastava and Mowat (1980) and P e p l i n s k i et a l . (1978). Recent reports on a l k a l i - t r e a t e d grains i n ruminants (Orskov et a l . 1981 a; Berger et a l . 1981; Anderson et a l . 1981) have not discussed i t s e f f e c t on protein u t i l i z a t i o n , but with the presence of amino acid racemases i n rumen b a c t e r i a (Evered 1981), adverse e f f e c t s common in monogastics should be s i g n i f i c a n t l y reduced i n ruminants. However, many unhydrolyzed racemic amino acids that bypass the rumen and enter the small i n t e s t i n e w i l l be poorly u t i l i z e d , since many of the D-amino acids are not susceptible to protease attack (Woodward and Short 1973). Only recently Davidson et a l . (1982), cohorts of the f i r s t person to report t r i a l s with NaOH-treated grain (E.R. Orskov), rediscovered the importance of the d e t e r i o r a t i o n s that occur i n a l k a l i - t r e a t e d g r a i n s . Hopefully, t h i s w i l l prompt further i n v e s t i g a t i o n s regarding protein u t i l i z a t i o n of a l k a l i - t r e a t e d grains i n both monogastrics and rumin-ants. Anderson et a l . (1981) reported a pH of 11.94 in grain treated with 3% NaOH (DM b a s i s ) , t h i s suggests that the a l k a l i treatment l e v e l s - 58 -suggested by Orskov et al. (1980; 1981a) most certainly create condi-tions classified as 'severe alkali treatment of proteins' as observed by De Groot et al. (1969; 1976a). 4.3.2.4 Experimental Application and Storability of Ammoniated Grain Ammonia-treated, high-moisture grains are not as stable as grains treated with acid or NaOH, when stored aerobically (Peplinski et al. 1978; Van Cauwenberge et al. 1981). Due to the volatile nature of NH3, high-moisture grains, so treated, are left unprotected as the free-NH3 dissipates over time (Lancaster et al. 1974). For these reasons and others, the author felt it was important to discuss the experimental methods and findings, reported thus far, regarding ammoniated grains. High-moisture maize (22-24%) was treated with anhydrous-NH3 (gaseous) or NH4OH (liquid or aqua ammonia or ammonium hydroxide which is produced by bubbling anhydrous-NH3 through H2O) at 0.9% and 1.3%, respectively, and stored in 'airtight' bins equipped with recirculating fans, by Montgomery et al (1980). Anhydrous-NH3 was injected into a bin previously loaded with 13 tonnes of corn. Liquid-NH3 was sprayed on the corn as it passed through the auger en route to storage. For anhydrous- and liquid-NH3, the residual NH3 decreased from 0.9 to 0.63 to 0.41% and from 1.3 to 0.29 to 0.29%, respectively, after one day and six months of storage. Mould growth developed by six months in the anhydrous-NH3 grain and after only five months in the liquid-NH3 grain, due to moisture migration and increasing ambient temperatures. Both dry (15.3% moisture) and damp barley (25.6% moisture) were successfully preserved, during winter months, by injecting anhydrous-NH3 - 59 -i n t o the midd le of a s e a l e d , one tonne c a p a c i t y , po l ye thy lene bag ( L a k s e s v e l a and S l a g s v o l d 1980; L a k s e s v e l a 1980) . The NH3 was admin i s -t e r e d at 30 Kg/ tonne ( a i r dry b a s i s ) i n both c a s e s . H igh -mo is tu re corn (28-30%) was t r e a t e d i n sea led 205 1 drums by i n j e c t i n g 1, 2 , and 3% anhydrous -NH3 (wt/wt DM b a s i s ) , by S r i v a s t a v a and Mowat (1980) and Mowat et a l . (1981) . The h igher c o n c e n t r a t i o n s e l i m i n -a ted f u n g i and yeast and d r a s t i c a l l y reduced b a c t e r i a l c o l o n i e s f o r up to 60 days at which t ime the corn was aera ted f o r seven days , l o s i n g 66% of the added 2% NH3 and a l l o w i n g f u n g i and yeast to d e v e l o p . P r e s e r v a -t i o n was s i m i l a r f o r both 2 and 3% N H 3 , but 1% NH3 was not as e f f e c t i v e ( S r i v a s t a v a and Mowat, 1980) . Lancas te r et a l . (1974) sprayed h igh -mo is tu re c o r n , as i t was augered i n t o s t o r a g e , w i th a 22% l i q u i d - N H 3 s o l u t i o n at a r a t e of 0.48% N H 3 ( a i r dry b a s i s ) . Samples ana lyzed d i r e c t l y from the auger i n d i c a t e d a 19% l o s s of NH3 occu r red du r ing a p p l i c a t i o n , r e s u l t i n g i n on ly 0.39% t o t a l NH3 i n the g r a i n . The g r a i n was s to red i n a wooden b in l i n e d and covered w i th p l a s t i c s h e e t i n g . Dur ing the f i r s t 22 days of s t o r a g e , there was a r e d u c t i o n i n mould count and no i n c r e a s e i n b a c t e r i a , but at 47 days m i c r o b i a l growth had begun. These r e s u l t s are not s u r p r i s i n g s i n c e Bothast et a l . (1975) suggested 5 g N H 3 / K g wet corn to p rese rve f r e s h l y harves ted h igh -mo is tu re corn (27%). L i q u i d - N H 3 (19% N H 3 , w/w) was sprayed on h i gh -mo i s tu re corn (23%) at a r a t e of 1.02% NH 3 (DM b a s i s ) , by P e p l i n s k i et a l . (1978) . The g r a i n was s to red i n a wooden b in sea led w i th epoxy pa in t and c a u l k i n g . Free NH3 reduced to 0.7 and 0.1% a f t e r 3 and 26 days of s t o r a g e . F i v e a d d i t i o n s of anhydrous -NH3 were i n j e c t e d throughout the s to rage pe r i od - 60 -(300 days) to maintain a s a t i s f a c t o r y l e v e l to prevent s p o i l a g e . A t o t a l of 3.04% NH3 (DM b a s i s ) was added to the corn. On a l a b o r a t o r y s c a l e , Van Cauwenberg et a l . (1981) t e s t e d c o n t r o l l e d - r e l e a s e NH3 s o l u t i o n s and l i q u i d - N H 3 f o r p r e s e r v i n g high-moisture corn (25%). Under aerated c o n d i t i o n s , they found that a s o l u t i o n a l l o w i n g immediate r e l e a s e of 0.16% NH3 and slow r e l e a s e of 0.8% NH3 ( a i r dry b a s i s ) preserved b e t t e r than immediate or slow r e l e a s e alone. R e s u l t s from Lancaster et a l . (1974) prove important again, as t h i s t r i a l showed the need f o r an i n i t i a l c o n c e n t r a t i o n of f r e e - N H 3 to prevent m i c r o b i a l growth. The c o n t r o l l e d - r e l e a s e s o l u t i o n s contained N H 3 , urea and urease enzyme. S i m i l a r work was touched on by Orskov et a l . (1979a), when they suggested that the h y d r o l y s i s of urea to NH 3 was r e s p o n s i b l e f o r l i m i t i n g m i c r o b i a l development i n high-moisture b a r l e y . Common occurrences observed i n ammoniated g r a i n are: (1) temperature g r a d i e n t s , (2) moisture and NH 3 m i g r a t i o n , (3) browning and (4) b r i d g i n g or c a k i n g . Temperature g r a d i e n t s have been observed by Lancaster et a l . (1974) and P e p l i n s k i et a l . (1978) w i t h i n l a r g e s t o r e s of g r a i n . In both cases, the temperature has r i s e n s i g n i f i c a n t l y above ambient temperatures and the e f f e c t i s apparently not due to m i c r o b i a l r e s p i r a t i o n but r a t h e r chemical h e a t i n g . Lancaster et a l . (1974) attempted to d u p l i c a t e t h i s response under l a b o r a t o r y c o n d i t i o n s using i n s u l a t e d 205 1 drums, without success. Papers c i t e d by Lancaster et a l . (1974) confirm the d i f f i c u l t i e s i n c u r r e d with attempting t o d u p l i c a t e chemical heating i n g r a i n under l a b o r a t o r y c o n d i t i o n s . Moisture and NH 3 m i g r a t i o n are a d i r e c t r e s u l t of temperature g r a d i e n t s (Howard et a l . 1974). As the core temperature i n c r e a s e s , due to e i t h e r - 61 -chemical or microbial heating, water and NH3 migrate to the cooler surface (Lancaster et a l . 1974). Mowat et a l . (1981) recorded a 23% d i f f e r e n c e in moisture content between the surface and the core of a l k a l i - t r e a t e d grain stored in 205 1 drums. The migration of the moisture to the top of the drums (205 1 drums) resulted from heat being produced from the chemical reaction between the a l k a l i and water. P e p l i n s k i et a l . (1978) reported that moisture migration in NH3~treated corn was coupled with NH3 migration to the surface of the stored g r a i n . As a r e s u l t , the NH3 was more e a s i l y l o s t as free-NH 3 to the atmos-phere. This caused microbial c o n t r o l to become impaired, e s p e c i a l l y i n the lower l e v e l s of the corn where free - N H 3 i s responsible for m i c r o b i a l co n t r o l (Lancaster et a l . 1974). Non-enzymatic browning has been observed in almost a l l NH3-treated grains. McGhee et a l . (1979) found that at 1 and 2% NH3 (DM b a s i s ) , nonreducing sugars were stable in corn, but reducing sugars were d r a s t i c a l l y reduced, at 37 and 60°C. Reducing sugars bind with amino acids in the browing reaction (Feeney 1975) . Dry matter losses in NH3-treated corn were reported by P e p l i n s k i et a l . (1978) and Mowat et a l . (1981) at 14 and 1.4%, r e s p e c t i v e l y . This range could be accounted for by v a r i a t i o n i n a p p l i c a t i o n rates, storage method and duration, degree of microbial a c t i v i t y , ambient temperatures, moisture contents and loss of NH3. More recently, working with ammoniated barley straw, Borhami et a l . (1982) have attempted to c o n t r o l NH3 losses by spraying the treated straw with organic acids. They obtained a markedly improved nitrogen-retention in the straw and nitrogen d i g e s t i b i l i t y i n sheep with - 62 -this alkali-acid treatement. Methods such as this will undoubtedly be researched using grain in the near future, but one has to doubt both its role as a preservative, since the pH effect will tend to be neutralized, and the economics of the treatment. 4.3.3 Treating and Storing Chemically Preserved Grains The most common method to chemically treat large volumes of high-moisture grain is by use of a spray nozzle connected to the auger delivering the treated grain to storage (Oones et al. 1972; Hyde and Burrel 1973; Bothast et al. 1975; Orskov et al. 1979). Other methods of application involve mixer-wagons, mixing by shovel and simply sprinkling the treatment on the surface of the grain (Nelson et al. 1973; Tait 1979; Ingalls et al. 1974). Ideally, the grain should be treated just prior to entering the storage vessel in order to minimize contact with machinery and prevent corrosion. Acid-treated high-moisture grains cause extensive rusting of galvanized steel bins within one year and reduce its life from 30 to 3 years (Holmes et al. 1972). Aluminized steel bins will last approximately five times as long as galvanized steel under the same conditions (R. Cairns, United Agri Systems, pers. comm.). Steel silos with a vitreous-enamel finish are used successfully for storing high-moisture grain. This finish protects the steel from corrosion by silage acids (Hyde 1974) and, most likely, chemicals from treated grain. Other protective coating materials (chlorinated rubber, urethanes polyolefins, polyethylene or polyvinyl chloride) have been examined and reviewed by Oones et al. (1974). Combinations of coatings often provide - 63 -the best p r o t e c t i o n . However, acid and a l k a l i (at least NaOH) treated grains can be stored anaerobically almost anywhere; on barn f l o o r s , i n bunker s i l o s , i n wooden bins, i n butyl rubber bags, in p l a s t i c sacks, etc. ( K r a l l 1972; Hyde 1974; Oones et a l . 1974; Bothast et a l . 1975; Orskov et al.'1979), and therefore, the employment of s t e e l storage structures i s not necessary. Moisture migration, as in NH3-treated grain, creates a problem in acid-treated grain too. The accumulation of moisture near the surface of the grain tends to d i l u t e the acid concentration and 'hot spots' or spontaneous heating can develop ( T r i s v y a t s k i i 1969). Browning i n NaOH-treated grains i s observed to a greater extent than in NH3-treated grains, as the a l k a l i n e conditions are generally more severe with NaOH. E a r l i e r reports by Feeney (1975) and De Groot et a l . (1976) made note of the browning e f f e c t of NaOH on grain, but i n more recent ruminant studies (Orskov et a l . 1977; 1978; 1979; 1980; 1981; Anderson et a l . 1981; Berger et a l . 1981) t h i s t o p i c has apparently gone unmentioned. Browning has also not been reported i n acid-treated grains. Impared grain flow (bridging) has been observed i n a l k a l i - t r e a t e d grains ( P e p l i n s k i et a l . 1978; Anderson et a l . 1981) and in grains stored over 30% moisture ( K r a l l 1972). Moisture migration may lead to bridging or caking of high-moisture grains for reasons mentioned e a r l i e r . Consequently, P e p l i n s k i et a l . (1978) suggested an in bin s t i r r i n g device to prevent heat gradients from developing and the r e s u l t i n g migration of moisture which impedes grain flow. It i s e s s e n t i a l to remember that the materials used for t r e a t i n g high-moisture grains are ei t h e r acids or very strong a l k a l i s . In the - 64 -concentrated form, these chemicals are t o x i c , corrosive, v o l a t i l e ( e s p e c i a l l y NH3) and some are flammable. When handling these chemicals gloves and goggles should be worn as well as an aspirator mask when handling NH3 (Ministry of Agriculture, F i s h e r i e s and Food 1970). - 65 -MATERIALS AND METHODS 1 . In t roduct ion The experimental work was conducted in three phases. Each phase u t i l i z e d a separate batch of barley which was treated in various ways and evaluated i n _iri vivo experiments with monogastrics and ruminants, the l a t t e r in phases II and III only. Phase I used high-moisture barley from the Peace River country which was harvested in 1980, stored over the winter and evaluated in rats and pigs in the spring of 1981. The second phase u t i l i z e d barley from Lacombe, Alberta, which was harvested in 1981 in two stages, as high-moisture grain and as dry grain. In addition to the grain, the straw was harvested during both stages. Both the barley-grain and straw were evaluated, separately, in sheep while the grain only was evaluated in rats, during the 1981 - 1982 winter. In phase I I I , whole dry-barley of an unknown o r i g i n was purchased l o c a l l y and reconstituted and preserved in several ways. It was again evaluated in both sheep and rats in the spring of 1982. In a l l of the experiments, attention was focused mainly on apparent dry matter, organic matter, f i b r e and nitrogen d i g e s t i b i l i t y c o e f f i c i e n t s and nitrogen u t i l i z a t i o n of the various barley treatments by the animals. 2. Phase I In l a t e September 1980, twenty tonnes of high-moisture barley (HMB) (83% DM) arrived by transport at U.B.C. approximately 48 hours a f t e r i t had been harvested at a reported 81% DM, by the person in Peace River in charge of harvesting. O r i g i n a l l y , barley with a moisture - 66 -content of 21% was requested, since i t was learned that barley of t h i s nature would be most acceptable to Peace River farmers in terms of the combining and handling c h a r a c t e r i s t i c s of the g r a i n . However, the dry-down rate of standing grain Can be as high as 4% per day (Mederick et a l . 1982) and, consequently, i t i s d i f f i c u l t to harvest high-moisture grain exactly at a predetermined moisture content. Nevertheless, the Peace River HMB was divided into four five-tonne treatments c o n s i s t i n g of: (1) Anaerobic environment - the HMB was placed d i r e c t l y into storage vessels which were then sealed. (2) A l k a l i - a 32% w/w s o l u t i o n of sodium hydroxide (NaOH) and water was mixed i n s t a i n l e s s s t e e l containers and allowed to cool for several days before being added to the HMB, in 150 Kg batches, and mixed thoroughly for 5-7 minutes in a v e r t i c a l feed mixer. The r e s u l t i n g concentration of NaOH in the HMB was 32 g/Kg ( a i r dry b a s i s ) , as recommended by Orskov et a l . (1980), and the moisture content was 21.8%. (3) Acid - a 1% mixture of 60:40 a c e t i c -propionic acid (Chemstor, Celanese Canada Ltd., Edmonton, Alberta) was added to the HMB and mixed thoroughly for 5-7 minutes in a v e r t i c a l feed mixer. F i n a l moisture content was 17.2% moisture. (4) Dried - the HMB was commercially dried to 13.3% moisture at 82°C in a 375-Mathews grain d r i e r at a rate of 8 tonnes per hour. Each treatment was divided between two f i b r e form c y l i n d e r s (153 cm diameter, 183 cm high) which were l i n e d inside and outside with black polyethylene (0.15 mm thickness) bags. The inside bag contained the grain and the outside bag protected the f i b r e form c y l i n d e r and the grain from p r e c i p i t a t i o n , as the containers were not stored under a roof. For treatments 2 to 4, the bags were sealed s u f f i c i e n t l y only to - 67 -prevent the entry of free-water and not a i r into the g r a i n . However, treatment 1 was made hermetic by placing a p a i l with a layer of polyurethane foam on the outside at the top-centre of the container and tying the open end of the in s i d e bag securely around the bucket. Two other a l t e r n a t i v e methods of sealing were rejected as being unsuitable -tw i s t i n g and tying may have allowed entry of a i r , while heat sealing would have made frequent access inconvenient. P r i o r to f i l l i n g , one thermocouple was placed in the centre of each container for subsequent temperature monitoring. The storage containers were placed on wooden p a l l e t s and stored on a well drained asphalt surface without cover. A f t e r 9 months of storage, each of the four types of preserved barley were evaluted in a d i g e s t i b i l i t y t r i a l with pigs and a nitrogen balance t r i a l with r a t s . 2.1 I n i t i a l Experiments I n i t i a l l y , both feeding and d i g e s t i b i l i t y t r i a l s with Dorset Horn lambs were to be conducted, but poor p a l a t a b i l i t y t r i a l s with dried and acid-treated HMB, fed as the sole d i e t , forced these t r i a l s to be c a n c e l l e d . However, p a l a t a b i l i t y was not a problem with pigs, and l a t e r , a nitrogen balance and d i g e s t i b i l i t y study' with catheterized Large White X Large White/Landrace g i l t s (30-35 Kg) was commenced, only to be prematurely terminated. Infections r e s u l t i n g from the urinary catheters caused some blockage of the urine and obvious discomfort to the pigs. The c o l l e c t i o n s obtained from t h i s t r i a l were chemically analyzed, but due to the low number of r e p l i c a t i o n s (2), the r e s u l t s obtained were not taken f u r t h e r . However, some v a l i d observations were - 68 -made which would aid in conducting future experiements. 2.2 Experiment 1 (PI-E1): D i g e s t i b i l i t y T r i a l with Pigs Fed Barley from Peace River A completely randomized design was incorporated in which six treatments were evaluated with 12 Large White X Large White/ Landrace barrows of body weight 30-35 kg. Three r e p l i c a t i o n s for each animal were obtained to give six observations for each treatment. The animals were i n d i v i d u a l l y penned for ten days and then placed in d i g e s t i b i l i t y crates, of the S h i n f i e l d design (Frape et a l . 1968a), for two days during the adaption period. Three consecutive five-day c o l l e c t i o n periods followed for each block of pigs in which a complete f e c a l c o l l e c t i o n technique was used. Total d a i l y feces for each animal was weighed, mixed and a 200 g subsample bagged and frozen at -20°C for future a n a l y s i s . Urine was not c o l l e c t e d . The barrows remained in the crates for 17 days in a temperature controlled metabolism room and were weighed before and after the t r i a l . One hundred and f i f t y kilograms of each of the four types of preserved grain were processed in a Peerless, 20 cm, f l u t e d r o l l e r m i l l . Both types of chemically preserved HMB were also fed whole, making a t o t a l of six treatments. A l l batches of grain were stored in several 40 1 p l a s i t i c containers with loose f i t t i n g l i d s in a dry feed room during the experiment. A vitamin-mineral mixture (Table 7) was added to i n d i v i d u a l l y weighed di e t s as a supplement. Due to the high sodium concentrations in the a l k a l i - t r e a t e d HMB, the iodized sodium c h l o r i d e i n the supplement was replaced by iodized potassium c h l o r i d e for t h i s d i e t . The d a i l y feeding procedure involved feeding twice - 69 -Table 7. Vitamins and minerals added to barley at a l e v e l of 3 g/100 g f i n a l diet (DM basis) for pigs in t r i a l PI-E1. Component Percentage of Dry Total Diet Sodium chloride ( i o d i z e d ) * 0.5 Limestone 1.0 Dicalcium phosphate 1.0 Vitamin-trace mineral mix# 0.5 *In the a l k a l i treatment, the sodium chloride was replaced by 0.64% potassium chloride premixed with 0.01 g KI per 100 g KC1. ^Vitamin-trace mineral mixture (/kg) Vitamin A 617,000 I.U.: Vitamin D3 88,100 I.U.; Vitamin E 2200 I.U.; Vitamin B12 4 mg; niacin 2.2 g; r i b o f l a v i n 0.57 g; DL calcium pantothenate (45%) 4.4 g: manganese sulphate 8.8 g; zinc sulphate 61 g; sodium se l e n i t e 42 mg, B.H.T. 100 g. d a i l y , once in the morning at 8:00 and again at 3:00 p.m. Throughout the experiment, feed intake was r e s t r i c t e d to 1.25 kg DM/animal/day, which was corrected for s p i l l a g e before the c a l c u l a t i o n of d i g e s t i b i l i t y c o e f f i c i e n t s . The s p i l l a g e was determined by washing the c o l l e c t i o n tray, under the feeder, into a bucket covered with a 2 mm screen mesh. The residue remaining on the screen was dried, weighed and then m u l t i p l i e d by a factor to determine the t o t a l s p i l l a g e . This factor was predetermined by placing a known amount of feed on the screen and wash-ing i t with running water for several minutes. The residue was dried and weighed and the r a t i o between the residue and the known amount of feed was ca l c u l a t e d . The d i g e s t i b i l i t y crates were equipped with auto-matic water nipples which supplied fresh water to the animals throughout the experiment. Apparent d i g e s t i b i l i t y of dry matter, neutral detergent - 70 -f i b r e and protein was measured. True protein d i g e s t i b i l i t y was also c a l c u l a t e d using a c o r r e c t i o n factor for metabolic f e c a l - n i t r o g e n of 0.1 g N/100 g DM consumed (Maynard and L o o s l i 1969). 2.3 Experiment 2 (PI-E2): Nitrogen Balance T r i a l with Rats Fed Barley from Peace River Twenty-five white Woodlyn Wistar male rats of average weight 70 g were segregated in a completely randomized design with f i v e i n d i v i d u a l l y fed r ats a l l o c a t e d to each of the four treatments of HMB (anaerobic, a l k a l i , acid, dried) and a c o n t r o l d i e t . The barley treatments were p a r t i a l l y dried in a forced dr a f t oven at 40°C overnight to prevent moulding of the anaerobic barley and to f a c i l i t a t e grinding of the damp treatments through a 1 mm screen. The d i e t s were balanced with a nitrogen-free mixture to form a d i e t containing 1.5 g N/100 g DM a f t e r f o r t i f i c a t i o n with minerals and vitamins (Table 8). The c o n t r o l d i e t was s i m i l a r in content only, the nitrogen in the d i e t was replaced by a casein plus L-methionine (1 g/100 g casein) mixture instead of barley. The d i e t s were thoroughly mixed for f i v e minutes i n a pharmaceutical mixer and r e f r i g e r a t e d (2°C), not longer than a week, u n t i l used. At the s t a r t of the t r i a l , the d i e t s were i n d i v i d u a l l y packaged in 10 g DM q u a n t i t i e s with aluminium f o i l and stored at room tempera-ture. Each rat was fed one package per day. An adaption period of four days was followed by a complete c o l l e c t i o n period of f i v e days. During the c o l l e c t i o n period, a feces-urine separtion device was placed under the cage. This device was comprised of an acetate funnel placed on a 45° angle and l i n e d with a p l a s t i c net for separating the feces from the - 71 -Table 8. Composition of mixture added to die t s for rats in t r i a l s PI-E2, PII-E3 and PIII-E2. N-Free Mixture Potato starch (autoclaved then ground) Cane sugar C e l l u l o s e powder Soybean o i l Mineral Mixture Calcium carbonate CaC0 3 Calcium c i t r a t e C a 3 ( C 6 H 5 0 7 ) 2 Calcium hydrogen phosphate (^HPO^, 2H 20 Potassium hydrogen phosphate, secondary Potassium chloride KC1 Sodium Chloride NaCl Magnesium sulphate MgS0\ Magnesium carbonate MgC03 Ammonium f e r r i c i t r a t e Manganese sulphate MnS04*H20 Cupric sulphate CuS0i+*5H 20 Potassium iodide KI Sodium f l u o r i d e NaF Aluminum ammonium sulphate Al 2 ( S O L t ) 3 (N Vitamin Mixture 10663AIN Vitamin Mixture 76 - American I n s t i t u t e of N u t r i t i o n . American I n s t i t u t e of N u t r i t i o n , L t r . Communication March 15, 1977. Mineral and vitamin mixtures were added at 4 0 and 8 g (A.D. ba s i s ) , r espectively, per kg of each d i e t . urine. The urine was funnelled and f i l t e r e d through glass-wood into 5 0 0 ml f l a s k s containing 50 ml 5% H 2 S 0 i t . The feces were c o l l e c t e d d a i l y from p l a s t i c bags, attached to the p l a s t i c net, and frozen at - 2 0°C for future a n a l y s i s . At the end of the c o l l e c t i o n period, the urine f l a s k s were c o l l e c t e d after the acetate funnels and p l a s t i c nets were thoroughly rinsed with 5% c i t r i c acid. The i n d i v i d u a l urines were then made upto 2 5 0 ml with d i s t i l l e d water in volumetric f l a s k s and then 80.67 g 8.92 5.2 5.2 IH i +) 2*2H 20 68.6 g 308.3 112.8 218.8 124.7 77.1 38.3 35.2 15.3 0.201 0.078 0.041 0.507 0.090 - 72 -stored at 2°C f o r not more than three days u n t i l analyzed. The r a t s were housed i n i n d i v i d u a l p l e x i g l a s s cages i n a humidity and temperature c o n t r o l l e d room, ranging from 55 to 65% r e l a t i v e humidity and 24 to 27°C. Free access to water was permitted and the room had l i g h t twelve hours per day. The equipment and methods were according to Eggum (1973). True p r o t e i n d i g e s t i b i l i t y (TD), b i o l o g i c a l value (BV), net p r o t e i n u t i l i z a t i o n (NPU = TD x BV) and apparent dry matter d i g e s t i b i l i t y were measured. TD was c o r r e c t e d f o r metabolic f e c a l - N by s u b t r a c t i n g 102 mg N from the f i v e day fecal-N output. When c a l c u l a t i n g BV, urinary-N was c o r r e c t e d f o r endogenous-N by s u b t r a c t i n g 76 mg N from the f i v e day urinary-N output. The c o r r e c t i o n values were those estimated by Eggum (1973). 3. Phase I I Experimental barley ( v a r i e t y g a i t ) and straw a r r i v e d at U.B.C. i n September 1981, from the A l b e r t a A g r i c u l t u r e F i e l d Crops Research Branch, Lacombe, A l b e r t a . The shipment contained barley and straw with the f o l l o w i n g treatments and q u a n t i t i e s : (1) High-moisture barley (HMB) (67% DM) - swathed then immediately combined and sealed i n two p l a s t i c l i n e d 203 1 drums with t i g h t - f i t t i n g l i d s , (2) A r t i f i c i a l l y d r i e d barley (ADB) (89% DM) - d r i e d from HMB (67% DM) i n gas f i r e d d r i e r s and stored i n two unlined 203 1 drums, (3) F i e l d - d r i e d b a r l e y (FDB) (89% DM) - harvested under conventional c o n d i t i o n s and transported i n a one-tonne f e r t i l i z e r bag, (4) High-moisture straw (HMS) - straw harvested from HMB was sun-cured f o r three weeks to 91% DM, chopped and d e l i v e r e d i n two one-tonne f e r t i l i z e r bags, and (5) F i e l d - d r i e d straw - 73 -(FDS) (89% DM) - straw harvested from FDB, a quantity s i m i l a r to that of HMS. The barley was grown on a 30 x 180 m plot, with even numbered swaths taken for HMB and ADB, and odd numbered swaths taken three weeks la t e r for FDB. After combining the FDB, both the HMS and FDS were chopped and bagged. The dry matter values quoted are those that were assessed on a r r i v a l at U.B.C, these values varied throughout the experiments. Upon a r r i v a l at U.B.C, the HMB was inspected and a cake of mouldy grain approximately 15 cm thick was discovered on the surface of both drums. The spoilage had developed as a result of being poorly sealed, allowing for aerobic conditions. The spoiled material was removed and the drums were purged with inert nitrogen gas (N 2) according to the method of S e r a f i n i et a l . (1980) and resealed to prevent further microbial damage. The materials were stored in a clean dry room maintained at approximately 10-15°C throughout the storage period. No further spoilage in the treatments occurred. The barley grain was contaminated with straw and chaff, and consequently, the grain was analyzed to determine the v a r i a t i o n i n botanical composition between treatments (Table 9). Representative 1 kg samples of each treatment were c o l l e c t e d and p a r t i a l l y dried to f a c i l i t a t e separation of the contaminating material from the kernels. The samples were placed on a smooth table top and quartered. One quarter of the barley was selected and placed i n a 2 mm (No. 10 Canadian Standard) sieve. Fines were co l l e c t e d after several minutes of vigorous shaking. The large non-grain p a r t i c l e s (chaff, straw, etc.) that remained were - 74 -Table 9. Botanical composition of barley from Lacombe (Phase II) Type of Barley Composition — (%DMB) F i e l d A r t i f i c i a l l y Dry Dried High-Moisture Reconstituted Grain 97.78 97.93 96.43 97.84 Fines* 1.24 1.43 2.78 1.28 Chaff & Straw** 0.98 0.64 0.79 0.88 Total Fines, Chaff & Straw 2.22 2.07 3.57 2.16 * P a r t i c l e s that passed through a 2 mm sieve. **Materials that did not pass through a 2 mm sieve. systematically removed from the barley with forceps. The proportions were dried and weighed and t o t a l composition was calculated on a dry matter basis. Cleaning the various batches before feeding was not attempted since aerating the HMB would not have been compatible with the experimental design. 3.1 Experiment 1 (PII-E1); D i g e s t i b i l i t y T r i a l with Sheep Fed Barley-Straw from Lacombe Twelve Dorset Horn ewe lambs of body weight 37-43 Kg were incorporated into a completely randomized design in which high-moisture straw (HMS), sun-cured from HM barley, and f i e l d dried straw (FDS), from FD barley, were compared. In order to obtain a more uniform product, the straw was rechopped in a garden mulcher, without a screen, to a length not exceeding 7 cm. It was hoped that shorter straw would r e s u l t in less sorting and s p i l l i n g during feeding and help promote intake and produce more consistent r e s u l t s . The straw was fed to appetite twice d a i l y at 8:30 a.m. and 4:30 p.m. and was supplemented only with a trace mineralized s a l t mixture (10 g/ewe/day) (Table 10). Weighbacks were - 75 -taken p r i o r to the morning feeding and were d r i e d , weighed and stored in p l a s t i c bags for a n a l y s i s . The ewes were i n d i v i d u a l l y penned during a Table 10. Trace mineralized s a l t with selenium supplement* for sheep in t r i a l s PII-E1,2 and PIII-E1 .** Composition of Supplement Salt (NaCl) 96.5 % Zinc .40 Iron .16 Manganese .12 Copper .033 Iodine .010 Cobalt .004 Selenium .0025 ^Obtained from Buckerfields Ltd., Vancouver, B.C., Canada. (Reg. No. 22440) The supplement was excluded from the NaOH-treated barley d i e t in t h i s t r i a l . fourteen-day adaption period and were subsequently placed in d i g e s t i b i -l i t y crates for a ten day, complete f e c a l , c o l l e c t i o n period. The feces were c o l l e c t e d d a i l y and dried, weighed and stored for a n a l y s i s . Sheep had.free access to water and iodized s a l t . The apparent d i g e s t i b i l i t y c o e f f i c i e n t s measured were dry matter, organic matter, acid detergent f i b r e and nitrogen. The dry matter of the straw varied from 81 to 86% during the t r i a l . This v a r i a t i o n was due to the very damp c l i m a t i c conditions which p r e v a i l e d . However, dry matter intake was c a l c u l a t e d on a d a i l y basis so the moisture v a r i t i o n was accounted for in a l l c a l c u l a t i o n s . 3.2 Experiment 2 (PII-E2): D i g e s t i b i l i t y and Nitrogen-Retention T r i a l with Sheep Fed Barley-Grain from Lacombe A f t e r four months of storage, an unbalanced randomized block - 76 -design, including six Dorset Horn ewe lambs averaging 40 Kg body weight, was employed to compare four treatments in four blocks. Consequently, each ewe received a l l four treatments. The barley treatments were f i e l d - d r i e d (FDB) (88% DM) a r t i f i c i a l l y dried (ADB) (89% DM), high-moisture (HMB) (56% DM) and reconstituted (RB) (71% DM). The HMB had a much lower dry matter content (56%) than was expected. At time of harvest DM was reported at 67% for HMB which was consistent with measurements that were taken from the top of the drums upon a r r i v a l at U.B.C. However, the moisture content of the grain was s u b s t a n t i a l l y higher a f t e r the four months of storage. Reasons for t h i s low DM content w i l l be discussed further in the r e s u l t s and d i s c u s s i o n . The RB was produced by rewetting 11.4 Kg of FDB i n a 23 1 polyethylene p a i l with 2.84 1 of water. The p a i l was sealed with a locking, a i r t i g h t l i d and inverted d a i l y for a week to ensure even and complete absorption of water by the kernels. Twelve p a i l s of RB (140 Kg) was prepared and stored for at l e a s t three weeks before being fed, as suggested by K r a l l (1972). To prevent subsequent spoilage and improve a c c e s s i b i l i t y , the HMB was t r a n s f e r r e d to polyethylene p a i l s , purged with N 2 and sealed with locking, a i r t i g h t l i d s , the same as RB. FDB and ADB were stored in 203 1 drums with loose f i t t i n g l i d s during the t r i a l . The sheep were i n i t i a l l y adapted to the barley for fourteen days u n t i l a steady l e v e l of intake (600-700 g DM/ewe/day) was achieved for each animal. Subsequent adaption periods i n t h i s t r i a l were seven days. Feed was i n d i v i d u a l l y weighed d a i l y with the animals r e c e i v i n g the rations twice d a i l y at 7:30 a.m. and 3:00 p.m. The HMB and RB - 77 -treatments were purged with N 2 before the p a i l s were closed a f t e r each d a i l y weighing. The d i e t s were supplemented with trace mineralized s a l t (10g/ewe/day) (Table 10) and a g r i c u l t u r a l grade limestone (5 g/ewe/day). After the adaption period a seven day c o l l e c t i o n period followed, in which t o t a l feces were c o l l e c t e d . T o t a l urine was c o l l e c -ted f or the f i n a l f i v e days. The urine was f i l t e r e d through clean gauze, to prevent f e c a l contamination, into a polyethylene vessel containing 50 ml s u l f u r i c acid (50%\/\) during c o l l e c t i o n . At the end of each c o l l e c t i o n day, the urine was weighed and mixed, and a 100 ml subsample was taken from each animal and stored at 2°C. Following the completion of each block, the urine samples for each treatment were pooled and analyzed the same day. Feces were handled in the same way as discussed previously (PII-E1). Throughout the t r i a l , free choice to water and iodized s a l t was allowed. Measurements included apparent d i g e s t i b i l i t y of dry matter, organic matter, acid detergent f i b r e and nitrogen as well as nitrogen r e t e n t i o n . 3.3 Experiment 3 (PII-E3); Nitrogen Balance T r i a l with Rats Fed Barley from Lacombe An experiment designed and executed as described in PI-E2, was conducted to compare f i v e d i e t s including grain which had been stored f o r two months. The barley, before being ground and included in the formulated d i e t s , consisted of: (1) FDB (89.7% DM), (2) ADB (89.8% DM), both d i r e c t l y from storage, (3) HMB-top (HMBT) (85.9% DM) -subsamples of HMB from the top 1/3 of both drums were combined and fre e z e - d r i e d from 74.7% DM, (4) HMB-bottom (HMBB) (91.5% DM) -subsamples of HMB from the bottom 1/3 of both drums were combined and - 78 -freeze-dried from 64.8% DM, (5) Control - same as described in PI-E2. Freeze-drying was employed to reduce the moisture content of the grain while preventing losses of v o l a t i l e compounds. Karel et a l . (1975) reported no reduction in retained v o l a t i l e s from f i n e l y ground materials evacuated at room temperature and freeze-dried for up to thirte e n hours. Also, Gones and Larsen (1974) concluded that in v i t r o analyses or other biochemical determinations should be conducted on ensiled products that have been either freeze-dried or oven-dried at 40°C. These reports suggest that freeze-drying i s a superior method of drying HM grain as compared to oven-drying at temperatures > 40°C, in order to prevent dry matter and n u t r i t i o n a l losses. 4. Phase III One tonne of sacked, whole barley (88% DM) was purchased from a commercial feed supplier. From t h i s barley, 600 Kg was divided into four treatments and stored in si x t y 23 1 polyethylene p a i l s with locking a i r t i g h t l i d s . In phase II - experiment 2, reconstituted barley stored in a s i m i l a r manner produced a p o s i t i v e pressure causing the p a i l to bulge. Consequently, a pressure release value was designed and f i t t e d on the l i d s for t h i s phase of experiments. A 0.78 cm hole was bored through the l i d in which a polypropylene tubing connector was inserted and joined to a 10 cm length of latex tubing (7.9 mm I.D. x 3.2 mm w a l l ) . S i l i c a gel was used to seal the j o i n t s . The open end of the tube was sealed with a screw clamp and a small s l i t was cut in the tube to allow excess pressure in the p a i l to be relieved while maintaining anaerobic conditions. A l l treatments were prepared by r e c o n s t i t u t i n g 10 Kg of barley - 79 -with 2.61 1 of water per p a i l . The p a i l s were shaken and inverted daily for a week to promote even and complete absorption of water by the kernels. The p a i l s were then divided into four treatments with f i f t e e n p a i l s per treatment. The treatments consisted of: (1) Reconstituted barley (RB) (70.0% DM) - the barley was reconstituted and stored for over 21 days before being fed, as noted in phase II - experiment 2, (2) Sodium hydroxide treated RB (NaOH-RB) (65.1% DM) - a 30% w/w solution of NaOH was prepared as described i n phase I and mixed thoroughly with RB, a p a i l at a time, i n a Hobart planetary mixer. A f i n a l concentration of 30 g NaOH/Kg RB (an dry basis) was obtained. The treated barley was then transferred and stored a e r o b i c a l l y in a 203 1 drum lined with p l a s t i c . (3 and 4) Ammoniated RB (1 and 3% NH3-RB) (69.8 and 68.4% DM) - anhydrous (gaseous) NH3 was injected to a concentration of 1 and 3% w/w ( a i r dry b a s i s ) . NH3 application was accomplished by placing the p a i l upside down, to help f a c i l i t a t e d i f f u s i o n of the gas through the grain, on a 25 Kg Avery scale accurate to 1.0 g. The NH3 was injected through the valve u n t i l the desired weight increase was reached. In a preliminary study, a p a i l f i l l e d with RB and equiped with two valves was used to test the ammoniation procedure. On one valve a small party balloon was fixed and NH3 was injected through the second valve. The purpose of the balloon was to indicate the rate of absorption of NH3 by the grain. For example, i f NH3 was injected faster than i t s absorption rate, a p o s i t i v e pressure in the p a i l would cause the balloon to i n f l a t e i n d i c a t i n g that the rate of i n j e c t i o n should be reduced. This method worked well; however, i t was concluded that the rate of NH3 i n j e c t i o n s could be safely c o n t r o l l e d by observing the - 80 -response of the l i d to pressure changes in the p a i l . The centre of the l i d would expand when the i n j e c t i o n rate exceeded the absorption rate of N H 3 , therefore, e l i m i n a t i n g the need of a balloon and a second valve. Even with a p o s i t i v e pressure in the p a i l s , losses of NH3 were not detected by e i t h e r changes in weight or by i t s d i s t i n c t odour. Furthermore, during NH3 a p p l i c a t i o n in both the p a i l s and j a r s , a negative pressure developed in s i d e the sealed containers i f the rate of i n j e c t i o n was too low. This was f i r s t observed when the balloon on the safety valve would tend to collapse rather than i n f l a t e when NH3 was i n j e c t e d at a slow rate. Later, with the p a i l s , a f t e r NH3 a p p l i c a t i o n (1 or 3%) was complete several p a i l s began to c o l l a p s e as a r e s u l t of the pressure d i f f e r e n t i a l . Consequently, a i r was admitted to the p a i l to equalize the pressure and prevent further d i s t o r t i o n . While applying the NH3, the outside of the NH 3-cylinder became frosted and condensation was observed in s i d e the glass j a r s . These factors i n d i c a t e that the intergranular atmosphere was displaced by the NH3 r e s u l t i n g in the negative pressure. Montgomery et a l . (1980) reported f r o s t i n g on the auger near the point of i n j e c t i o n and condensation and heating further along the auger as anhydrous-NH3 was added to corn. However, in the present t r i a l , heating was only noted near the point of i n j e c t i o n by touch. Due to the r e s u l t i n g negative pressure during NH3 a p p l i c a t i o n , losses of NH3 were c e r t a i n l y not experienced. The a l k a l i treatments were stored for not l e s s than fourteen days p r i o r to feeding. Orskov et a l . (1981 a) suggested s t o r i n g NaOH-treated grain for at l e a s t one week before feeding in order for near complete conversion of hydroxyl ions to carbonate to take place. It was also - 81 -f e l t that more NH3 may become fi x e d over time and better simulate on farm conditions, i f the treated grains were stored for at least fourteen days before feeding. 4.1 Experiment 1 (PIII-E1); D i g e s t i b i l i t y and Nitrogen-Retention T r i a l with Sheep Fed Reconstituted,  A l k a l i - T r e a t e d Barley Twelve Dorset Horn ewe lambs, ranging i n body weight from 35-45 Kg were employed i n a completely randomized design to obtain six observations for each of the four treatments (RB, NaOH-RB, 1 and 3% N H 3-RB). The ewes were s t a b i l i z e d on a steady l e v e l of intake ranging. from approximately 600 to 700 g DM per day of whole treated RB. Feeding and c o l l e c t i o n techniques were i d e n t i c a l to those described i n PII-E2, with only two exceptions. A f t e r the NH3~treated barley was weighed into i n d i v i d u a l p l a s t i c bags for each feeding, the bag was l e f t open for one day p r i o r to feeding to allow the f r e e - N H 3 concentration to subside. I t was observed early i n the adaption period, that NH3~treated barley fed d i r e c t l y from the p a i l was poorly accepted, but a f t e r only one day of aeration both of the NH 3 tretments were consumed without h e s i t a t i o n . Also, the ewes on NaOH-treated barley did not receive trace mineralized s a l t due to the high sodium concentration already present i n the treated barley. In several papers by Orskov and co-workers, sodium c h l o r i d e (NaCl) was apparently replaced by calcium c h l o r i d e (CaCl); however, Anderson et a l . (1981) did not delete trace mineralized s a l t from NaOH rations for ruminants. Consequently, due to the d r a s t i c increase i n urine production observed previously i n animals on NaOH-treated barley and the high sodium concentration i n the feed, i t - 82 -was decided to remove the trace mineralized s a l t from the r a t i o n . Under normal conditions, c h l o r i n e (CI) i s excreted at h a l f the rate of sodium (Maynard and L o o s l i 1969) and because the ewes were only on the NaOH-treated barley for two weeks, a d d i t i o n a l CI was not substituted f o r that l o s t by removing the trace mineralized s a l t from the d i e t . However, iodized s a l t was supplied in the block form for a l l treatments, i n c l u d i n g NaOH, throughout the experiment. Through a s e r i e s of chemical analyses and t h e o r e t i c a l c a l c u l a t i o n s , c o r r e c t i o n f a c t o r s were determined for the oven-dried NH3 treatments that would estimate more accurately the actual dry matter content and, u l t i m a t e l y , the d i g e s t i b i l i t y c o e f f i c i e n t s . By analyzing the nitrogen content of the NH3-RB (1% and 3% treatments) before and a f t e r oven-drying, the d i f f e r e n c e observed in nitrogen content explained much of the v a r i a t i o n in dry matter content when compared to RB. The nitrogen l o s t by oven-drying the 1 and 3% NH3-RB was 0.504 and 2.126%, r e s p e c t i v e l y . These values were added to the oven DM content of the NH3-RB p r i o r to c a l c u l a t i n g the d i g e s t i b i l i t y c o e f f i c i e n t s . For example, the oven dry matter content of 3% NH3-RB was approximately 67%, but with the c o r r e c t i o n factor (2.126%) added, the DM content of the NH3-RB was increased to over 69% which was very close to RB at 70% DM. Consequently, losses of v o l a t i l e NH3 during oven drying are accounted for r e s u l t i n g in more accurate DM determinations of NH3-RB. For a n a l y t i c a l purposes, the d i g e s t i b i l i t y c o e f f i c i e n t s were s t a t i s t i c a l l y analyzed with and without the c o r r e c t i o n factors applied. - 83 -4.2. Experiment 2 (PIII-E2): Nitrogen Balance T r i a l with Rats Fed Reconstituted, Alkali-Treated Barley. As i n PI-E2, a rat t r i a l was conducted to compare f i v e diets based on barley treated in various ways. The barley in the diets consisted of: (1) Untreated dry barley (DB) (89.0% DM) - a sample of dry barley, of the same or i g i n as the other treatments, was taken d i r e c t l y from the o r i g i n a l sacks, (2) RB (92.6% DM), (3) NaOH-RB (95.5% DM)- samples for both treatments (2) and (3) were taken from storage and freeze-dried from 70.0 and 65.2% DM, respectively, (4) 1% NH3-RB (93.7% DM) and (5) 3% NH3-RB (93.8% DM)-samples for both 1 and 3% NH3-RB were taken from p a i l s and freeze-dried from 69.2 and 67.5% DM, respectively. A l l treatments were ground through a 1 mm screen. The NH3 treatments were then spread in thin layers in large trays and aerated at 20°C for nine days in a forced-draft oven. Aerating the dry, ground NH3-RB was intended to s t a b i l i z e the nitrogen content of the grain before i t was incorporated into the rat d i e t s . Nitrogen analyses were carried out on the barley throughout the nine days u n t i l i t was determined that further N losses due to NH3 v o l a t i l i z a t i o n would be very small. However, to monitor the treatments further, samples of both 1 and 3% NH3-RB were analyzed for nitrogen content at day 1 and 9 of the t r i a l so that nitrogen intake by the rats on these treatments could be accurately assessed. The averages of the nitrogen value obtained from day 1 and 9 were used for evaluating the nitrogen u t i l i z a t i o n c o e f f i c i e n t s for treatments four and f i v e . To assess the effect of NH3 on the residual grain nitrogen alone, the remaining NH 3-nitrogen in the barley was subtracted from the t o t a l nitrogen content of the NH3~treated grains. - 84 -The remaining NH3-N in the grains were c a l c u l a t e d by subtracting the nitrogen value of untreated RB from the NH3-treated grains, which were incorporated i n the rat d i e t s . The remaining NH3-N in the grain was also subtracted from urinary-nitrogen to remove the nitrogen from the excretory products contributed by the remaining NH3. The NH3-N was removed from the urine on a somewhat a r b i t r a r y basis, but i t appeared from the feces and urine nitrogen l e v e l s that urine was most greatly a f f e c t e d . The NH3-N l e v e l s determined f or 1 and 3% NH3-RB were 0.019 and 0.049, r e s p e c t i v e l y . The r e s u l t s from the t r i a l were s t a t i s t i c a l l y analyzed both with and without these c o r r e c t i o n values for NH3-N applied. 4.3. Experiment 3 (PIII-E3): NH3-Retention of Reconstituted, Ammoniated Barley One kilogram of dry barley (88% DM) was placed i n each of f i v e 3 1 glass j a r s . Water was added to four of the f i v e j a r s so that the moisture content of the treatments would be 12, 18, 24, 30 and 36%. Aft e r the addition of water, the j a r s were sealed with a i r t i g h t , metal l i d s , each f i t t e d with two valves as described e a r l i e r i n phase I I I . The j a r s were shaken frequently to ensure complete and even r e c o n s t i t u -t i o n and stored for one week p r i o r to ammoniation. NH3 was injected at 30% w/w ( a i r dry basis) i n a l l f i v e treatments. The j a r s were placed on a 5 Kg Avery scale accurate to 1.0 g, and the NH3 was injected u n t i l the desired weight increase was reached. The rate of i n j e c t i o n was monitored by the 'balloon' technique described e a r l i e r i n phase I I I . Once ammoniated, the treatments were stored for another week, and then the j a r s were opened for a n a l y s i s . Immediately upon opening, the - 85 -barley was analyzed for nitrogen content. Subseguent analysis were made on samples taken from thin layers of grain placed in 22 x 22 cm metal pans, following 2, 4, 7 and 40 days of aeration i n an open room. The experiment, with the exception of the a p p l i c a t i o n of NH3, was conducted under laboratory conditions i n a room with an average temperature of approximately 18-19°C. A p p l i c a t i o n procedures took place out-of-doors in order to safeguard against p o t e n t i a l hazards of anhydrous -NH3. 5. Chemical Analyses 5.1 Nitrogen: Nitrogen contents of dietary components, d i e t s , feces and urine were determined by the macro-Kjeldahl method (A.O.A.C. 1980). Feces from sheep were analyzed in the dry form, but pig and rat feces were analyzed i n the wet form. A mixture of approximately 1:4 feces: d i s t i l l e d water was blended i n a Polytron blender (Brinkmann Instru-ments) to a homogenous s l u r r y from which about 10 g samples of wet material were analyzed i n d u p l i c a t e . Urine was analyzed by t r a n s f e r r i n g exactly 10 ml into the kj e l d a h l f l a s k . Sealed ammoniated barley was analyzed immediately upon upening by quickly placing 5 g whole barley d i r e c t l y into a macro-Kjeldahl f l a s k containing 50 ml concentrated H2S0i+. These samples were analyzed in t r i p l i c a t e . A l l other feed samples were analyzed in the dry form. 5.2 Moisture: Moisture determinations of sheep feces and most feeds for dry matter d i g e s t i b i l i t y c o e f f i c i e n t s were determined by drying the samples - 86 -i n a forced d r a f t oven at 90°C for 48 h. However, HMB in phase II was dried to a constant weight i n a Labconco Freeze Drier-18 at 7y Hg, "60°C for 72 h. Barley treatments i n PIII-E2 were p a r t i a l l y freeze-dried for 24 h. A l l other moisture determinations were made by drying samples at 105°C i n a forced d r a f t oven overnight as described by A.O.A.C. (1980). 5.3 Acid and Neutral Detergent Fib r e ; Acid detergent f i b r e (ADF) and neutral detergent f i b r e (NDF) were determined according to the method of Waldern (1971). 5.4 Ash; Ash contents of the feeds and feces were determined by charring samples i n aluminum dishes, which were then placed i n a muffle furnace at 450°C f o r 15 hours. 6. S t a t i s t i c a l Analyses A l l r e s u l t s were subjected to analysis of variance using the BMD:10V program ( B j e r r i n g et a l . 1975) incorporating a comparison of means using the Student Newman Keul's t e s t . - 87 -RESULTS AND DISCUSSION 1. Phase I 1.1 Core Temperatures of Barley from Peace River Temperature was recorded i n a l l treatments: (1) anaerobic, (2) a l k a l i , (3) acid and (4) dried - for the f i r s t three months of storage (Figure 2). The i n i t i a l l y high temperatures of the chemical treatements ( a c i d and a l k a l i ) , would have been contributed to by heat produced from chemical reactions. These r i s e s i n temperature above the anaerobic barley were approximately 5 and 10°C for the acid and a l k a l i , respect-i v e l y . Recent reports on NaOH-treated barley have not mentioned chemical heating. However, P e p l i n s k i et a l . (1978) recorded s i m i l a r findings of self-induced heating in ammoniated corn which increased the grain temperature to 39°C, an increase of 19°C. Lancaster et a l . (1974) also noted chemical heating in a l k a l i - t r e a t e d corn. Because of t h i s chemically induced heating and high pH, the a l k a l i - t r e a t e d barley turned a reddish-brown in colour in only a few hours due to the browning reac-t i o n (De Groot et a l . 1976 a). The lower r i s e i n temperature i n the acid treatment, than i n the a l k a l i treatment, was due to the fact that the acid was not as strong an agent as the a l k a l i and also the l e v e l of a p p l i c a t i o n was lower (1% acid versus 3.2% NaOH). Nelson et a l . (1973) stored grain sorghum e i t h e r untreated or treated with propionic acid at 16, 21 and 26% moisture. In a l l three cases the temperature of the untreated grain was higher than that of the acid-treated g r a i n . These findi n g s are s i m i l a r to those in the present t r i a l regarding a c i d -treated and anaerobic barley. The temperature r i s e i n the anaerobic TIME (Days) - 89 -treatment would have l i k e l y been higher i f the moisture content had been greater. The i n i t i a l l y high temperatures of the a r t i f i c i a l l y dried barley could be accounted for by r e s i d u a l heat from the drying process. As noted by Sinha (1973), grain has a low thermal conductivity and, as a r e s u l t , r e s i d u a l heat i s slow to d i s s i p a t e from grain bulks. Also, increases i n grain temperature above ambient have been recorded by Muir (1973), who found that f r e s h l y harvested grain may i n i t i a l l y have a temperature up to 7°C higher than atmospheric temperature. These observations help support those i n the present experiment. A s l i g h t r i s e i n temperature occurred in the anaerobic barley i n the early stages of storage. The heat probably resulted from i n i t i a l l y aerobic and l a t e r anaerobic r e s p i r a t i o n that took place i n the g r a i n . Due to the low moisture content (17%) of the anaerobic barley and the r e l a t i v e l y low ambient temperatures, the grain did not appear to ferment. As stated e a r l i e r , K r a l l (1972) suggested adding water to grain under 25% moisture for good fermentation to develop. Hyde and Burrel (1973) also found that many changes associated with a i r t i g h t storage are a function of temperature and may not take place at near freezing temperatures. Therefore, treatment (1) should be classed as only anaerobic or hermetic barley and not as an ensiled product. Maximum temperatures recorded during storage were 16.2°C, 33.8°C, 19.5°C and 24.5°C for treatments 1, 2, 3 and 4, r e s p e c t i v e l y . Ambient temperatures throughout the recorded storage period (October 1 -December 10, 1980) ranged between 2.0 and 13.1°C. The temperature changes for each treatment r e f l e c t e d these values. In general, the findings i l l u s t r a t e d in Figure 2 p a r a l l e l c l o s e l y the temperature pattern i l l u s t r a t e d by Forbes (1965), who stored - 90 -high-moisture (30%) barley i n an a i r t i g h t 10 tonne metal s i l o . Hyde and Oxley (1960) also obtained s i m i l a r r e s u l t s . In both reports, grain temperature of hermetically stored moist grain followed c l o s e l y to the ambient temperature. 1.2 Experiment 1: D i g e s t i b i l i t y T r i a l with Pigs and Experiment 2: Nitrogen Balance T r i a l with Rats Fed Barley  from Peace River A l k a l i - t r e a t e d barley had no s i g n i f i c a n t e f f e c t on either dry matter (DM) or neutral detergent f i b r e (NDF) d i g e s t i b i l i t y in pigs (Table 11), but NaOH s i g n i f i c a n t l y (P < 0.001) increased DM in rats Table 11. D i g e s t i b i l i t y of r o l l e d and whole high-moisture barley preserved in four d i f f e r e n t ways from Peace River determined with pigs in PI-E1. Rolled Whole Anaero-bic A l k a l i Acid Dried A l k a l i Acid SE o1 Mean D i g e s t i b i l i t y (%) 79.6 a* Dry Matter 81.6 a 80.9 a 81.3 a 79.0 a 82.0 a 1.2 Neutral 76 .4 a 80.3 a 77.9 a 70.1 b 77.6 a 79.8 a 1.5 Detergent Fibre Apparent 64.5 a 44.5 b 64.5 a 66.3 a 46.5 b 65.6 a 2.7 Nitrogen True Nitrogen** 70.0 a 50.6 b 70.0 a 72.5 a 52.7 b 70.7 a 2.6 *Means within rows with unlike superscript l e t t e r are s i g n i f i c a n t l y d i f f e r e n t (P < 0.001). ••Correction factor used for metabolic fecal-nitrogen was 0.1 g N/100 g DM consumed (Maynard and L o o s l i , 1969). (Table 12). It was expected that the e f f e c t of NaOH on the fibrous components of the grain would have increased DM d i g e s t i b i l i t y to some degree i n monogastrics as observed i n ruminants by Orskov and Greenhalgh - 91 -(1977) and Orskov et a l . (1980). However, t h i s advantage of the a l k a l i treatment was only evident i n the rat t r i a l and not in the pig t r i a l . Table 12. Dry matter d i g e s t i b i l i t y and protein u t i l i z a t i o n c o e f f i c i e n t s of high moisture barley stored i n four d i f f e r e n t ways from Peace River determined with rats i n PI-E2. Barley Diets and Control SE of Anaerobic A l k a l i Acid Dried Control** Mean D i g e s t i b i l i t y (%) Dry Matter 80.1 C* 84.9 b 80.1° 78.4° 89.3 3 0.6 Nitrogen (true) 89 .4 b 77 .4 d 86.9° 88.2 b c 98.3 a 0.6 Nitrogen U t i l i z a t i o n (%) B i o l o g i c a l Value 82.2 b 61.4 C 77.0 b 80.1 b 88.9 a 1.9 Net Protein 73.5 b 47.5 d 66.9° 70.7 b c 87.5 a 1.6 U t i l i z a t i o n *Means within rows with u l i k e superscript l e t t e r are s i g n i f i c a n t l y d i f f e r e n t (P < 0.001). **Balanced d i e t prepared according to Eggum (1973) ( / kg) 1:100 mixture of L-methionine and casein 105 g; vitamin mixture 8 g ; mineral mixture 40 g; nitrogen-free mixture 847 g. Refer to Table 8 for composition of mixtures. In f a c t , the whole a l k a l i - t r e a t e d barley tended to have a lower DM d i g e s t i b i l i t y in pigs than the whole acid-treated barley which contrasts with published r e s u l t s obtained with ruminants. There was also no di f f e r e n c e i n any of the d i g e s t i b i l i t y parameters between the whole and r o l l e d , chemically, preserved barley. This observation i s in general agreement with the r e s u l t s of Frape et a l . (1968 b), who recorded DM d i g e s t i b i l i t y for untreated r o l l e d and whole barley as being the same in - 92 -pigs of nine weeks of age. However, he also reported improved DM d i g e s t i b i l i t y of r o l l e d grain compared with whole grain in older pigs. Beames and Ngwira (1978) have found ground grain to be generally superior to whole grain rations for pigs. Feed u t i l i z a t i o n by pigs also appears to be governed by the degree of mastication and the rate of ingestion which both a f f e c t the p a r t i c l e s i z e of the g r a i n . These observations suggest that r o l l i n g alone i s not always s u f f i c i e n t to increase the d i g e s t i b i l i t y of pig rations above that of whole gra i n . Neutral detergent f i b r e d i g e s t i b i l i t y of dried barley was s i g n i f i c a n t l y (P < 0.001) reduced for pigs (Table 11). This r e s u l t was possibly due to the removal of some of the f i b r e f r a c t i o n s during drying, r e s u l t i n g in a lower NDF content in the grain (see Table 13). The f i b r e f r a c t i o n removed was most l i k e l y the more d i g e s t i b l e f i n e m a t e r i a l . Fecal NDF remained c o n s i s t e n t l y the same for a l l treatments. Table 13. Chemical composition of high-moisture barley from Peace River preserved in four d i f f e r e n t ways for Phase I. Method of Preservation Composition Anaerobic A l k a l i Acid Dried Dry matter (%) 83.3 78.2 82.8 86.7 NDF (g/100 g DM) 45.2 33.8 45.9 35.1 Nitrogen (g/100 g DM) 1.83 1.65 1.81 1.62 The NDF contents of the barley treatments (Table 13) appear to be high, as the crude f i b r e (CF) content of barley i s generally about 6-8%. However, these NDF values are comparable to those recorded by - 93 -Saunders and Hautala (1979), who found wheat bran to have NDF and CF contents of 49.7% and 12.2%, res p e c t i v e l y . Also, Schaller (1977) repor-ted NDF values as high as 89% for corn bran and 36% to 49% for wheat br-an. The NDF analysis attempts to measure the dietary f i b r e content of the feed that i s i n d i g e s t i b l e to the monogastric animal. Consequently, hemicellulose i s included in the NDF f r a c t i o n , which i s the major compo-nent that separates NDF from acid detergent f i b r e , more commonly analyzed for ruminant n u t r i t i o n . However, i t i s surmised from the high NDF d i g e s t i b i l i t y figures found in Table 11, that either some hemicellu-lose i s d i g e s t i b l e by monogastrics or some undetermined d i g e s t i b l e a r t i -fact was present i n the NDF f r a c t i o n , possibly starch. I t was noted by Schaller (1977), that when NDF analysis i s performed on cereal products of high starch content, some starch i s l e f t in the f i b r e residue. C o e f f i c i e n t s depicting nitrogen u t i l i z a t i o n for both pigs and rats fed a l k a l i - t r e a t e d barley were a l l adversley affected (P<0.001) (Tables 11 and 12). Decreases in the nitrogen d i g e s t i b l i t y , as a r e s u l t of a l k a l i treatment, were in the order of 10 percentage units in rats and 20 percentage units in pigs. Net protein u t i l i z a t i o n (NPU = true nitrogen d i g e s t i b i l i t y x b i o l o g i c a l value) in rats was approximately 20 percentage units lower for NaOH-treated barley. These r e s u l t s are s i m i l a r to those of De Groot and Slump (1969), who recorded 20% and 10% respective decreases in NPU of a l k a l i - t r e a t e d soybean o i l meal and casein when fed to rats. Depending on the consistency of the c o r r e l a -t i o n between true nitrogen d i g e s t i b i l i t y and NPU, i t may be safe to assume that the NPU in pigs could have been even lower than that i n rats when fed a l k a l i - t r e a t e d barley. This statement i s based on the present - 94 -f i n d i n g s , where true nitrogen d i g e s t i b i l i t y of a l k a l i - t r e a t e d barley was approximately 10 percentage units lower for pigs than for r a t s . Unfortunately, pig urine was not c o l l e c t e d in t h i s t r i a l and there are no reports in the l i t e r a t u r e on a l k a l i - t r e a t e d grain for pigs to substantiate t h i s statement. There are at least three factors which could have contributed to the poor nitrogen u t i l i z a t i o n of a l k a l i - t r e a t e d barley in the two species: v i z . , (1) racemization, whereby L amino acids change to D-forms which are mostly unavailable to the monograstric, (2) formation of lysinoalanine (LAL), a synthetic amino acid that reduces l y s i n e quantity and a v a i l a b i l i t y and (3) browning reaction, which reduces ly s i n e a v a i l a b i l i t y by binding with reducing sugars - the l a s t mentioned factor was most apparent, as the grain turned a dark reddish-brown colour within a few hours after NaOH treatment. These three factors were discussed at greater length in the l i t e r a t u r e review. In the rat t r i a l (Table 12) true nitrogen d i g e s t i b i l i t y and NPU were s i g n i f i c a n t l y (P < 0.001) higher for the anaerobic barley than for the acid and the a l k a l i - t r e a t e d barleys. There was no s i g n i f i c a n t d i f f e r e n c e between these values for the dried barley and the anaerobic and acid-treated barleys. However, in the pig t r i a l (Table 11) there was no difference in apparent or true nitrogen d i g e s t i b i l i t y between the non-alkali treatments, although there was a trend towards higher c o e f f i -c i e n t s for dried barley. These differences among the non-alkali t r e a t -ments, although not s i g n i f i c a n t , are s i m i l a r to those reported in the l i t e r a t u r e . Livingstone et a l . (1971) found DM d i g e s t b i l i t y and true nitrogen d i g e s t i b i l i t y by pigs of r o l l e d barley to be higher when dried - 95 -(82.7 and 84.1%, re s p e c t i v e l y ) than when moist (81.4 and 81.0%) or acid-treated (80.6 and 80.0%). These d i f f e r e n c e s were s i g n i f i c a n t but small. Forbes (1965) also reported s i m i l a r f i n d i n g s , but found nitrogen-retention to be highest in pigs fed high-moisture barley, which i s consistent with the higher NPU found in r a t s fed the anaerobic (high-moisture) barley i n the present t r i a l (Table 12). In the study by Livingstone et a l . (1971), the d i e t s tested were those used for f i n i s h -ing hogs; consequently, the d i e t s contained protein supplement to increase the crude protein content to 19.3%. This may have accounted for the higher true nitrogen d i g e s t i b i l i t y values obtained ( i n the order of 10 percentage units higher) as compared to those in the present pig t r i a l (Table 12), where the crude protein of the barley d i e t s averaged approximately 10.9%. The d i e t s in the present experiment were supplemented only with a vitamin and mineral mixture. Throughout both t r i a l s , health of the animals was good. However, inconsistent r e s u l t s were obtained from one pig fed whole, a l k a l i -treated barley due to a low and e r r a t i c feed intake. These r e s u l t s were not included in the s t a t i s t i c a l a n a l y s i s . Three r a t s , also fed the a l k a l i - t r e a t e d barley, did not consume t h e i r t o t a l d i e t (50 g DM) over f i v e days. The feed residues (4.0, 7.0 and 12.9 g/rat) were weighed and accounted for according to the method of Eggum (1973) . Feces from both the pigs and rats fed a l k a l i - t r e a t e d barley were dark brown in colour, s t i c k y and had a d i s t i n c t odour. These c h a r a c t e r i s t i c s of a l k a l i - t r e a t e d barley were also observed in ruminants fed s i m i l a r grain by Anderson et a l . (1981). They reasoned that the increased rate of passage of the treated grain a l t e r e d the mode of d i g e s t i b i l i t y - 96 -r e s u l t i n g i n low f e c a l pH and high f e c a l starch content, producing feces with d i f f e r e n t physical c h a r a c t e r i s t i c s . It i s possible that t h i s same explanation may hold true for monogastrics since the feces c h a r a c t e r i s -t i c s were s i m i l a r to those of ruminants. The grain treatments remained in both good v i s u a l and physical condition throughout the t r i a l with no sign of fungal growth or d e t e r i o r a t i o n . The treatments were not monitored m i c r o b i o l o g i c a l l y . However, la t e i n the pig t r i a l mites were noticed on the surface of the container holding the anaerobic barley. The grain from the top of the container, although not v i s i b l y a f f e c t e d , was removed and the t r i a l was completed as designed with seemingly uninfested barley. Braude et a l . (1980) recorded lower feeding values for pigs fed grain that was heavily i n f e s t e d with mites and incubated for nine weeks. The mites caused d e t e r i o r a t i o n of the feed and lowered i t s nutrient value s i g n i f i c a n t l y . In the present pig t r i a l , i t i s almost c e r t a i n that some mites were present i n the anaerobic barley fed to pigs, but the e f f e c t of the mites cannot be ascertained. However, the e f f e c t of the mites, i f any, was l i k e l y very small as the anaerobic barley showed no signs of physical d e s t r u c t i o n or loss of nutrient value. Nevertheless, the presence of the mites should be taken into consideration regardless of the degree of i n f e s t a t i o n , since these organisms would c e r t a i n l y not have enhanced the feeding value of the anaerobic barley for pigs. There was no evidence of mites i n the grain sample fed to r a t s , which was withdrawn from storage in early spring under cool conditions which are not conducive to the propagation of mites. - 97 -In t h i s study, the NaOH-treated barley gained 4.8 percentage units of water which was added during the application of the 32% NaOH sol u t i o n , as recommended by Orskov et a l . (1980). The solution made the grain appear very wet as the kernels clung together. This wet material was handled in large p a i l s a f t e r mixing as i t would not pass through a 10 cm diameter auger. The moisture was subsequently absorbed during storage. At time of removal, the NaOH barley had turned into a hard, s o l i d mass. The grain had to be loosened with a ste e l bar and then shovelled i n clumps up to 30 cm diameter. Similar problems with ammonia-treated grain have been reported by Pe p l i n s k i et a l . (1978). Problems with grain flow were not experienced i n any of the non-alkali treatments. 2. Phase-II 2.1 Experiment 1: D i g e s t i b i l i t y T r i a l with Sheep Fed Barley-Straw from Lacombe Chemical composition, voluntary intake and d i g e s t i b i l i t y data for sheep given high-moisture straw (HMS) and f i e l d - d r y straw (FDS) are presented in Table 14. Both HMS and FDS were fed as sole components of the d i e t . Because of the low p a l a t a b i l i t y and low n u t r i t i v e value, the DM intakes were below maintenance l e v e l . However, to evaluate the true n u t r i t i v e values of the straws, concentrate supplements were not included in the die t s in order to prevent the occurrence of possible associative e f f e c t s . Despite the low l e v e l s of intake, d i g e s t i b i l i t y c o e f f i c i e n t s should not have been greatly affected. T a i t (1979) reported no s i g n i f i c a n t differences in d i g e s t i b i l i t y when comparing low and high l e v e l s of barley-grain intake with sheep. - 98 -Table 14. Composition, voluntary intake,and apparent d i g e s t i b i l i t y of barley-straw from high-moisture and f i e l d - d r i e d barley from Lacombe, fed to sheep in PII-E1. Type of Straw High-Moisture F i e l d - D r i e d SE of Mean Composition (%) Dry matter Ash Acid detergent f i b r e Nitrogen 86.0 10.3 50.0 1.04 86.0 8.7 54.2 0.76 Voluntary Intake (g DM/day) 294 256 Apparent D i g e s t i b i l i t y (%) Dry matter a* 37.7 b 32.8 1 .0 Organic matter 39 .9 3 35.8 1 .2 Acid detergent f i b r e 33 .8 3 34.1 3 1 .6 Nitrogen 4 5 . I a 10.7 b 2.6 •Means within rows with d i f f e r e n t superscript l e t t e r s are s i g n i f i c a n t l y d i f f e r e n t (P < 0.001) In the present t r i a l , there was v i r t u a l l y no apparent d i f f e r e n c e i n the appearance or the dry matter content of the two straws. Nevertheless, a l l the d i g e s t i b i l i t y c o e f f i c i e n t s were s i g n i f i c a n t l y (P < 0.001) greater for the HMS, except for acid detergent f i b r e (ADF) where there was no d i f f e r e n c e . Dry matter d i g e s t i b i l i t i e s were s l i g h t l y lower than those reported by Mowat and Ololade (1970), who fed untreated barley straw supplemented with soybean meal to sheep. In t h e i r experiment the as s o c i a t i v e e f f e c t of protein supplement was not taken into account. In the present experiment, the nitrogen content of the HMS was 0.28 percentage units higher than that of FDS, which was associated with a s i g n i f i c a n t l y (P < 0.001) increased apparent nitrogen - 99 -d i g e s t i b i l i t y of approximately 35 percentage units above FDS. One of the suggested advantages of harvesting HM barley i s the increased n u t r i t i v e value of the straw (Mederick et a l . 1982). The data presented from t h i s t r i a l tends to support t h i s contention. It was determined i n t h i s t r i a l that HMS i s n u t r i t i o n a l l y superior to FDS, but the po t e n t i a l value of HMS as a nutrient source i n maintenance and growth di e t s should be evaluated further in feeding t r i a l s by incorporating the straw at varying l e v e l s of i n c l u s i o n . The ewes remained i n good health throughout the t r i a l even though they did loose up to 9 Kg body weight. However, the animals were somewhat over weight at the beginning of the t r i a l . 2.2 Experiment 2; D i g e s t i b i l i t y and Nitrogen-Retention T r i a l with Sheep Fed Whole Barley Grain from Lacombe The chemical compostion of the barley i s presented in Table 15. Dry matter content was for high-moisture (HM) barley was s u r p r i s i n g l y low. O r i g i n a l l y , the DM content of the HMB was assessed at 67%, but aft e r four months of storage t h i s value was reduced to 56% DM. Forbes (1965) recorded an increase of 2-3% in moisture content of barley stored hermetically. Although t h i s increase was due to fermentation, i t does not completely explain the present conditions -where the moisture content increased from approximately 33% to 44%. Reasons for DM losses i n grain stored anaerobically were discussed previously in the l i t e r a t u r e review, with losses reported as high as 5% in grain stored over 30% moisture (Forbes 1965; Meiering et a l . 1966). L i k e l y , the reason for the s u r p r i s i n g l y low DM content of the HMB was due to inaccurate DM assessment of the t o t a l grain bulk i n i t i a l l y , which was compounded by - 100 -Table 15. Chemical composition of barley harvested and preserved in various ways from Lacombe for Phase I I . Type of Barley Composition F i e l d Dry A r t i f i c i a l l y Dry High-Moisture Reconstituted Dry matter (%) 87.6 88.8 56.4 71.0 Ash (%DM) 4.1 3.8 4.0 3.0 Acid detergent f i b r e (%DM) 10.6 10.8 11.9 10.6 Nitrogen (%DM) 2.3 2.2 2.3 2.3 fermentation losses. Ash content of the reconstituted barley (RB) was approximately 1.0% lower than the compared treatments. This difference may be explained by the washing e f f e c t that r e c o n s t i t u t i o n may have had on the grain; consequently, less contamination (dust and mineral p a r t i c l e s ) from harvesting would have been present on the grain at time of analysis. The percent ADF was greatest for the HMB and lower for ADB, which was dried from HMB. These findings are in agreement with the l i t e r a t u r e ( K r a l l 1972; Marx 1978) and are also s i m i l a r to e a r l i e r findings in PI-EI. Nitrogen contents were v i r t u a l l y unchanged between treatments. Nitrogen-retention and d i g e s t i b i l i t y data for barley grain preserved in four d i f f e r e n t ways when fed to sheep are presented in Table 16. Neither period nor period x treatment e f f e c t s were s i g n i f i c a n t . However, the s i g n i f i c a n c e of differences between treatment means was not altered by pooling these e f f e c t s with the error variance. - 101 -Table 16. Nitrogen retention and d i g e s t i b i l i t y of whole barley-grain preserved i n four d i f f e r e n t ways from Lacombe determined with sheep i n t r i a l PII-E2. Type of Barley F i e l d A r t i f i - High- Reconsti- SE of Dry c i a l l y Dry Moisture tuted Mean D i g e s t i b i l i t y (%) 77.8 a b* 78.8 3 b Dry matter 76.8 b 79.4 a 0.6 Organic matter 7 9.9 a b 78.5 b 81.2 a 81.3 3 0.5 Acid detergent 31.3 b 21.9° 41.8 a 32.9 b 2.0 f i b r e a a a a Nitrogen 76.2 74.7 78.6 79.2 1.0 N itrogen-retention 28.3 a 26.0 a 27.3 a 24.7 a 3.7 <%) *Means within rows with no common superscript l e t t e r are s i g n i f i c a n t l y d i f f e r e n t (P < 0.01). Dry matter d i g e s t i b i l i t y for RB was s i g n i f i c a n t l y (P < 0.01) higher than that of a r t i f i c i a l l y dry barley (ADB), but the same as f i e l d dry barley (FDB) and HMB. Organic matter (OM) d i g e s t i b i l i t i e s for HMB and RB were both s i g n i f i c a n t l y (P < 0.01) higher than that of ADB, but the same as the d i g e s t i b i l i t y of FDB. Although not conclusive, these r e s u l t s tend to suggest that moist barley i s more d i g e s t i b l e than dry barley, e s p e c i a l l y when the barley i s dried a r t i f i c i a l l y . These findings are in general agreement with those of McGinty et a l . (1967) and Matsushima and Stenguist (1967), who reported reconstituted e n s i l e d HM sorghum and ens i l e d HM corn, r e s p e c t i v e l y , to be higher i n d i g e s t i b i l i t y than the corresponding dry grains f o r c a t t l e . McKnight et a l . (1973) also found e n s i l e d corn to be more d i g e s t i b l e i n terms of DM, 0M and energy than dry corn i n c a t t l e . However, Harpster et a l . (1975) found no d i f f e r e n c e - 102 -i n DM d i g e s t i b i l i t y between e n s i l e d HM and dry sorghum in sheep. K r a l l (1972) reported no advantage i n feeding reconstituted, ensiled barley to stee r s , but he did record an i n i t i a l advantage i n feeding HM barley to f i n i s h i n g s t e e r s . Therefore, there are c o n f l i c t i n g r e s u l t s in the l i t e r a t u r e , many of which may be a r e s u l t of d i f f e r e n c e in animal and grain species. Nevertheless, i t i s generally accepted that HM grains tend to have a slower rate of passage from the rumen, which increases ruminal carbohydrate digestion and decreases the amount of soluble carbohydrate that reaches the abomasum (McKnight et a l . 1973; McNeill et a l . 1971). Generally then, HM or reconstituted grain, as compared to dry grain, should provide an equivalent i f not improved d i g e s t i b i l i t y , when fed to ruminants. Acid detergent f i b r e (ADF) d i g e s t i b i l i t y for ADB was s i g n i f i c a n t l y (P < 0.01) lower than that of a l l other treatments, with HMB highest and FDB and RB being intermediate. It appears that the drying process reduces the ADF content of the grain (Table 13 and 15) but that t h i s material i s of a lower d i g e s t i b i l i t y . This reasoning i s supported by the fact that r e c o n s t i t u t i n g had no e f f e c t on ADF d i g e s t i -b i l i t y (RB was reconstituted from FDB). This suggests that the hemicellulose and c e l l u l o s e - l i g n i n bonds in the grain f i b r e were not aff e c t e d by the addition of water or by the e f f e c t s of a i r t i g h t storage. Consequently, ADF d i g e s t i b i l i t y does not appear to be dependent on moisture content per se, but rather on the physical quantity and composition of the f i b r e present in the g r a i n . These f a c t o r s are more c l o s e l y r e l a t e d to the harvesting conditions associated with HM grain ( i . e . thins and fi n e s are heavier due to high moisture - 103 -content and are not blown out during combining, r e s u l t i n g i n higher g r a i n - f i b r e contents). The data presented e a r l i e r i n Table 9 showed that HMB had an increase i n f i n e s , chaff and straw above that of ADB by 1.5 percentage u n i t s . K r a l l (1972) suggested that t h i s increase in f i b r e content was one reason why steers adapted to HM barley "faster than dry barley and without d i g e s t i v e upsets. Also, heat from the drying process may have a negative e f f e c t on ADF d i g e s t i b i l i t y since ADF d i g e s t i b i l i t y of the ADB was even lower (P < 0.01) than that of the FDB. There was no d i f f e r e n c e in e i t h e r nitrogen-retention or nitrogen d i g e s t i b i l i t y between treatments. These findings are in general agreement with those of McKnight et a l . (1973) who recorded s i m i l a r nitrogen-retentions of HM and dry corn by c a t t l e . C o n f l i c t i n g r e s u l t s were recorded by Harpster et a l . (1975) who found a s i g n i f i c a n t l y higher nitrogen d i g e s t i b i l i t y for dry sorghum compared to HM grain and a s i g n i f i c a n t l y lower nitrogen-retention for dry grain compared to HM grain with sheep. In spite of these findings, ensiled grain has been shown by 3ones et a l . (1970) and McKnight et a l . (1973) to have higher soluble crude protein l e v e l s than dry g r a i n . This increase in soluble protein provides the rumen microorganisms with more r e a d i l y d i g e s t i b l e p r o t e i n , but at the same time reduces protein for rumen by-pass which could be more e f f i c i e n t l y digested and u t i l i z e d i n the small i n t e s t i n e . It may be important to note here that the actual nitrogen content of f r e s h l y harvested HM grain should not vary from corresponding f i e l d dry grain as some l i t e r a t u r e suggests i t does (Marx 1978). The reason for t h i s i s that once the grain becomes p h y s i o l o g i c a l l y mature (approximately 40% moisture for barley) the only further change i n - 104 -chemical composition of the grain i s , t h e o r e t i c a l l y , a reduction in moisture content. Therefore, based on the d e f i n i t i o n of p h y s i o l o g i c a l maturity, the nitrogen content of the grain should be the same for both HM and dry g r a i n . However, the nitrogen content of HM grain may increase s l i g h t l y during hermetic storage. This increase i s caused by a concentration e f f e c t induced by the loss of carbohydrates caused by CO2 production during fermentation. Consequently, the remaining dry matter has a higher concentration of nitgrogen, but, as a r e s u l t , w i l l be lower i n soluble carbohydrates (Hyde 1974). This phenomenon may lead to misleading conclusions about the nitrogen content of HM g r a i n . Also, grain dried a r t i f i c i a l l y at high temperatures (> 88°C) may have poorer protein q u a l i t y , but the nitrogen content of the grain w i l l remain the same (Brooker et a l . 1974). The animals remained in good health throughout the t r i a l and feed residues were not incurred. Feces from the ewes were soft and poorly formed during the adaption period for a l l four treatments. However, as the t r i a l progressed the feces f o r a l l treatments were well formed, but generally smaller p e l l e t s were formed as compared to sheep fed a balanced r a t i o n . There was no sign of scours in sheep fed HMB as reported by Harpster et a l . (1975). The HMB was considerably darker in colour than the dry grains and i t had a t y p i c a l s i l a g e smell. Hyde and Burrel (1973) found s i m i l a r c h a r a c t e r i s t i c s in grain stored over 25% moisture. The RB did not d i s c o l o u r and even though i t was over 25% moisture, a s i l a g e - l i k e smell did not develop. It was noted e a r l i e r i n the l i t e r a t u r e review, that c h a r a c t e r i s t i c s t y p i c a l of e n s i l e d products are dependent on temperature. - 105 -In t h i s case i t was f e l t that the ambient temperatures were too low to allow proper fermentation to proceed i n the small 23 1 p a i l s which held the grain; however, some r e s p i r a t i o n must have occurred as pressure was released from the p a i l s upon opening. The t r i a l was conducted during the winter of 1982; consequently, the ambient temperatures were below those optimum for good fermentation to develop. 2.3 Experiment 3: Nitrogen Balance T r i a l with Rats Fed Barley from Lacombe Due to the small a v a i l a b l e q u a n t i t i t e s of the barley treatements, rats were chosen as models for pigs in t h i s t r i a l . Eggum and Beames (1981) have suggested that there i s good agreement between rats and pigs regarding responses to v a r i a t i o n s in protein composition and a v a i l a b i -l i t y and nutrient d i g e s t i b i l i t y . Consequently, samples of HMB from the top 1/3 and bottom 1/3 of the storage drums were c o l l e c t e d and evaluated separately with r a t s . The purpose of t h i s segment of the experiment was to t r y to determine i f the n u t r i t i o n a l value of the grain varied from top to bottom in the drum. The drums were intended to simulate large a i r t i g h t s i l o s where moisture and organic acid migration occurs (Hyde 1974). The migration of these products may a f f e c t the n u t r i t i o n a l q u a l i t y of the barley. However, i t i s acknowledged that in these drums the d i f f e r e n c e s detected, i f any, would l i k e l y be small. The s i z e of the 203 1. storage drums could not i d e n t i c a l l y simulate those conditions present in large s i l o s with respect to the development of temperature gradients which af f e c t moisture migration and possibly nutrient q u a l i t y . As mentioned e a r l i e r , Lancaster et a l . (1974) noted the extreme d i f f i c u l t i e s incurred when attempting to duplicate e f f e c t s of - 106 -large scale storage of HM grain under smaller or laboratory conditions. In the present t r i a l , temperature of HMB in the drums was not monitored, for the above reasons, and v a r i a t i o n s i n moisture and nitrogen content were n e g l i g i b l e within both drums. Dry matter (DM) d i g e s t i b i l i t y and nitrogen u t i l i z a t i o n by ra t s of barley harvested and preserved in d i f f e r e n t ways are presented i n Table 17. There was no d i f f e r e n c e i n DM d i g e s t i b i l i t y for a l l four Table 17. Dry matter d i g e s t i b i l i t y and protein u t i l i z a t i o n c o e f f i c i e n t s of barley harvested and preserved i n various ways determined with rats in PII-E3. Barley Diets and Control F i e l d A r t i f i -c i a l l y Bottom HM# Top Control^ SE of Mean Dry Dry HMf D i g e s t i b i l i t y (%) Dry matter Nitrogen (true) b* 79.7 89.0° 80.0 b 89.1 C 79.6 b 91 .2 b 79.2 b 90.8 b 89.1 3 99.2 3 0.5 0.4 Nitrogen U t i l i z a t i o n (%) B i o l o g i c a l value 82.3 b 82.2 b " 75 .4 C 77.6° 100.5 a 1.1 Net protein u t i l i z a t i o n 73.3 b 73.4 b 68.8° 70.5 b c 99.7 a 1.1 •Means within rows with unlike superscript l e t t e r are s i g n f i c a n t l y d i f f e r e n t (P < 0.001). HMB sampled from the bottom t h i r d of 203 1 storage drum. HMB sampled from the top t h i r d of 203 1 storage drum. Balanced d i e t c o n s i s t i n g of casein, L-methionine, nitrogen-free mixture and vitamin and mineral mixtures, according to Eggum (1973) (Same as in Table 12). - 107 -barley d i e t s . True nitrogen d i g e s t i b i l i t i e s of both HMB treatments were s i g n i f i c a n t l y (P < 0.001) improved above both f i e l d dry barley (FDB) and a r t i f i c i a l l y dry barley (ADB). It would appear from these r e s u l t s that the fermentation of the HMB increased the a v a i l a b i l i t y of the crude protein as suggested by Holmes et a l . (1973) and McKnight et a l . (1973) . However, the protein q u a l i t y of the HMB must have been poorer than that of the dry grains as the b i o l o g i c a l values for the HMB treatments were s i g n i f i c a n t l y (P < 0.001) lower than the dry barley treatments. In other words, protein from HMB was more d i g e s t i b l e , but was of a lower b i o l o g i c a l value than ei t h e r of the dry treatments (FDB and ADB). O v e r a l l nitrogen u t i l i z a t i o n , as measured by net protein u t i l i z a t i o n , was the same for FDB, ADB and HMB (top), but HMB (bottom) was s i g n i f i c a n t l y (< 0.001) lower than FDB and ADB. Based on t h i s data alone, barley e i t h e r f i e l d dried or a r t i f i c i a l l y dried from HMB could be recommended above HMB as a feed for rats and, consequently, for pigs. However, these findings c o n f l i c t with those of Forbes (1965), who reported opposite r e s u l t s to those in the present t r i a l . He fed dry and HM barley to pigs and observed a higher nitrogen d i g e s t i b i l i t y for the dry barley but a higher nitrogen retention for the HMB. Livingstone et a l . (1971), as reported e a r l i e r , also recorded a higher nitrogen d i g e s t i b i l i t y by pigs of dry barley than of HMB. However, Oones et a l . (1974) l i s t e d several references noting that HM grain i s generally as good as or better than dry grain for swine. From the r e s u l t s i n the present t r i a l and those from the l i t e r a t u r e , the question may be asked i f the benefits of HM grain are - 108 -not due, at l e a s t p a r t i a l l y , to the moisture content of the g r a i n . Due to the design of t h i s rat t r i a l , i t was necessary to dry the HMB (by freeze drying) in order for i t to be both f i n e l y ground and s a f e l y stored during the t r i a l . However, by drying the HMB p r i o r to consumption by r a t s , the advantages in terms of DM d i g e s t i b i l i t y and nitrogen-retention, as mentioned for pigs in the l i t e r a t u r e , may have been f o r f e i t e d . Holmes et a l . (1973) surmised that improved feeding values obtained in pigs fed HM corn were due to a prolonged retention time of the HM grain i n the stomach as compared to the dry g r a i n . This increased retention time was presumably due to the c h a r a c t e r i s t i c s of e n s i l e d grain (pH, moisture content, soluble f r a c t i o n s , etc.) which on a whole were c e r t a i n l y altered in the HMB by drying before being tested i n the r a t s ; consequently, a longer retention time may not have occurred f o r HMB treatments. Po s s i b l y for t h i s reason, the r e s u l t s i n the rat t r i a l were not consistent with those reported for pigs by Forbes (1965) and Holmes et a l . (1973). Also on a speculative basis, l y s i n e a v a i l a b i l i t y may have been reduced due to the factors associated with browning which occurred during anaerobic storage of the HMB. Again, l y s i n e i s the f i r s t l i m i t i n g amino acid for growth in pigs and rats r e c e i v i n g barley as the sole dietary component (Aw Yong and Beames 1975) . Also, rats have a higher requirement for s u l f u r containing amino acids (methionine and cystine) than pigs (Eggum and Beames 1981). I f methionine were l i m i t i n g , t h i s may also be a possible explanation for c o n f l i c t i n g r e s u l t s in the present t r i a l , since even though cystine can replace about one-sixth of the methionine requirement, cystine does not have a growth e f f e c t in the absence of methionine in the young rat (Maynard and L o o s l i 1969). - 109 -As stated e a r l i e r , the explanations given for the c o n f l i c t i n g r e s u l t s of t h i s t r i a l are based mainly on theory and speculation. The r e s u l t s obtained were l i k e l y caused by one or more of the possible explanations given. Comparative data on barley preserved i n s i m i l a r ways to those i n t h i s t r i a l when fed to rats or pigs are very l i m i t e d . 3 . Phase I I I 3.1 Experiment 1: D i g e s t i b i l i t y and Nitrogen-Retention T r i a l with Sheep Fed Reconstitued, A l k a l i - T r e a t e d Barley Table 18. Nitrogen-retention and d i g e s t i b i l i t y data for reconstituted a l k a l i - t r e a t e d , whole barley determined with sheep in t r i a l PIII-E1. Whole Barley Treatments Reconsti- RB+NaOH RB+1% NH3 RB+3% NH3 SE of Mean tuted (RB) D i g e s t i b i l i t y (%) Dry matter bA 79.9 o~ „ab 82.0 83.4 a b „„ ab 81 .9 84.2 a b 83 .6 a * 0.7 Organic matter 82.0 85 .9 3 0.7* Acid detergent f i b r e 26.5 3 21.7 a 6.7 b i . o b 4.4** Nitrogen 79.9 3 62.1 b 78.6 a 83.3 a 1.4** Nitrogen retention 26.5 a 26.3 a 25.2 a 26.2 a 2.4 (%) 'Means within rows with unlike superscript l e t t e r are s i g n i f i c a n t l y d i f f e r e n t * (P < 0.01) ** (P < 0.001) Ammoniated treatments were corrected for DM content as described in the materials and methods. The co r r e c t i o n s values were determined by analyzing for nitrogen content before and af t e r oven drying. The d i f f e r e n c e in nitrogen content between the two measurements was added to the dry matter content. The c o r r e c t i o n values were 0.504% and 2.216% DM for 1 and 3% NH3, r e s p e c t i v e l y . - 110 -Nitrogen-retention and d i g e s t i b i l i t y data for reconstituted, whole barley stored anaerobically and preserved with NaOH, 1% NH3 or 3% N H 3 , determined with sheep are presented i n Table 18. Dry matter (DM) d i g e s t i b i l i t y of reconstituted barley (RB) was s i g n i f i c a n t l y (P < 0.01) lower than that of the 3% NH3-RB. S i m i l a r r e s u l t s were reported by Laksesvela (1981) when he compared N H 3-treated and untreated whole barley i n sheep and observed an increase i n DM d i g e s t i b i l i t y for NH3 -treated (3% a i r dry basis) grain of f i v e percentage u n i t s . However, a s i g n i f i c a n t d i f f e r e n c e was not found between RB and NaOH-RB in the present t r i a l . This r e s u l t c o n t r a d i c t s those of Orskov and Greenhalgh (1977) and Orskov et a l . (1978, 1979, 1980), who have reported DM d i g e s t i b i l i t y of NaOH-treated (30 g NaOH/Kg a i r dry g r a i n ) , whole barley to be higher than that of untreated, whole barley and the same as r o l l e d barley, when fed as the sole component of the di e t to both c a t t l e and sheep. More recently though, as c i t e d e a r l i e r , Barnes and Orskov (1981) and Orskov et a l . (1981 b) have reported lower DM d i g e s t i b i l i t y of NaOH-treated, whole barley than that of untreated, r o l l e d barley when the grain was provided as a supplement to hay or s i l a g e for ste e r s . Consequently, they increased treatment l e v e l s from 30 to 40 g NaOH/Kg a i r dry barley in an attempt to increase the rate of digestion in the rumen. Orskov et a l . (1978) found that NaOH-treated barley gave a slower release of starch than mechanical grinding. This f i n d i n g , along with the fact that a l k a l i - t r e a t e d grains increase rate of passage (Orskov et a l . 1981a), was suggested to be advantageous in ruminants since less - 111 -int e r f e r e n c e would occur with the digestion of c e l l u l o s e when a l k a l i grain supplements roughage d i e t s . However, due to the increased rate of passage which occurs i n ruminants re c e i v i n g d i e t s containing long p a r t i c l e s (Thomson and Lemming 1972), the o r i g i n a l l e v e l of NaOH (30 g/Kg) as suggested by Orskov et a l . (1980), for optimum DM d i g e s t i b i l i t y of barley, has proved i n s u f f i c i e n t when the grain i s used as a supplement to roughage based d i e t s . Also as stated e a r l i e r , Anderson et a l . (1981) found f e c a l pH to be lowest in steers fed a l k a l i - t r e a t e d grain, which contributes to abnormally high f e c a l starch contents (Wheeler and N a i l e r 1977). These observations suggest that the optimal l e v e l of NaOH a p p l i c a t i o n i s dependent on the way in which the grain i s to be eventually fed ( i . e . alone or with roughage). I f i t i s to be fed as the sole component of the d i e t , the l e v e l of a p p l i c a t i o n can be lower than i f the treated grain i s to supplement roughages. With roughages, a higher l e v e l of NaOH i s required to maintain optimum DM d i g e s t i b i l i t y of whole grain since the rate of passage w i l l be increased. These factors imply that the l e v e l of NaOH a p p l i c a t i o n f o r optimum DM d i g e s t i b i l i t y of whole grain by ruminants i s c r i t i c a l . Consequently, in the present t r i a l , DM d i g e s t i b i l i t y of NaOH-RB may have been s i g n i f i c a n t l y increased above RB i f the a p p l i c a t i o n rate had been higher, allowing for a fas t e r rate of dige s t i o n in the rumen. Also, the optimal l e v e l of a p p l i c a t i o n may be p a r t i a l l y d i c t a t e d by the f i b r e content of the gr a i n . For example, recommended rates of NaOH a p p l i c a t i o n vary between species of grain for optimum DM d i g e s t i b i l i t y - 112 -with oats (high f i b r e grain) r e q u i r i n g 45 g NaOH/Kg and wheat (low f i b r e grain) r e q u i r i n g approximately 20 g NaOH/Kg. Although, the barley i n the present t r i a l was not abnormally high in f i b r e content (Table 19), i t i s apparent from the l i t e r a t u r e that small d i f f e r e n c e s in f i b r e content could influence the e f f e c t of NaOH on DM d i g e s t i b i l i t y . Therefore, as the chemical compostion and n u t r i t i o n a l values of barley changes due to v a r i e t a l d i f f e r e n c e s and to growing conditions, i t i s also conceivable that the a p p l i c a t i o n rate of NaOH may have to vary i n order to optimize DM d i g e s t i b i l i t y . Table 19. Chemical composition of rec o n s t i t u t e d , a l k a l i - t r e a t e d barley for Phase I I I . Method of Preservation Reconstitu-ted (RB) RB+NaOH RB+1% NH3 RB+3% NH 3 Composition (DM%) Dry matter* 70.5 65.1 69.8 70.4 Ash 2.59 7.66 2.37 2.21 Acid detergent f i b r e 8.10 6.64 5.67 5.24 Nitrogen** 2.14 1.95 2.60 3.25 *Ammbniated treatments have been corrected for DM content as mentioned previously i n Table 18. ** Nitrogen contents of NH 3-treated barley were determined by placing 5 g ( a i r dry) treated barley d i r e c t l y into K jeldahl f l a s k s containing s u l f u r i c acid at both morning and afternoon feedings. Determinations were made on 6 d i f f e r e n t days and the average value for each NH3 treatment i s displayed. Organic matter d i g e s t i b i l i t y values were s i m i l a r to those for DM d i g e s t i b i l i t y with the only s i g n i f i c a n t (P<0.01) d i f f e r e n c e favouring 3% NH3-RB over RB. - 113 -There was no s i g n i f i c a n t d i f f e r e n c e for d i g e s t i b i l i t y of acid detergent f i b r e (ADF) between RB and NaOH-RB (Table 18). This r e s u l t i s i n agreement with those of Orskov and Macdearmid (1978) and Orskov et a l . (1980). However, ADF d i g e s t i b i l i t y was s i g n i f i c a n t l y (P < 0.001) lower for both N H 3-treated barley, between which there was no d i f f e r e n c e . These lower d i g e s t i b i l i t y values were not s u r p r i s i n g , as the percent ADF of the barley was just over 5% (Table 19) which were s i m i l a r to those recorded by Laksesvela (1981) for N H 3-treated barley. When the f i b r e content in the d i e t becomes very low, as in the NH 3-treated barley, the f i b r e d i g e s t i b i l i t y tends to decrease since the remaining f i b r e i n the grain i s made up mostly of i n d i g e s t i b l e l i g n i f i e d m a t e r i a l . Consequently, the d i g e s t i b i l i t y of the remaining ADF in the N H 3~treated barley was very low. Comparisons of ADF d i g e s t i b i l i t y from the present t r i a l cannot be made with those in the l i t e r a t u r e (Laksesvela and Slagsvold 1980; Laksesvela 1981; Mowat et a l . 1981), where N H 3~treated grain was fed in conjunction with basal d i e t s , leaving possible a s s o c i a t i v e e f f e c t s undetermined. Nitrogen d i g e s t i b i l i t y for NaOH-RB was s i g n i f i c a n t l y (P < 0.001) lower than the values obtained for the other three treatments, which were a l l the same. Further, percent nitrogen-retention of the four barley treatments in the t r i a l was unchanged (P < 0.05) . Since the nitrogren d i g e s t i b i l i t y of NaOH-RB was low, i t was not expected that the nitrogen-retention would be the same as in the other treatements. A possible explanation of t h i s phenomenon can be derived from the fi n d i n g s reported by Anderson et a l . (1981). As c i t e d e a r l i e r , the f e c a l pH of animals fed NaOH-treated grain i s often low as a r e s u l t of a high starch - 114 -content. While t h i s f e c a l material i s in the hind gut, a second fermentation process takes place in an attempt to u t i l i z e the remaining st a r c h . As a r e s u l t , the organisms responsible for the fermentation require a nitrogen source which i s supplied by urea r e c y c l i n g . Due to the increased rate of passage of NaOH-treated barley (Orskov et a l . 1981 a), the retention time of the ingested material in the hind gut w i l l be further reduced as compared with retention times i n animals fed untreated grain; thus, f e c a l nitrogen w i l l be increased. Therefore, i t appears that the actual nitrogen d i g e s t i b i l i t y of NaOH-RB may have been quite high anterior to the hind gut, but the supposedly high hind gut starch content possibly drew nitrogen back into the gut lumen, thereby reducing the apparent n i t r o g e n - d i g e s t i b i l i t y . P o s s i b l y , i f the a p p l i c a t i o n rate of NaOH had been greater, the starch in the diet may have been more f u l l y digested r e s u l t i n g i n less starch entering the hind gut and a reduction i n the reentry of urea-nitrogen. Values regarding nitrogen u t i l i z a t i o n of NaOH-treated grain for ruminants have not been reported. The nitrogen d i g e s t i b i l i t y values for N H 3-treated barley were s i m i l a r to those obtained by Laksesvela and Slagsvold (1980) and Laksesvela (1981). Neither the nitrogen d i g e s t i b i l i t y nor the nitrogen-retention values for the N H 3-treated barley were s i g n i f i c a n t l y d i f f e r e n t from the untreated, reconstituted barley. However, nitrogen retained (grams/day) from the barley treatments increased as the t o t a l nitrogen content of the grain increased with N H 3-treatment (Table 20). These r e s u l t s i n d i c a t e that the nitrogen retained i s c o n s i s t e n t l y proportional to the l e v e l of NH3 a p p l i c a t i o n . For example, the - 115 -proportions of nitrogen retained that were contributed by both NH3 treatments were the same as the proportion of nitrogen retained from Table 20. Actual d a i l y mean nitrogen contents of feed, feces and urine for sheep fed reco n s t i t u t e d , a l k a l i - t r e a t e d barley i n t r i a l PIII-E1. Barley Treatments Reconstitu-ted (RB) RB+NaOH RB+1% NH3 RB+3% NH3 Nitrogen Content (g/day) F e e d a b c 13.2 12.1 16.8 21.6 Feces 2.7 4.6 3.6 3.6 Urine 7.0 4.3 9.0 12.3 Feces and Urine 9.7 9.0 12.6 15.9 Nitrogen-Retained [feed-(feces + urine)] 3.5 3.2 4.2 5.7 Feed intake averaged 650 g DM/ewe/day among treatments. 'Nitrogen contents of the NH 3-treated barleys were determined as described on Table 19. 'Diets were normally consumed in under 5 minutes, therefore v a r i a t i o n i n nitrogen content of NH 3-barley was nonexistent from the time the barley was given to the ewe to the time i t was consumed. the grain i t s e l f . This i s also evident by the i n s i g n i f i c a n t d i f f e r e n c e in nitrogen d i g e s t i b i l i t y and nitrogen-retention found on Table 18, regarding NH3-RB. I t would be i n t e r e s t i n g to determine i f t h i s trend would continue with higher l e v e l s of a p p l i c a t i o n . Further studies should be conducted to c o r r e l a t e NH3 a p p l i c a t i o n l e v e l s and nitrogen-retention by ruminants, because to date only Mowat et a l . (1980) have attempted to do so on only a l i m i t e d b a s i s . However, the l o g i s t i c s of such a study may prevent i t from being conducted as intake - 116 -appears to be adversely affected by l e v e l of NH3 a p p l i c a t i o n , i f the grain i s not s u f f i c i e n t l y aerated with the concomitant loss of ammonia. Also, the i n i t i a l o b j e c t i v e of NH3 addition would be changed, with the emphasis placed on feeding value rather than on preservation. The ewes remained healthy throughout the t r i a l with s l i g h t gains in body weight being recorded. Feces from sheep fed NaOH-RB were s t i c k y and dark brown in colour and had a d i s t i n c t odour l i k e pig manure. The urine volume from these same ewes (fed NaOH-RB), increased by 350% over that of ewes fed RB. Water consumption was correspondingly greater but was not measured. Some sheep on both NH3 treatments developed diarrhea during the adaption period, but they had generally returned to normal by the s t a r t of the c o l l e c t i o n period. Feces from ewes fed NH3-RB varied -some were soft while the remainder was normal. Sodium hydroxide-RB was the same in appearance as the NaOH-barley from the Peace River batch, described in phase I, and the RB was the same in appearance as the reconstituted-barley from the Lacombe batch, described in phase II - experiment 2 in the r e s u l t s and d i s c u s s i o n . The 3% NH3-RB was only s l i g h t l y darker in colour than the 1% NH3-RB. Both P e p l i n s k i et a l . (1978) and Srivastava and Mowat et a l . (1980), noted evidence of the browning reaction in corn treated with NH 3. McGhee et a l . (1979) found that browning increased with higher l e v e l s of NH 3 and increased temperatures i n corn. In the present t r i a l , the degree of browning that took place i n the NH3~treated barley was by no means as severe as the browning observed in NaOH-treated barley. - 117 -3.2 Experiment 2; Nitrogen Balance T r i a l with Rats Fed Al k a l i - T r e a t e d Barley Dry matter (DM) d i g e s t i b i l i t y and protein u t i l i z a t i o n c o e f f i -c i e n t s for a l k a l i - t r e a t e d barley determined with rats are presented i n Table 21. As i n previous experiments (PI-E1 and E2), the NaOH-treated Table 21. Dry matter d i g e s t i b i l i t y and protein u t i l i z a t i o n c o e f f i c i e n t s of a l k a l i - t r e a t e d barley determined with rats in PIII-E2. Barley Diets Reconsti- RB+NaOH RB+1% RB+3% Un- SE of tuted (RB) NH3 NH3 treated Mean D i g e s t i b i l i t y (%) r * 82.0 Dry matter 86 .8 a 83 .9 b 84.6 b 82.5 C 0.3 Nitrogen (True) 88 .4 a 71 .6 b 90.1 a (89.9 af 90.9 a (90 .4 a) 90.3 a 0.7 Nitrogen U t i l i z a t i o n (%) B i o l o g i c a l Value 71 .2 b 54.4 d 65.8° 66.4° 75 .7 d 0.9 6 3 . 0 b ( b c ) (67.6°) (71 .0 b) Net protein 39.0 59.3° c 60.4 a 68.4 0.8 u t i l i z a t i o n (60.7 C) (64.1 b) *Means within rows with unlike superscript l e t t e r s are s i g n i f i c a n t l y d i f f e r e n t (P < 0.001). #Numbers and superscripts within brackets represents data corrected for r e s i d u a l NH3-N as described in PIII-E2 (Materials and Methods). barley produced s i m i l a r r e s u l t s regarding both DM d i g e s t i b i l i t y and the protein u t i l i z a t i o n c o e f f i c i e n t s . A l l protein u t i l i z a t i o n c o e f f i c i e n t s were s i g n i f i c a n t l y (P < 0.001) lower for the NaOH-RB than those for a l l - 118 -other treatments. The reasons for poor protein u t i l i z a t i o n by monogastric animals were discussed e a r l i e r . In t h i s experiment, as stated i n the methods, the NH3-treated grains were aerated u n t i l most of the NH3 had v o l a t i l i z e d . However, some NH3 remained i n the grain - approximatley 0.02% N for 1% NH3-RB and 0.05% N for 3% NH3-RB. The re s i d u a l NH3-N that remained i n the barley was deleted from the c a l c u l a t i o n s , as described e a r l i e r i n the materials and methods. The r e s u l t s of these c a l c u l a t i o n s are presented within brackets i n Table 21. The fig u r e s without brackets represent the barley as fed to the rats without numeric a l t e r a t i o n . These comparisons were made to determine i f the NH3 had any negative a f f e c t , s i m i l a r to that of NaOH, on the protein q u a l i t y of barley determined by the monogastric animal. By removing a l l the NH3-N, the r e s i d u a l e f f e c t of NH3 on protein q u a l i t y should be able to be ascertained. The true nitrogen d i g e s t i b i l t y of the unaltered and alte r e d (bracketed figures) barley are a l l the same as values for RB and untreated barley. However, the b i o l o g i c a l values d i f f e r somewhat, suggesting that the NH3-N was not as well metabolized as the nitrogen i n the non - a l k a l i treatments. The net protein u t i l i z a t i o n for the al t e r e d NH3 data changed for both 1 and 3% NH3-RB which indicates that NH3 had no s i g n i f i c a n t r e s i d u a l e f f e c t on protein q u a l i t y ( i . e . browning reaction, racemization, formation of lysinoalanine) when compared to RB. These findings indicated that the se v e r i t y of the a l k a l i n e condi-t i o n s produced by NH3 treatments were not as great as that produced by NaOH, which decrease protein q u a l i t y . There was also a s i g n i f i c a n t (P < 0.001) d i f f e r e n c e between the altered 1 and 3% NH3-RB data which i s - 119 -d i f f i c u l t to explain. Possibly the c o r r e c t i o n f a c t o r s (0.02 and 0.05%N) used for 1 and 3%-RB should have been proportioned between both f e c a l and urinary nitrogen rather than subtracted s o l e l y from urinary nitrogen. Nevertheless, the findings from the unaltered NH3 data suggested that NH3 was poorly u t i l i z e d by the monogastric as was evident from the b i o l o g i c a l value and net protein u t i l i z a t i o n f i g u r e s , but from the a l t e r e d NH3 data, there appeared to be l i t t l e i f any damage to the qu a l i t y of the barley p r o t e i n . Consequently, i f t h i s was the case, NH 3-treated grain could be fed to pigs without any negative e f f e c t on the u t i l i z a t i o n of protein supplied from the grai n , but with no n u t r i t i o n a l benefits from the added nitrogen of the N H 3 , i n contrast to the value of the NH3 for ruminants. There was a s i g n i f i c a n t (P < 0.001) increase i n DM d i g e s t i b i l i t y for 1 and 3% NH3-RB above both RB and untreated barley. This i n d i c a t e s , as with ruminants, that the a l k a l i treatments do chemically process the grain as mentioned by Laksesvela (1981), Mowat et a l . (1980) and several papers by Orskov et a l . (1977 to 1981). The n u t r i t i o n a l findings from NH 3-treated grain i n t h i s experiment were not compared with published r e s u l t s , as papers on t h i s subject regarding monogastric n u t r i t i o n , have apparently not been written. Throughout t h i s t r i a l , the rats remained i n good health, but feed residue was c o l l e c t e d from rats given NaOH-RB as in P1-E2. The feed residue varied between a l l f i v e rats on the treatment from 3.6 to 21.8 g DM of the t o t a l 50 g D M d i e t , and was accounted for according to Eggum (1973). A l l feces were s o l i d and well formed. Feces from rats on NaOH-RB had the same c h a r a c t e r i s i t i c s as described e a r l i e r i n PI - E2. - 120 -3.3 Experiment 3: NH3-Retention of Reconstituted, Ammoniated Barley The purpose of t h i s experiment was to determine the retention of NH3 i n reconstituted grain at varying moisture l e v e l s . It was apparent from the l i t e r a t u r e ( P e p l i n s k i et a l . 1978; Montgomery et a l . 1980; Srivastava and Mowat 1980; Van Cauwenberge et a l . 1981) that the reten-t i o n of NH3 varied greatly depending on the a p p l i c a t i o n method, type of storage v e s s e l , atmospheric temperature and grain moisture content. A l l these v a r i a b l e s remained constant i n t h i s experiment except for grain moisture content. The barley was reconstituted to varying moisture contents (12, 18, 24, 30 and 36%) and was treated in sealed glass j a r s with anhydrous-NH3 (3% w/w a i r dry basis) and stored for one week at room temperature. The nitrogen content of the barley (Table 22), upon removal from the sealed j a r s showed l i t t l e d i f f e r e n c e between treatments i n d i c a t i n g no loss of NH3 during sealed storage. Any s l i g h t v a r i a t i o n in nitrogen content of the treatments may have resulted during NH3 a p p l i c a t i o n as the method of i n j e c t i o n was f a i r l y crude. During aerated storage, the nitrogen content for a l l treatments decreased most r a p i d l y in the f i r s t two days (Figure 3) and the declined more slowly throughout the remainder of the test period. This decline in N H 3 -retention appeared to be c l o s e l y r e l a t e d to the loss i n moisture content of the grain (Figure 4), i n d i c a t i n g that the NH3 was bound to and, consequently, l o s t with the grain moisture. Supporting evidence for t h i s f i n d i n g was presented by both P e p l i n s k i et a l . (1978) and Mowat et a l . (1981), who reported the concentration of NH3 to be greatest in the dampest regions of the grain bulk. These regions were generally caused by moisture migration, - 121 -Table 22. Time of NH3 application and NHVretention (nitrogen %) of sealed then aerated, ammoniated barley in PIII-E3. Barley Moisture Contents at Time of Application (%) 12 18 24 30 36 Control (12%) Time of NH3 Application* (Minutes) 33.0 8.0 7.5 5.0 3.0 -Aeration Time (days) 0** 4.52 4.33 4.28 4.60 4.77 2.30 2 3.31 2.92 2.78 2.65 2.62 2.30 4 3.16 2.76 2.64 2.58 2.56 2.30 7 3.06 2.75 2.58 2.51 2.51 2.30 40 2.71 2.55 2.38 2.41 2.41 2.30 *As determined by the balloon technique described earlier in the Methods. **NH3 barley was removed directly from sealed jars and analyzed by the macro-Kjeldahl technique as described in the Methods. which invariably resulted in moisture rising to the surface of the stored grain allowing for an accelerated loss of NH3. In the present t r i a l , the NH3 retention appeared to be affected by residual moisture in the grain, as the concentration of NH3 remained highest in the treatments with low moisture content throughout the aeration period. Based on the results of this experiment, it would be of interest to conduct a similar experiment using freshly harvested HM barley at varying moisture contents, as opposed to reconstituted barley. An experiment of this nature was not undertaken due to the unavailability of the required materials. However, information from such a study would be useful, under practical conditions, for estimating the storability and feeding value of NH3-treated barley once it had been removed from - 122 -Figure 3. Changes in nitrogen percent of barley reconstituted at varying levels, treated with NHS and aerated over time at room temperature in PIII-E3. Treatment Moisture Percent w CO CD ti c CD O i _ CD CL c O) o Time (Days) - 123 -Figure 4. Changes in moisture content of barley reconstituted at varying levels, treated with NH3 and aerated over time at room temperature in PIII-E3. I I I I I I / I I 0 2 4 6 8 10 ' 20 30 Time (Days) - 124 -hermetic storage. Storing NH3-treated grain non-hermetically does not appear to be an adequate method of preservation, since losses during a p p l i c a t i o n are too great (Mowat et a l . 1981) and r e a p p l i c a t i o n of NH3 i s frequently required ( P e p l i n s k i et a l . 1978). The r e s u l t s from the present experiment tend to suggest that even a f t e r storage in a sealed container, the N H 3-retention of the treated barley a f t e r aeration i s very poor. The N H 3-retention most l i k e l y would have been greater, i f the grain had dried more slowly (Figure 4 ) . However, these r e s u l t s do r e a f f i r m the close r e l a t i o n s h i p between NH3 concentration and moisture content, which i s strengthened further by the rates of NH3 a p p l i c a t i o n for the varying moisture treatments in Table 22. The time of NH3 absorption decreased s u b s t a n t i a l l y as the moisture content of the grain increased. This suggests that the NH3 was most r e a d i l y absorbed by the free-water in the intergranular spaces, since as the l e v e l of free-water decreased so did the rate of absorption. However, the NH3 held by low moisture grain appears to be more t i g h t l y f i x e d than that of high-moisture g r a i n . - 125 -SUMMARY AND CONCLUSIONS In the i n i t i a l phase, high-moisture barley was preserved in four d i f f e r e n t ways (anaerobic, a l k a l i , acid and d r i e d ) , stored for nine months and evaluated in a d i g e s t i b i l i t y and a nitrogen balance t r i a l with pigs and r a t s , r e s p e c t i v e l y . The temperature of the grain was monitored for the f i r s t 3 months of storage. A l k a l i - t r e a t e d barley (32 g NaOH/Kg a i r dry barley) had the highest grain temperature throughout storage with an i n i t i a l value of 33.8°C, (17.8°C above) that of the anaerobic barley. It cannot be stated c o n c l u s i v e l y that NaOH increases DM d i g e s t i b i l i t y i n monogastrics as DM d i g e s t i b i l i t y was only increased s i g n i f i c a n t l y (P < 0.001) in rats and not in pigs. However, the e f f e c t of NaOH on nitrogen d i g e s t i b i l i t y and nitrogen u t i l i z a t i o n i n monogastrics was severe. True nitrogen d i g e s t i b i l i t y was approximately ten and twenty percentage units lower for NaOH-treated barley versus n o n - a l k a l i - t r e a t e d barley for rats and pigs, r e s p e c t i v e l y . The net protein u t i l i z a t i o n (NPU) for r a t s given NaOH-barley was twenty percentage units lower than values for other types of stored grain and untreated g r a i n . There are at l e a s t three reasons for t h i s negative e f f e c t of NaOH on protein u t i l i z a t i o n i n monogastrics which are: (1) racemization of natural L-amino acids to D-enantiomers, (2) formation of synthetic amino acids ( l y s i n o a l a n i n e ) and (3) M a i l l a r d or browning r e a c t i o n . These three f a c t o r s are a l l promoted by high pH and high temperatures. Differences among non - a l k a l i treated barley were i n s i g n i f i c a n t in pigs and s i g n i f i c a n t l y (P < 0.001) greater for anaerobic over acid-treated barley regarding NPU in r a t s . In the second phase, high-moisture barley was harvested and - 126 -preserved i n four d i f f e r e n t ways (high-moisture (HMB), a r t i f i c i a l l y dried (ADB), f i e l d dried (FDB) and reconstituted (RB)) and evaluated i n a d i g e s t i b i l i t y and a nitrogen balance t r i a l with sheep and r a t s . The straws from HMB and FDB were also evaluated i n a d i g e s t i b i l i t y t r i a l with sheep. The straw from HMB was superior regarding apparent DM, OM and nitrogen d i g e s t i b i l i t y by 4.9, 5.1 and 34.3 percentage u n i t s , r e s p e c t i v e l y . The four barley treatments were not s i g n i f i c a n t l y d i f f e r e n t regarding e i t h e r nitrogen d i g e s t i b i l i t y nor retention with sheep. However, with r a t s , true nitrogen d i g e s t i b i l i t y was s i g n i f i -c antly (P < 0.001) higher f o r FDB and ADB than HMB. There was l i t t l e d i f f e r e n c e among the treatments for NPU. The acid detergent f i b r e (ADF) content of the HMB was approximately 11% higher than that of the other treatments. This d i f f e r e n c e contributed to the s i g n i f i c a n t (P < 0.01) increased (= 25%) in ADF d i g e s t i b i l i t y of HMB above FDB and RB. In the l a s t phase, dry barley was reconstituted (RB) and treated with sodium hydroxide (NaOH-RB) and 1 and 3% anhydrous ammonia (1 and 3% NH3-RB) then evaluated i n a d i g e s t i b i l i t y and nitrogen balance t r i a l with sheep and r a t s . Only the 3% NH3-RB s i g n i f i c a n t l y (P < 0.01) improved DM d i g e s t i b i l i t y for sheep. With r a t s , DM d i g e s t i b i l i t y was s i g n i f i c a n t l y (P < 0.001) highest for NaOH-RB and then 1 and 3% NH3-RB and f i n a l l y RB. Nitrogen d i g e s t i b i l i t y was s i g n i f i c a n t l y (P < 0.001) lower for NaOH-RB than the compared treatments with both sheep and r a t s . Percent nitrogen-retention was the same for a l l treatments including NaoH-RB with sheep, but the grams of nitrogen retained by sheep given 1 and 3% NH3-RB increased by approximately 20 and 62% above that for sheep given RB. For r a t s , NPU was s i g n i f i c a n t l y (P < 0.001) - 127 -lower for NaOH-RB, as before i n the f i r s t phase, and NH3 appeared to have no e f f e c t on protein q u a l i t y . Untreated barley was s i g n i f i c a n t l y (P < 0.001) superior than the compared treatements for both BV and NPU with r a t s . In t h i s study, untreated high-moisture barley was, generally, found to have equivalent d i g e s t i b i l i t y and nitrogen u t i l i z a t i o n c o e f f i -c i e n t s as dry barley. Fibre d i g e s t i b i l i t y was superior for HMB in sheep as the f i b r e content of HMB was greater than the compared treatments. However, the botanical compostion of the same HMB indicated that the percentage of fin e s and chaff was only approximately 1.3 percentage u n i t s greater than f i e l d - d r i e d barley. It was also demonstrated, that NaOH severely reduced the protein q u a l i t y of barley for monogastrics but may l i k e l y increase DM d i g e s t i b i -l i t y . Nitrogen-retention was unaffected by NaOH-treated barley for sheep, but an increase i n DM d i g e s t i b i l i t y , as reported by the l i t e r a -ture for ruminants, was not observed with sheep. From the r e s u l t s obtained and those from the l i t e r a t u r e , the optimum l e v e l of NaOH ap p l i c a t i o n appears to be pri m a r i l y dependent on f i b r e content of the grain and the intended use as a feed (e.g. sole component of r a t i o n vs. supplement to roughage based r a t i o n and ruminants vs. monogastrics), rather than simply grain species alone. Therefore, while NaOH-treated barley may be su i t a b l e for ruminants, the lower protein q u a l i t y deters d r a s t i c a l l y from i t s use with monogastrics. Ammonia treatment of barley at 1 and 3% (w/w a i r dry basis) did not appear to negatively a f f e c t the protein q u a l i t y of barley for r a t s , but at the same time u t i l i z a t i o n of NH3 was poor. Conversely, with - 128 -sheep, nitrogen from NH 3-treated barley appeared to be u t i l i z e d as e f f i c i e n t l y as residual nitrogen from the grain. Dry matter d i g e s t i b i -l i t y of NH 3-barley was improved for both the sheep and r a t s . The r e s u l t s from t h i s study combined with those from the l i t e r a t u r e , tend to suggest that the n u t r i t i o n a l value of NH 3-treated barley i s improved for sheep. However, further studies must be conducted to determine the f e a s i b i l i t y of tr e a t i n g and storing grain with NH3 , regarding i t s v o l a t i l e nature, before NH3 could possibly be recommended as a preserv-ing agent for grain given to ruminants. Also, further work must be ca r r i e d out with monogastrics to measure the p a l a t a b i l i t y and feeding values of NH 3-treated grain. The long term e f f e c t s of ammoniated feed on the animal must also be known before NH3 can be recommended as a method of preserving high-moisture grain for monogastrics. - 129 -BIBLIOGRAPHY Anderson, G.D., Berger, L.L. and Fahey, G.C., Or. 1981. A l k a l i treatment of cereal grains. I I . Digestion, ruminal measurements and feedlot performance. 0. Anim. S c i . , 52: 144-149. Anderson, O.A. Babbit, 0.0. and Meredith, W.O.S. 1943. The e f f e c t of temperature d i f f e r e n t i a l on the moisture content of stored wheat. Can. 0. Res. C, 21: 297-306. Association of O f f i c i a l A n a l y t i c a l Chemists. 1980. O f f i c i a l methods of analysis 13th ed. Association of O f f i c i a l A n a l y t i c a l Chemists, Washington, D.C. Austin, 0. 1967. Urea t o x i c i t y and i t s prevention. In: Urea as a protein supplement. 1st e d i t i o n . Ed. Briggs, M.H. Pergamon Press, Oxford, New York. pp. 173-184. Aw-Yong, L.M. and Beames, R.M. 1975. Threonine as the second-limiting amino acid in Peace River barley for growing-finishing pigs and growing r a t s . Can. 0. Anim. S c i . 55: 765-783. Ayerst, G. 1965. Determination of water a c t i v i t y of some hygroscopic food materials by a dew point method. 0. S c i . Food A g r i . , 16: 71-78. Banks, H.0. and Annis, P.C. 1980. Experimental and commercial modified atmosphere treatments of stored grain in A u s t r a l i a . In: Controlled atmospheric storage of grains. Ed. Shejbal, 0. E l s e v i e r S c i e n t i f i c Publishing Co. Oxford, New York. pp. 207-224. Barnes, B.0. and Orskov, E.R. 1981. U t i l i z a t i o n of a l k a l i - t r e a t e d g r a i n . 2. U t i l i z a t i o n by steers on di e t s based on hay or straw and mixed with either NaOH-treated or r o l l e d barley. Anim. Feed S c i . Tech., 6: 347-354. Barry, T.N. 1976a. The effectiveness of formaldehyde treatment i n protecting dietary protein from rumen microbial degradation. Proc. N u t r i . S o c , 35: 221-229. Barry, T.N. 1976b. Evaluation of formaldehyde-treated lucerne hay for protecting protein from ruminal degradation, and for increasing nitrogen retention, wool growth, liveweight gain and voluntary intake when fed to young sheep. 0. A g r i . S c i . , U.K., 86: 379-392. Barton, N.0. and McLaughlin, O.W. 1976. E f f e c t s of formaldehyde treatment on high q u a l i t y pasture hay on i t s u t i l i z a t i o n by weaner sheep. Au s t r a l . 0. Exp. A g r i . Anim. Husb., 16: 661-667. Bayley, H.S. and Holmes, O.H.G. 1972. Digestion of acid preserved corn by pigs. 0. Anim. S c i . , 35: 1102 (Abstr.). - 130 -Beames, R.M. 1960. A note on the preservation of a solution of molasses and urea i n water. Queensland 3. A g r i . S c i . , 17: 205-206. Berg, C P . 1959. U t i l i z a t i o n of D-amino acids. In: Protein and amino acid n u t r i t i o n . Ed. Albanese, A.A. Academic Press, New York, N.Y. pp. 57-96. Berger, L.L., Anderson, CO. and Fahey, G.C., 3r. 1981. A l k a l i treatment of cereal grains. I. In s i t u and in v i t r o evaluation. 3. Anim. S c i . , 52: 138-143. B j e r r i n g , 3.H., Graig, M. and Halm, 3.D. 1975. U.B.C. BMD 10V Analysis of variance/covariance. University of B r i t i s h Columbia Computing Centre, Vancouver. Borhami, B.E.A. and Sundstol, F. 1982. Studies on ammonia-treated straw. I. The e f f e c t s of type and l e v e l of ammonia, moisture content and treatment time on the d i g e s t i b i l i t y in v i t r o and enzyme soluble organic matter of oat straw. Anim. Feed S c i . Tech., 7:45-51. Borhami, B.E.A., Sundstol, F. and Garmo, T.H. 1982. Studies of ammonia-treated straw. 2. Fixation of ammonia in treated straw by spraying with acids. Anim. Feed. S c i . Tech., 7: 53-59. Bothast, R.3., Lancaster, E.B. and Hesseltine, C.W. 1973. Ammonia k i l l s spoilage molds in corn. 3. Dairy S c i . , 56: 241-245. Bothast, R.3., Adams, G.H., H a t f i e l d , E.E. and Lancaster, E.B. 1975. Preservation of high moisture corn: a microb i o l o g i c a l evaluation. 3. Dairy S c i . , 58: 386-391. Bothast, R.3., Black, L.3., Wilson, L.L. and H a t f i e l d , E.E. 1978. Methylene-bis-propionate preservation of high-moisture corn. 3. Anim. S c i . , 46: 484-489. Bowland, 3.P., Young, B.A. and M i l l i g a n , L.P. 1971. Influence of dietary v o l a t i l e f a t t y acid mixtures on performance and on fat composition of growing pigs. Can. 3. Anim. S c i . , 51: 89-94. Brenchley, W.E. 1912. The development of the grain of barley. Ann. Botany. 26: 903-928. Briggs, D.E. 1978. Barley. Halsted Press a d i v i s i o n of Dohn Wiley and Sons, Inc., New York, Chapter 10. B r i t t , D.G. and Huber, 3.T. 1976. Preservation and annual performance of high-moisture corn treated with ammonia or propionic acid. 3. Dairy S c i . , 59: 668-674. Brooker, D.B., Bakker-Arkema, F.W. and H a l l , C.W. 1974. P r i n c i p l e s of grain drying. In: Drying cereal grains. Avi Publishing, Connecticut, pp. 1-21. - 131 -Burmeister, H.R., Hartman, P.A. and Saul, R.A. 1966. Microbiology of ensiled high-moisture corn. Appl. M i c r o b i o l . , 14: 31-34. B u r r e l l , N.3. and Laundon, 3.H.3. 1967. Grain cooling studies. 1. Observations during a large scale r e f r i g e r a t i o n test on damp grain. 3. Stored Prod. Res., 3: 125-144. B u r r e l l , N.3. and Havers, S.3. 1970. Survey of some farm stores of ven t i l a t e d grain. 3. S c i . Food Agri., 21: 9, 458-464. B u r r e l l , N.3. 1974. C h i l l i n g . In: Storage of cereal grains and the i r products. 2nd ed., Christensen, CM., Am. Assoc. Cereal Chemists, St. Paul, pp. 420-453. Busta, F.F., Smith, L.B. and Christensen, CM. 1980. Microbiology of controlled atmosphere storage of grains. In: Controlled atmosphere storage of grains. Ed. Shejbah, 3. E l s e v i e r S c i e n t i f i c Publishing Co., pp. 121-132. Carter, E.P. 1950. The role of fungi in the heating of moist wheat. U.S. dep. Ag r i . C i r c , 838, p. 26. Christensen, CM. and Gordon, D.R. 1948. The mold f l o r a of stored wheat and corn and i t s r e l a t i o n to heating of moist grain. Cereal Chem. 25: 42-51. Christensen, CM. and Kaufmann, H.H. 1969. Grain storage. Minneapolis: University of Minnesota Press. Christensen, CM. and Kaufmann, H.H. 1974. M i c r o f l o r a . In: Storage of cereal grains and t h e i r products. (2nd edition) ed. Christensen, CM. Ammerican Assoc. of Cereal-Chemists, Inc., pp. 158-193. Cole, D.3.A., Brooks, P.H., English, P.R., Livingstone, R.M. and Luscombe, 3.R. 1975. P r i o p i o n i c acid-treated barley i n die t s for bacon pigs. Amin. Prod., 21: 295-302. Cotton, R.T. and Wilbur, D.A. 1974. Insects. In: Storage of cereal grains and t h e i r products. 2nd ed., Ed. Christensen, CM. Am. Assoc. Cereal Chemists. Inc., pp. 194-231. Church, D.C. and Champe, K.A. 1980. D i g e s t i b i l i t y of hydroxide-treated anual ryegrass straw. 3. Anim. S c i . , 51: 20-24. Darsie, M.L., E l l i o t t , C. and Peirce, G.3. 1914. A study of the germinating power of seeds. Bot. Gaz. (Chicago), 58: 101-136. Davidson, 3., Mcintosh, A.D. and Milne, E. 1982. Note on lysinoalanine content of a l k a l i - t r e a t e d barley. Anim. Feed S c i . Tech., 7: 217-220. De Groot, A.P. and Slump, P. 1969. E f f e c t s of severe a l k a l i treatment of proteins on amino acid composition and n u t r i t i v e value. 3. Nutr., 98: 45-56. - 132 -De Groot, A.P., Slump, P. Van Beek, L. and Feron, V.3. 1976a. Severe a l k a l i treatment of p r o t e i n . In: Evaluation of protein for humans, fed. Bodwell, C.E Avi Publishing, Connecticut, pp. 270-283. De Groot, A.P. Slump, P., Feron, V.3. and Van Beek, L. 1976b. E f f e c t s of a l k a l i - t r e a t e d proteins: feeding studies with free and protein-bound lysinoalanine i n rats and other animals. 3. Nutr., 106: 1527-1538. Dexter, S.T., Chaves, A.M. and Edje, O.T. 1969. Drying or amaerobically preserving small l o t s of grain for seed and food. Agron. 3., 61: 913-919. Disney, R.W. 1954. The s p e c i f i c heat of some cereal grains. Cereal Chem., 31: 229-239. Dodds, M.E. and Dew, D.A. 1958. The e f f e c t s of swathing at d i f f e r e n t stages of maturity upon the bushel weight and y i e l d of barley. Can. 3. of P i n t . S c i . , 38: 495-504. Draper, H.H., Bergan, O.G., Chin, M., Csallamy, A.S. and Boaro, A.V. 1964. A further study of the s p e c i f i c i t y of the vitamin E reguirement for reproduction. 3. N u t r i . , 84: 395-400. Eggum, B.0. 1973. A study of c e r t a i n f a c t o r s i n f l u e n c i n g protein u t i l i z a t i o n in rat and pigs. N a t l . Inst. Anim. S c i . Copenhagen. Beretn., 406: 173 pp. Eggum, B.0. and Beames, R.M. 1981. Laboratory animals as models for domestic animals. In: World animal science. E l s e i v e r S c i e n t i f i c P u b lishing Co., Vol. 35 ( i n press). Evered, D.F. 1981. Advances in amino acid metabolism i n mammals. Biochem. Soc. Transact., 9: 159-169. Feeney, R.E. 1975. Chemical changes in food proteins. In: Evaluation of proteins for humans. Ed. Bodwell, C.E. Avi Publishing, Connecticut, pp. 233-253. Forbes, 3.L. 1965. Some observations on the hermetic storage of undried barley and i t s use i n pig-feeding. Agr. Progress, 40: 55-67. Forsyth, 3.G., Mowat, D.N. and Stone, 3.B. 1972. Feeding value for beef and dairy c a t t l e of high-moisture corn preserved with propionic a c i d . Can. 3. Anim. S c i . , 52: 73-79. Foster, G.H., Kaler, H.A. and Whistler, R.L. 1955. E f f e c t s of corn on storage i n a i r t i g h t bins. 3. A g r i . Food Chem., 3: 682-686. Frape, D.L., Wolf, K.L., Wilkinson, 3. and Chubb, L.G. 1968. Modif i c a t i o n to S h i n f i e l d Metabolism c r a t e . 3. Inst. Anim. Tech., 19: 61-64. - 133 -Frape, D.L., Wilkinson, 3. and Chubb, L.G. 1968b. E f f e c t of processing barley and of delayed concentrate feeding on growth and nutrient balance in growing pigs and the e f f e c t of processing barley on the apparent d i g e s t i b i l i t y of pregnant sows. 3. Anim. S c i . , 27: 1313-1318. Friedman, M. 1979. Alkali-induced lysinoalanine formation i n s t r u c t u r a l l y d i f f e r e n t proteins. In: Func t i o n a l i t y and protein st r u c t u r e . Ed. Pour-El, A. American Chemical Society, Wash., D.C, pp. 225-235. Fulton, W.R., Klopfenstein, T.3. and B r i t t o n , R.A. 1979. Adaption to high concentrate d i e t s by beef c a t t l e . 1. Adaption to corn and wheat d i e t s . Can. 3. Anim. S c i . , 49: 775. Gallup, W.D., Pope, L.S. and Whiehair, C K. 1953. Oklahoma A g r i . Expt. Sta. B u l l . B-409. Georing, H.K. and Gordon, C H . 1973. Chemical aids to preservation of high-moisture feeds. 3. Dairy S c i . , 56: 1347-1351. Gershon, H. and Parmegiani, R. 1967. Organic f l u o r i n e compounds. I I . Synthesis and antifungal properties of 2-fluoro f a t t y acids. 3. Med. Chem. 10:186-188. Greenhalgh, 3.F.D. and P i r i e , R. 1979. A l k a l i treatment of barley straw, hay, dried grass, bean straw and whole crop oats. Anim. Prod., 28: 431 ( a b s t r . ) . Harlan, H.V. 1920. The d a i l y development of kernels of Hannchan barley from flowering to maturity at Aberdeen, Idaho. 3. A g r i . Res., 19: 393-429. Harpster, H.W., Long, T.A. and Wilson, L.L. 1975. A n u t r i t i v e evaluation of dried, high-moisture and acid-treated corn and sorghum grains for sheep. 3. Anim. S c i . , 41: 1124-1133. Haward, W., Hunt, W.H. and Pixton, S.W. 1974. Moisture - i t s s i g n i f i c a n c e , behavior and measurement. In: Storage of cereal grains and t h e i r products. (2nd ed.) Ed. Christensen, CM. Am. Assoc. Cereal Chemists, St. Paul, pp. 1-55. Hayashi, R. and Kameda, I. 1980. Racemization of amino acid residues during alkali-treatment of protein and i t s e f f e c t on pepsin d i g e s t i b i l i t y . Agric. B i o l . Chem., 44: 891-895. Hayashi, T. and Naniki, M. 1981. On the mechanism of free r a d i c a l formation during browing reaction of sugars with amino compounds. Agric. B i o l . Chem., 45: 933-939. Holman, L.E. and Carter, D.G. 1952. Soybean storage i n farm type bins. Univ. I l l i n o i s Agr. Expt. Sta. B u l l . , 533: 451-495. -. 134 -Holmes, 3.W., Clark, H.R. and Fleakston, F.A. 1972. Prevention of corrosive attack on galvanized s t e e l by acid treated feed g r a i n . Annual meeting of Can. Soc. Agric. Eng., Charlottetown, P.E.I. 3une 26. As ci t e d by Dones et a l . (1974). Holmes, 3.H.G., Baylay, H.S. and Stevenson, K.R. 1973. Ef f e c t of acid preservation of corn on the digestion of nutrients by the pig. Proc. 9th Ann. N u t r i . Conf. Feed Mfgs, Toronto. A p r i l 25, p. 50. As c i t e d by Oones et a l . (1974). Horton, G.M.3., Nicholson, H.H. and Christensen, D.A. 1982. Ammonia and sodium hydroxide treatment of wheat straws in diets for fattening steers. Anim. Feed S c i . Tech., 7: 1-10. Howe, R.W. 1965. A summary of estimates of optimal and minimal conditions for population increase of stored product i n s e c t s . 3. Stored Prod. Res., 1: 177-184. Huitson, 3.3. 1968. Cereal preservation with propionic acid. Process Biochem., 3: 31-32. Hummel, B.C.W., Cuendet, L.S., Christensen, CM. and Geddes, W.F. 1954. Grain storage studies. XIII. Comparative changes in r e s p i r a t i o n , v i a b i l i t y and chemical composition of mold-free and mold-contaminated wheat upon storage. Cereal Chem., 31: 143-150. Hyde, M.B. 1965. P r i n c i p l e s of wet grain conservation. 3. Proc. Inst. Agr. Eng., 21: 75-82. Hyde, M.B.- 1970. Storage t r i a l s with moist barley and f i e l d beams i n polyvi n y l chloride and butyl rubber s i l o s . Proc. 4th Int. Colloquium on P l a s t i c s in Agri c u l t u r e , P a r i s . As c i t e d by Hyde (1974). Hyde, M.B. 1974. A i r t i g h t storage. In: Storage of cereal grains and t h e i r products. 2nd ed., Ed. Christensen, CM. Am. Assoc. Cereal Chemists, St. Paul, pp. 383-419. Hyde, M.B. and Burrel, N.3. 1969. Control of i n f e s t a t i o n instored grain by a i r t i g h t storage or by cooling. Proc. 5th B r i t i s h I n s e c t i c i d e s and Fungicides Conference, Brighton. Hyde, M.B. and Burrel, N.3. 1973. Some recent aspects of grain storage technology. In: Grain storage: Part of a system. Ed. Sinha, R.N. and Muir, W.E., Avi Publishing, Connecticut, pp. 313-342. Hyde, M.B. and Oxley, T.A. 1955. Experiments on a i r t i g h t storage of damp grain. (1) Introduction, e f f e c t on the grain and the intergranular atmosphere. Ann. Appl. B i o l . , 48: 687. I n g a l l s , 3.R., Clark, K.W. and Sharma, H.R. 1974. Acid-treated high-moisture barley for dairy cows. Can. 3. Anim. S c i . , 54: 205-209. - 135 -Isaacs, G.W. 1962. Preservation of high-moisture grain in oxygen-free storages. Farm S c i . Day, Purdue U n i v e r s i t y . Dames, C. 1980. Economic, s o c i a l and p o l i t i c a l implications of crop losses; a h o l i s t i c framework for loss assessment in a g r i c u l t u r a l systems. In: Crop loss assessment. Proceedings of E.C. Stokman Commemorative Symposium. Miscellaneous publications 7, A g r i c u l t r u a l Experiment Station, University of Minnesota. 3ay, E. 1980. Low temperatures: e f f e c t s on control of S i t o p h i l u s oryzae (L.) with modified atmospheres. In: Controlled atmosphere storage of grains. Ed. Shejbal, 3. E l s e v i e r S c i e n t i f i c Publishing Co., pp. 65-72. Oayasuriya, M.C.N, and Owen, E. 1975. Sodium hydroxide treatment of barley straw; e f f e c t of volume and concentration of solution on d i g e s t i b i l i t y and intake by sheep. Anim. Prod., 21: 313-322. Ooffe, A.Z. 1962. B i o l o g i c a l properties of some t o x i c fungi i s o l a t e d from overwintered c e r e a l s . Mycopath. Mycol. Appl., 16: 201-221. Oones, G.M., Donefer, E. and E l l i o t , 3.1. 1970. Feeding value for dairy c a t t l e and pigs of high-moisture corn preserved with propionic a c i d . Can. 0. Anim. S c i . , 50: 483-489. Oones, G.M. 1970. Preservation of high-moisture corn with v o l a t i l e f a t t y acids. Can. 0. Anim. S c i . , 50: 739-741. Oones, G.M. and Larsen, R.E. 1974. Changes i n estimates of s i l a g e dry matter intake or apparent d i g e s t i b i l i t y as affected by methods of DM determination. Can. 0. Anim. S c i . , 54: 145-148. Oones, G.M., Mowat, D.N., E l l i o t , 0.1. and Moran, E.T., Or. 1974. Organic acid preservation of high moisture corn and other grains and the n u t r i t i v e value: A review. Can. 0. Anim. S c i . , 54: 499-517. Oordan, O.W., Weatherup, S.T.C. 1976. The e f f e c t of formalin used as a preservative, on the n u t r i t i v e value of cows' milk diet fed to early weaned pigs. Record of Agric. Res., 24: 45-48. Kamel, A.H. 1980. Underground storage in some Arab countries. In: Controlled atmosphere storage of grains. Ed. Shejbal, 0. E l s e v i e r S c i e n t i f i c Publishing Co., pp. 25-38. Kare l , M., Fennema, O.R. and Lund, D.B. 1975. P r i n c i p l e s of food science. Part I I . Physical p r i n c i p l e s of food preservation. Ed. Fennema, O.R., and Marcel Dekker, Inc., New York. Kiangi, E.M.I, and Kategite, O.A. 1981. D i f f e r e n t sources of ammonia for improving the n u t r i t i v e value of low quality roughages. Anim. Feed S c i . Tech., 6: 377-386. K i e s e l , A. 1913. Recherches sur T a c t i o n de divers acides et sels acides sur le developpement de' 1'Aspergillus Niger. Ann. Inst. Pasteur, 27: 391-420. As c i t e d by Oones et a l . (1974). - 136 -K i r i l e n k o , O.A. Yakovenko, V.A., Lebedinskii, V.G. and Zvyaginstev, B.G. 1977. Spontaneous heating of dry wheat during storage. N u t r i . Absts. and Rev. Series B, 47: 3. Klopfenstein, 3.G., Krause, V.E., Gones, M.3. and Woods, W. 1972. Chemical treatment of low-quality roughages. 3. Anim. S c i . , 35: 418. Klopfenstein, G.G. 1978. Chemical treatment of crop residues. G. Anim. S c i . , 46: 841-848. Koehler, B. 1938. Fungus growth in shelled corn as affected by moisture. G. Agr. Res., 56: 291-307. Koenig, R.F., Robertson, D.W. and Dickson, H.D. 1965. E f f e c t s of time of swathing on malting barley q u a l i t y . Crop Science, 5: 5. K r a l l , G.L. and Thomas, 0.0. 1964. High-moisture barley as a feed grain. Mont. A g r i . Exp. Sta., 8th Cattle Feeders Day, Report No. 14. K r a l l , G.L. 1972. High-moisture barley harvesting, storing and feeding. Montana Agric. Exp. Stn. B u l l . 625, 45 pp. Laksesvela, B. and Slagsvold, P. 1980. A note on the d i g e s t i b i l i t y in lambs of whole, dry barley treated with ammonia. Anim. Prod., 30: 437-439. Laksesvela, B. 1981. A note on the use of whole moist barley treated with ammonia as a feed supplement for sheep. Anim. Prod., 32: 231-233. Lancaster, E.B., H a l l , G.E. and Brekke, O.L. 1974. Treating corn with ammonia. Behavior of the corn-water-ammonia system. Trans. ASAE, 73: 311-338. Larsen, H.3., Gorgensen, N.A., Barrington, G.P. and Niedermeiner, R.P. 1972. E f f e c t of organic acids on preservation and a c c e p t a b i l i t y of high-moisture corn. G. Dairy S c i . , 55: 685 (Abstr.). Lazor, M., Zakula, S., D e l i c and Zdravkovic, R. 1978. E f f e c t of l u p r o s i l and l u p r o s i l - s a l z on the quality and e f f e c t of mixed feeds for fattening b u l l s . Nutr. Abstr. Rev. Ser. B., 48: 201. Livingstone, R.M., Denerley, H., Stewart, C S . and E l s l e y , F.W.H. 1971. Moist barley for growing pigs: Some e f f e c t s of storage method and processing. Anim. Prod., 13: 547-556. Lloyd, L.E., McDonald, B.E. and Crompton, E.W. 1978. E s s e n t i a l macroelements. In: Fundamental of n u t r i t i o n (2 ed.). W.H. Freeman and Co., Chpt. 17, pp. 224. Low, S.G. and Kellaway, R.C. The u t i l i z a t i o n of N H 3-treated whole wheat grain by young steers. Submitted to Anim. Feed S c i . Tech. - 137 -Marloth, R.H. 1931. The influence of hydrogen-ion concentration and of sodium bicarbonate and related substances on P e n i c i l l i u m italicum and P. digitatum. Phytopathology 21: 169-198. Marx, G.O. 1978. Feeding: In northern areas, high-moisture barley i s a p r a c t i c a l feed. Hoard's Diary Man. May 25, pp. 688-689. Matsushima, O.K. and Stenquist, H.3. 1967. Reconstituted ensiled and flaked corn for beef c a t t l e . 0. Anim. S c i . , 26: 925 (Abstr.). Maynard, L.A. and L o o s l i , O.K. 1969. Animal n u t r i t i o n . 6th ed. McGraw-Hill, Inc., pp. 260. McGinty, D.D., Drewer, L.H. and Riggs, O.K. 1967. D i g e s t i b i l i t y of dry and reconstituted grain sorghum by beef c a t t l e . Beef c a t t l e research report in Texas. Rep. No. PR 2-424. Texas A and m University, Tex. McKnight, D.M., Macleod, G.K., Buchanan-Smith, O.G. and Mowat, D.N. 1973. U t i l i z a t i o n of ensiled or acid-treated high-moisute shelled corn by c a t t l e . Can. 0. Anim. S c i . , 53: 491-496. McLean, D.M. 1933. The e f f e c t of harvesting at d i f f e r e n t stages of maturity upon the y i e l d and chemical composition of barley. S c i . A g r i . , 13: 698-713. McNiell, O.W., Rather, G.O. and Riggs, O.K. 1971. Ruminal and post-ruminal carbohydrate u t i l i z a t i o n in steers fed processed sorghum grain. 3. Can. Anim. S c i . , 33: 1371-1374. Mederick, F.M., Helm, 0. and Salmon, D. 1982. High-moisture grain production research. Crop Research, Lacombe, Alberta Agriculture, pp. 23. Meiering, A.G., Bakker-Arkema, F.W. and Bickert, W.G. 1966. Short time sealed storage of high-moisture sealed grains. Mich. A g r i . Exp. Sta. Quart. B u l l . , 48: 465-470. Merck Index. 1976. 9th ed. Edited by Windholz, M. Published by Merck and Co., Radway, N.0. M e r r i l l , W.G. 1971. Feeding high-moisture grain s i l a g e s . Proc. Int. Silage Res. Conf., Washington, D.C, pp. 156-219. As cited by Oones et a l . (197*0 . Michelognoli, A. 1980. Pneumatically formed reinforced concrete domes for grain storage f a c i l i t i e s , b u i l t with B i n i s h e l l s technology. In: Controlled atmosphere storage of grains. Ed. Shejbal, 0. E l s i v i e r S c i e n t i f i c Publishing Co., Oxford, New York. pp. 475-486. Ministry of Agriculture, F i s h e r i e s and Food. 1970. Storage of high-moisture grain using preservative acids. Great B r i t a i n , Short term l e a f l e t , 100: 1-7. - 138 -M i t c h e l l , R.E. 1972. Moulds and mycotoxins - How EPA looks at organic acids as grain preservatives. Farm Tech. Agrifieldman, Willoughby, Ohio, pp. 64-66. Montgomery, R.R., Nofsinger, G.W. and Bothast, R.3. 1980. Preservation of high-moisture maize - A comparison of gaseous and l i q u i d anhydrous ammonia with methylene-bis-propionate. Anim. Feed S c i . Tech., 5: 337-345. Moore-Lander, E. 1972. Fundamentals of Fungi. Pentice-Hall, Inc., pp. 147-183. Moran, E.T., 3r., Carlson, H.C. and P e t t i t , 3.R. 1974a. Vitamin E-selenium deficiency in the duck aggravated by the use of high-moisture corn and moulding p r i o r to preservation. Avaian Diseases, 18: 4, 536-543. Moran, E.T., Or., Longworth, D.M. and Carlson, H.C. 1974b. High-moisture corn for the b r o i l e r chicken and a spoilage provoked vitamin E-selenium d e f i c i e n c y . Feedstuffs, 46: 27-30. Morris, P.Y. and Mowat, D.M. 1980. N u t r i t i v e of ground and/or ammoiniated corn stover. Can. 3. Anim. S c i . , 60: 327-336. Mortimer, C.E. 1971. Chemistry, a conceptual approach (2nd ed.). L i t t o n Educational Publishing, Inc. pp. 644. Mowat, D.N. and Ololade, B.G. 1970. E f f e c t of l e v e l of sodium hydroxide treatment on d i g e s t i b i l i t y and voluntary intake of straw. Can. Soc. Anim. Produc. Proc. pp. 35 (Abstr.). Mowat, D.N., McCaughey, P. and Macleod, G.K. 1981. Ammonia or urea treatment of whole high moisture corn. Can. 3. Anim. S c i . , 61: 703-711. Mueller, 3.P., Kjelgaard, W.L., Anderson, P.M., Hoffman, L.D., Washko, 3.B., Long, T.A. and Wilson, L.L. 1976. Chemical preservation of high-moisture hay. Progress Report, Pensylvania State U n i v e r s i t y , 359, pp. 8. Muir, W.E. and Wallace. 1971. Storage of high-moisture grain i n an a i r t i g h t butyl rubber bin. Can. Agr. Eng., 13: 29-31. Muir, W.E. 1973. Temperature and moisture in grain storages. In: Grain storage: Part of a system. Ed. Sinha, R.N. and Muir, W.E. Avi Publishing Connecticut, pp. 270-283. Navarro, S. and Calderon, M. 1980. Integrated approach to the use of con t r o l l e d atmospheres for is e c t control in grain storage. In: Controlled atmospher storage of grains. Ed. Shejbal. 3. E l s e v i e r S c i e n t i f i c Publishing Co, pp. 73-78. - 139 -Nelson, L.R., Cummins, D.G., Harris, H.B. and Calvert, G.V. 1972. Grain preservatives for storage of high-moisture grain. Res. Report, College of A g r i c , Experiments Stations, University of Georgia, 129, 1-10. Nelson, L.R., Cummins, D.G., Harris, H.B. and Baird, D.M. 1973. Storage of high-moisture grain sorghum treated with propionic acid. Agron. 3., 65: 423-425. N i k i t i n s k i i , Ya Ya. 1955. Storage of damp whet grains i n an atmosphere of carbon dioxide gas in an experimental s i l o . Trudy Vses. Nauch. I s s l e d . Inst. Zerna 30:5-12. As c i t e d by Hyde (1974). Northwest School of Ag r i c u l t u r e , U. of Minn. 1961. Station does research on high-moisture barley. Northwest School Quarterly, Vol. XLV, No. 2. Ohta, K., Kiyomiya, A., Koyama, N. and Nosoh, Y. 1975. The bases of the a l k a l o p h i l i c property of a species of B a c i l l u s . 3. General Microbiology, 86:259-266. O j i , U.I. and Mowat, D.M. 1979. N u t r i t i v e value of thermoammoniated and steam-treated maize stover. 1. Intake, d i g e s t i b i l i t y and nitrogen retention. Anim. Feed S c i . Tech., 4:177-186. Orskov, E.R., Mahrez, A.Z. and Smart R.I. 1974. A method of including urea i n whole grain. 3. Ag r i : S c i . Camb., 83:299-362. Orskov, E.R. and Greenhalgh 3.F.O. 1977. A l k a l i treatment as a method of processing whole grain for c a t t l e , A g r i . S c i . Camb., 89:253-255. Orskov, E.R. and Macdearmid, A. 1978. U t i l i z a t i o n of a l k a l i - t r e a t e d grain by c a t t l e . Anim. Prod., 26:401-402 (Abstr.). Orskov, E.R., Stewart, C S . and Greenhalgh 3.F.D. 1979a. The e f f e c t of sodium hydroxide and urea on a some storage properties of moist grain. 3. A g r i c S c i . , 92:185-188. Orskov, E.R., Grubb, D.A. and S t i r t o n , R. 1979b. "The e f f e c t of dry-matter concentration and preservation method of whole barley on feed u t i l i z a t i o n by early-weaned lambs. Anim. Prod., 28:431-432 (Abstr.) Orskov, E.R., Macdearmid, A., Barnes, B.3., Grubb, D.A. and Lukins, B.A. 1979c E f f e c t of sodium hydroxide treatment on d i g e s t i b i l i t y of oats, barley, wheat and maize and on u t i l i z a t i o n of sodium hydroxide oats and barley by lambs and steers. Anim. Prod., 28:432 (Abstr.). Orskov, E.R., Barnes, B.3. and Lukins, B.A. 1980. A note on the e f f e c t of d i f f e r e n t amounts of NaOH appl i c a t i o n on d i g e s t i b i l i t y by c a t t l e of barley, oats, wheat and maize. 3. A g r i . S c i . Camb., 94:271-273. - 140 -Orskov, E.R., Macdearmid, A., Grubb, D.A. and Innes G.M. 1981a. U t i l i z a t i o n of a l k a l i - t r e a t e d grain. 1. A l k a l i - t r e a t e d grain in complete diets for steers and lambs. Anim. Feed S c i . Tech., 6: 273-283. Orskov, E.R., Barnes, B.3., Macdearmid, A., Williams, P.E.V. and Innes, G.M. 1981b. U t i l i z a t i o n of a l k a l i - t r e a t e d grain. 3. U t i l i z a t i o n by steers of NaOH-treated and r o l l e d barley in silage-based d i e t s . Anim. Feed S c i . Tech., 6: 355-365. Otterby, D.E. and Murphy, 3.M. 1971. Acid and urea additions to high-moisture shelled corn at e n s i l i n g . 3. Dairy S c i . , 54:771 (Abstr.). Oxley, T.A. 1948. The s c i e n t i f i c p r i n c i p l e s of grain storage. Northern Pub. Co. Liverpool, England. 108 pp. P e p l i n s k i , A.3., Brekke, D.L., Bothast, R.3. and Black, L.T. 1978. High moisture corn - an extended preservation t r i a l with ammonia. Transact. ASAE: 773- 781. Perez-Aleman, S., Dempster, D.S., English, P.R. and Topps, 3.H. 1971. Moist barley preserved with acid in the diet of the growing pig. Anim. Prod., 13: 271-277. Peterson, A., Schlegel, V., Hummel, B., Cuendet, L.S., Geddes, W.F. and Christensen, CM. 1956. Grain storage studies. XXII. Influence of oxygen and carbon dioxide concentrations on mould growth and grain d e t e r i o r a t i o n . Cereal Chem., 33: 53-66. Pienaar, 3.P. and Renton K.A. 1980. The e f f e c t of formalin treatment on n u t r i t i v e value of sorghum grain with a high tannin content. S. A f r . 3. Anim. S c i . , 10: 27-29. Plasto, A.W. 1971. High-moisture grain - a feedlot r a t i o n . Queensland A g r i . 3., 97: 419-422. Pratt, C , Promersberger, W.3., Watson, C.A. and Buchanan, M.C 1961. Storing high-moisture barley i n North Dakota. Proceedings Am. Soc. of A g r i . Eng., Paper No. 61-425. Rannfelt, C. 1980. Controlled atmosphere grain storage in China. Ed. Shejbal, 3. E l s i e v e r S c i e n t i f i c Publishing Co. Richardson, L.R., Cannon, M.L. and Pierce, K.R. 1963. Amino acid deficiency in diets containing mouldy ingredients. Proc. Fedn. Am. Socs. Exp. B i o l . , 22: 201. As c i t e d by Livingstone et a l . (1971). Roberts, E.H. 1960. The v i a b i l i t y of cereal seed in r e l a t i o n to temperature and moisture. Ann. Botany (London), 24: 12-31. Sanderson, 3., Wall, 3.S., Donaldson, G.L. and Cavins, Y.F. 1981. E f f e c t of a l k a l i n e processing of corn on i t s amino acids. Cereal Chem., 55: 204-213. - 141 -Saunders, R.M. and Hautala, E. 1979. Relationships among crude f i b r e , neutral detergent f i b r e , and in vivo (rats) dietary f i b r e i n wheat foods. Am. 3. C l i n . Nutr., 32: 1188-1191. Sc h a l l e r , D. 1977. Analysis of dietary f i b r e . Food product development. November, pp. 70-72. Scott, P.M. 1973. Mycotoxins in stored grain, feeds and other cereal products. In: Grain storage: Part of a system. Ed. Sinha, R.N. and Muir, W.E. Avi Publishing, Connecticut, pp. 343-366. Semeniuk, G. 1955. M i c r o f l o r a . In: Storage of cereal grains and t h e i r products. Ed. Anderson, 3.A. and Alcock, A.W. Am. Assoc. Cereal Chemists, St. Paul. S e r a f i n i , M., Fabbri, A.A., Shejbal, 3., F a n e l l i , C , Di Maggio, D. and Rambelli. 1980. Influence of nitrogen on the growth of some storage fungi on moist wheat In: Controlled atmosphere storage of grain. Ed. Shejbal, 3. E l s i v i e r S c i e n t i f i c Publishing, Co. Oxford, New York. pp. 157-172. Sharkey, M.F., Hodge, R.W., Davis, I.F. and Bogdanovic, B. 1976. Some ef f e c t s of formaldehyde treatment of hay and s i l a g e and l e v e l of barley intake on the production of cross bred lambs fed in pens. A u s t r a l . 3. Exp. Agric. Anim. Husb., 16: 452-457. Shvetsova, V.A. and Sosedov, N.I. 1958. Biochemical changes during prolonged hermetic storage of wheat. Biokhimiya Zerna. 4: 229-240. As c i t e d by Hyde (1974). Sinha, 3. 1964. E f f e c t of low temperatures on the s u r v i v a l of some steed product mites. Acarologia, 6: 336-341. Sinha, R.N. 1973. I n t e r r e l a t i o n s of physical, chemical and b i o l o g i c a l variables in the d e t e r i o r a t i o n of stored grains. In: Grain storage: Part of a system. Ed. Sinha, R.N. and Muir, W.E., Avi Publishing, Connecticut, pp. 15-48. Spurgeon, D. 1976. A systems approach to post harvest technology. In: Hidden harvest. International Development Research Centre. Ottawa, Canada, pp. 36. Sriskandarajah, N., Ashwood, A. and Kellaway, R.C. 1980. E f f e c t s of r o l l i n g and a l k a l i treatment of barley grain supplements on forage intake and u t i l i z a t i o n by steers and l a c t a t i n g cows. 3. Agric. S c i . , Camb., 95: 555-562. Srivastava, V.K. and Mowat, D.N. 1980. Preservation and processing of whole high-moisture shelled corn with ammonia. Can. 3. Anim. S c i . , 60: 683-688. - 142 -S t e e l , Y.L. and Saul, R.A. 1962. Laboratory measurements of the rate of d e t e r i o r i a t i o n of grain during drying. Am. Meeting Mid-Central Sec. Am. Soc. Agr. Eng. Lincoln, Nebraska, pp. 11. T a i t , R.M. 1979. The e f f e c t s of acid-preserved high-moisture barley and p e l l e t i n g on the u t i l i z a t i o n of a l l concentrate d i e t s by early-weaned lambs. Can. 3. Anim. S c i . , 59: 101-105. Thomson, F. and Lamming, G.E. 1972. The flow of digesta, dry matter and starch to the duodenum in sheep given rations containing straw of varying p a r t i c l e s i z e . Br. 3. Nutr., 28: 391-403. Tonroy, B.R. and Perry, T.W. 1974. E f f e c t of corn preservation treatments on in v i t r o d i g e s t i b i l i t y , ruminal pH and v o l a t i l e f a t t y acid formation. 3. Anim. S c i . , 38: 676-680. Tranchino, L. 1980. Economic aspects of nitrogen storage of grains. In; Controlled atmosphere storage of grains. Ed. Shejbal 3. E l s e v i e r Publishing Co., pp. 487-506. T r i s v y a t s k i i , L.A. 1969. Storage of grain (Russian t r a n s l a t i o n ) . Ed. Kent, N.C. and Freeman, 3. A. National Landing Library for Science and Technology, England. Vol 1 - 3 . Twumasi, 3. K. 1970. Propionic acid as a fungicide for the preservation of feed grain. M.Sc. Thesis, McGill University, Montreal, Que. As c i t e d by Oones et a l . (1974). Vaganova, V.A. 1976. Preservation of milk feeds with formaldehyde. N u t r i . Abstr. Rev. Ser. B. 1977; 47: 674. Van Cauwenberge, Y.E., Bothast, R.3. and Young, D.C. 1981. Comparison of controlled-released ammonia solutions and aqueous ammonia for preserving high-moisture maize. Cereal Chem., 58: 293-295. Waldern, D.E. 1971. A rapid micro-digestion procedure for neutral and acid detergent f i b e r . Can. 3. Anim. S c i . , 51: 67-69. Wallace, H.A.H. 1973. Fungi and other organisms associated with stored gr a i n . In: Grain Storage: Part of a system. Ed. Sinha, R.N. and Muir, W.E. Avi Publishing, Connecticut, pp. 71-98. Ware, D.R., S e l f , H.L. and Hoffmann, M.P. 1977. Comparison of chemically preserved and a r t i f i c i a l l y dried corn for f i n i s h i n g y e a r l i n g steers. 3. Anim. S c i . 44: 722-728. Watson, S.Y. and Nash, M.Y. 1960. The conservation of grass and forage crops. Oliver and Boyd Ltd., Edinburgh, pp. 96. Westermarck-Rosendahl, C. and Ylimaki, A. 1978. Spontaneous heating in newly harvested wheat and rye. 1. Thermogenesis and i t s e f f e c t on grain q u a l i t y . N u t r i . Abs. and Rev. Series B. 48:12. - 143 -Wheeler, W.E. and Noller, C H . 1977. G a s t r o i n t e s t i n a l t r a c t pH and starch in feces of ruminants. 3. Anim. S c i . 44: 131. Whiting, F., William Y.P. and L o o s l i , 3.K. 1949. Tocopheral (vitamin E) deficiency among sheep fed natural feeds. 3. Anim. S c i . , 8: 234-242. Wiley, W.R. and Stokes, Y.L. 1962. Requirement on an al k a l i n e pH and ammonia for substrate oxidation by B a c i l l u s p a s t e u r i i . 3. Bact., 84: 731-734. Woodward, 3.C. and Short, D.D. 1973. To x i c i t y of a l k a l i - t r e a t e d soyprotein in r a t s . 3. Nutr., 103: 569-574. Wyss, 0., Ludwig, B.3. and 3oiner, R.R. 1945. The f u n g i s t a t i c and fu n g i c i d a l action of fa t t y acids and related compounds. Arch. Biochem., 7: 415-425. Young, L.G., Brown, R.G. and Sharp, B.A. 1970. Propionic acid preservation of corn for pigs. Can. 3 Anim. S c i . , 50: 711-715. Zafren, S. Ya. and Makarova, K.G. 1976. N u t r i . Abst. Rev., Ser. B. 1977, 47:674. (Ru). 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            data-media="{[{embed.selectedMedia}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
https://iiif.library.ubc.ca/presentation/dsp.831.1-0095427/manifest

Comment

Related Items