Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The effect of various levels of roughages and various grains on the growth patterns of growing and fattening… Gardner, Joseph William 1973

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_1973_A6_7 G37_3.pdf [ 3.92MB ]
Metadata
JSON: 831-1.0101297.json
JSON-LD: 831-1.0101297-ld.json
RDF/XML (Pretty): 831-1.0101297-rdf.xml
RDF/JSON: 831-1.0101297-rdf.json
Turtle: 831-1.0101297-turtle.txt
N-Triples: 831-1.0101297-rdf-ntriples.txt
Original Record: 831-1.0101297-source.json
Full Text
831-1.0101297-fulltext.txt
Citation
831-1.0101297.ris

Full Text

c: THE EFFECT OF VARIOUS LEVELS OF ROUGHAGES AND VARIOUS GRAINS ON THE GROWTH PATTERNS OF GROWING AND FATTENING STEERS by JOSEPH WILLIAM GARDNER B.Sc.(Agr.), The U n i v e r s i t y of B r i t i s h Columbia, 1970 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN AGRICULTURAL SCIENCES i n the Department of Animal Science We accept t h i s t h e s i s as conforming t o the r e q u i r e d s t andard. THE UNIVERSITY OF BRITISH COLUMBIA A p r i l , 1973 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study. I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . I t i s understood t h a t copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be allowed without my w r i t t e n p e r m i s s i o n . Department The U n i v e r s i t y of B r i t i s h Columbia, Vancouver £, Canada. ABSTRACT In Study I a l f a l f a - b e r m u d a grass hay or oat straw was f e d w i t h r o l l e d b a r l e y , p e l l e t e d beet pulp, soybean o i l meal and cracked wheat, i n v a r i o u s p r o p o r t i o n s , i n twenty protein-supplemented r a t i o n s t o immature Hereford s t e e r s . A c o n t r o l r a t i o n of 10% l o n g straw, 7&% r o l l e d b a r l e y and 12% soybean o i l meal was i n c l u d e d . The best r e s u l t s were obtained w i t h a roughage l e v e l of 10%. However, i t was shown t h a t i t was f e a s i b l e to feed roughage l e v e l s as h i g h as 1+0% without d e t r i m e n t a l e f f e c t s t o e i t h e r average d a i l y g a i n , f e e d e f f i c i e n c y , or c a r c a s s q u a l i t y . In Study I I v a r i o u s f e e d g r a i n s were f e d i n the r a t i o 90:10 (concentrate t o roughage). The Canadian f e e d g r a i n s of b a r l e y and wheat were compared with c o r n . V a r i o u s r a t i o s o f these f e e d g r a i n s were a l s o compared. E x c e l l e n t g a i n s and f e e d e f f i c i e n c i e s were ob t a i n e d on a l l r a t i o n s and i t was shown t h a t the c o s t of the g r a i n s a v a i l a b l e would be the l a r g e s t f a c t o r i n determining which to use. TABLE OF CONTENTS PAGE INTRODUCTION 1 STUDY I THE EFFECT OF VARIOUS LEVELS OF ROUGHAGES ON THE GROWTH PATTERNS OF GROWING AND FATTENING STEERS A. INTRODUCTION 6 B. LITERATURE REVIEW 8 C. MATERIALS AND METHODS 16 (a) Feeding T r i a l E x p e r imental Design .... 16 Experimental Animals ... 16 Hous i n g 16 I n i t i a l Treatment and Feeding Procedure .... 17 Rations IS Weighing Procedure .... 22 R a t i o n Costs 22 (b) Management Procedures Adaption 24 Ringworm C o n t r o l 24 B l o a t i n Animals 24 R a t i o n Adjustments .... 2$ (c) Carcass T r i a l 26 (d) D i g e s t i b i l i t y T r i a l ... 27 D. RESULTS AND DISCUSSION (a) Feeding T r i a l Average D a i l y Gains ... 29 Feed Consumption 29 R a t i o n Cost per Kilogram of Gain 29 PAGE (a) Feeding T r i a l - continued Growth Curves 30 R a t i o n Analyses 30 F e e d l o t A p p l i c a t i o n 30 (b) Carcass T r i a l 34 (c) D i g e s t i b i l i t y T r i a l 36 STUDY I I THE EFFECT OF VARIOUS FEED GRAINS ON THE GROWTH PATTERNS OF GROWING AND FATTENING STEERS A. INTRODUCTION 39 B. LITERATURE REVIEW 41 C. MATERIALS AND METHODS (a) Feeding T r i a l E x p e r imental Design 4# E x p e r i m e n t a l Animals 4$ Housing 4$ I n i t i a l Treatment and Feeding Procedure 49 Rations 51 Weighing Procedure 51 R a t i o n Costs 51 (b) Management Procedures Adaption 55 Animal H e a l t h 55 R a t i o n P r e p a r a t i o n 56 (c) Carcass T r i a l 56 D. RESULTS AND DISCUSSION (a) Feeding T r i a l Average D a i l y Gains 57 V PAGE .'(a) Feeding T r i a l - continued Feed Consumption 57 Ration Cost per Kilogram of Gain 5o" Growth Data Ration Analyses 5$ Energy 63 (b) Carcass T r i a l 69 SUMMARY AND CONCLUSIONS STUDY I 72 STUDY I I 73 GENERAL CONCLUSIONS 75 BIBLIOGRAPHY 79 LIST OF TABLES PAGE STUDY I TABLE I. CONSTITUENTS OF RATIONS INCORPORATING STRAW 19 I I . CONSTITUENTS OF RATIONS INCORPORATING HAY 20 I I I . COMPOSITION OF EXPERIMENTAL PREMIX 21 IV. COSTS OF MATERIALS 23 V. AVERAGE DAILY GAINS AND FEED EFFICIENCIES 32 VI. PROXIMATE ANALYSES OF RATIONS 33 VII. PEN AVERAGE DRESSING PERCENTAGES, RIB EYE AND FAT COVER MEASUREMENTS 35 VIII. AVERAGE DRY MATTER DIGESTIBILITIES 37 STUDY II IX. RATION COMPOSITIONS AND COSTS 50 X. PROXIMATE ANALYSES OF FEEDSTUFFS 52 XI. COMPOSITION OF EXPERIMENTAL PREMIX 53 XII. COSTS OF MATERIALS 54 XIII. AVERAGE DAILY GAINS AND FEED EFFICIENCIES 59 XIV. AVERAGE DAILY GAINS IN PERIODS OF TWO WEEKS 60 v i i PAGE TABLE XV. FEED EFFICIENCY - KILOGRAMS OF FEED/KILOGRAMS OF GAIN 61 XVI. PROXIMATE ANALYSES OF RATIONS 62 XVII. NET ENERGY REQUIREMENTS OF GROWING AND FINISHING BEEF CATTLE 64 XVIII. NET ENERGY AND DIGESTIBLE PROTEIN VALUES OF FEEDS USED IN RATIONS 65 XIX. THEORETICAL FEED CONSUMPTION 66 XX. THEORETICAL VERSUS ACTUAL GAINS 67 XXI. PROTEIN REQUIREMENTS FOR FINISHING STEERS 70 XXII. RATION AVERAGE DRESSING PERCENTAGES 71 LIST OF FIGURES PAGE FIGURE STUDY I I. Growth Curve R a t i o n 1 31 STUDY I I I I . Energy R e l a t i o n s h i p s 42 ACKNOWLEDGMENTS The w r i t e r wishes t o express h i s g r a t i t u d e t o Dr. W.D. K i t t s , Chairman of the Departments of Animal Science and P o u l t r y S c i e n c e , f o r the encouragement, c o n s u l t a t i o n , and guidance r e c e i v e d throughout the course o f t h i s study, and f o r a l l o w i n g the use o f the departmental f a c i l i t i e s . The w r i t e r thanks Mr. D. Owen, L i v e s t o c k D i v i s i o n , Canada Department o f A g r i c u l t u r e , and Mr. R. H i l l , Richmond Packers, f o r t h e i r c o - o p e r a t i o n i n the ca r c a s s study and e v a l u a t i o n s e c t i o n of t h i s t h e s i s . Thanks are a l s o extended t o Mr. J.C. MacGregor and t o Mr. Wes Copeland o f the Department o f Animal Science f o r t h e i r a s s i s t a n c e d u r i n g the experimental work. INTRODUCTION Ruminants are unique i n th a t they f o s t e r i n t h e i r complex stomach a m i c r o b i a l p o p u l a t i o n . T h i s a s s o c i a t i o n i s r e q u i r e d f o r the ani m a l s ' w e l l - b e i n g . P h y s i o l o g i c a l l y and a n a t o m i c a l l y , the ruminant i s adapted t o u t i l i z e roughage. When i t i s r e a l i z e d t h a t over 60$ of the world's a g r i c u l t u r a l l a n d i s non-arable and o n l y s u i t e d f o r the p r o d u c t i o n o f roughage feeds o r f o r g r a z i n g , then c a t t l e , sheep, and c e r t a i n w i l d animals, are the only p r a c t i c a l means, a t l e a s t at present, o f u t i l i z i n g t h i s v a s t f e e d resource f o r the p r o d u c t i o n o f food f o r man. Most c a t t l e feeds are made up l a r g e l y o f roughages and c o n c e n t r a t e s . The main d i f f e r e n c e between roughages and con c e n t r a t e s i s i n the amount of f i b r e they c o n t a i n . Concentrates are low i n f i b r e with few of the common i n g r e d i e n t s of g r a i n (concentrate) r a t i o n s having over 10$ f i b r e . The amount of f i b r e i n roughages v a r i e s , w i t h hay crops a v e r a g i n g 28$ crude f i b r e , and straws 3$%. The f i b r e component of the fe e d i s composed mainly o f c e l l u l o s e , h e m i e e l l u l o s e , and l i g n i n , and i s dependent on the s t a t e of m a t u r i t y o f the p l a n t . D i g e s t i o n o f t h e 2. f o r a g e g e n e r a l l y becomes l e s s e f f i c i e n t w i t h i n c r e a s i n g f i b r e content. T h i s f i b r e component of roughages i s l a r g e l y carbohydrate but, because o f i t s i n s o l u b l e n a t u r e , i t i s o n l y p a r t i a l l y u t i l i z e d as a food n u t r i e n t by ruminants. The unique d i g e s t i v e system of the ruminant has prompted much work on the u t i l i z a t i o n o f h i g h c e l l u l o s e feeds i n growing r a t i o n s . In r e c e n t years, t h e r e has been a t r e n d t o f e e d beef c a t t l e high-energy l o w - f i b r e r a t i o n s . Even though s t e e r s and h e i f e r s can be f i n i s h e d on d i e t s l a c k i n g roughage, t h i s procedure i s not without hazards and o f f e r s l i t t l e to the o v e r - a l l e f f i c i e n c y of beef c a t t l e p r o d u c t i o n . Research has i n d i c a t e d t h a t t h e r e i s a p r a c t i c a l minimal l e v e l f o r roughage f e d t o animals r e c e i v i n g "high energy d i e t s " . I t i s f e l t by many t h a t a p h y s i c a l roughness f a c t o r i n the r a t i o n i s r e q u i r e d f o r the rumen to m a i n t a i n i t s normal f u n c t i o n -i n g p a t t e r n . The Food and A g r i c u l t u r e O r g a n i z a t i o n of the U n i t e d Nations (FAO 1971) has made a l a r g e number of a g r i c u l t u r a l commodity p r o j e c t i o n s which emphasize the importance of r e s e a r c h i n beef p r o d u c t i o n . The pro-j e c t i o n s are f o r the time p e r i o d of 1970-19^0. They p r o j e c t t h a t i n 19#0 the annual wheat p r o d u c t i o n i n Canada w i l l be about the same as the annual p r o d u c t i o n 3. obtained i n the base per i o d of I964-I966; however, l e s s acreage w i l l be i n v o l v e d . I t i s i n t e r e s t i n g t o note t h a t the pr o j e c t e d production of both corn and b a r l e y , however, w i l l be b e t t e r than 200$ of the annual production i n the base per i o d of 1964-1966. The annual production of beef and v e a l i n North America i n 1964-1966 was 9.73 m i l l i o n t o n s , w i t h an average carcass weight of 481 pounds. In 1970 t h i s production increased to 11.24 m i l l i o n t o n s , w i t h an average carcass weight of 506 pounds. The p r o -j e c t e d annual production f o r beef and v e a l i n 1980 i n North America i s 14.09 m i l l i o n t o n s , w i t h an average carcass weight of 590 pounds. In the 1964-1966 base period i n North America, the annual average per c a p i t a consumption of beef and v e a l was 105 pounds. By 1970 t h i s had r i s e n to 115 pounds. The pr o j e c t e d increase by 1980 shows an annual per c a p i t a demand f o r beef and v e a l of 133 pounds. When t h i s i s coupled w i t h the l a r g e increase i n popula-t i o n expected and the r o l e North America may be able t o play i n he l p i n g those c o u n t r i e s of lower economic s t a t u s , the growth expected i n the beef i n d u s t r y alone can only be considered as phenomenal. The world l e v e l of t o t a l annual demand f o r beef and v e a l i s p r o j e c t e d to be approximately 200$ of the annual demand i n the 1964-1966 base p e r i o d , which was 32.£3 m i l l i o n m etric t o n s . T h i s Study i s d i v i d e d i n t o two s e c t i o n s . In Study I, d i f f e r e n t roughage sources and l e v e l s were f e d w i t h v a r i o u s g r a i n s i n a c a t t l e f e e d i n g t r i a l . I t has g e n e r a l l y been co n s i d e r e d t h a t high roughage f a t t e n i n g r a t i o n s have an u n d e s i r a b l e e f f e c t on c a r c a s s composition. An assessment o f the c a r c a s s c h a r a c t e r i s t i c s of those animals i n the f e e d i n g t r i a l was made. As roughage content o f a feed has a marked e f f e c t on the r a t i o n d i g e s t i b i l i t y t h i s Study i n c l u d e d d i g e s t i b i l i t y e v a l u a t i o n s of the experimental r a t i o n s . In Study I I , a f e e d i n g t r i a l was conducted where the roughage t o concentrate r a t i o of the d i e t remained the same with v a r i a t i o n s w i t h i n the concen-t r a t e p r o p o r t i o n . The primary aim of t h i s Study was to demonstrate t h e c a p a c i t y o f corn, b a r l e y , and wheat to e l i c i t comparable r e s u l t s , and to i n v e s t i g a t e the e f f e c t o f mixing the g r a i n s i n v a r i o u s p r o p o r t i o n s . 5. STUDY I THE EFFECT OF VARIOUS LEVELS OF ROUGHAGES ON THE GROWTH PATTERNS OF GROWING AND FATTENING STEERS 6. A. INTRODUCTION The most e f f i c i e n t u t i l i z a t i o n of f e e d i n f a t t e n i n g beef s t e e r s i s a s s o c i a t e d with h i g h r a t e s o f g a i n , which means hig h d a i l y f e e d i n t a k e s and h i g h percentages o f g r a i n i n the r a t i o n . The c h a r a c t e r -i s t i c s o f h i g h g r a i n r a t i o n s t h a t produce t h i s e f f i c i e n c y are a h i g h c o n c e n t r a t i o n of energy and low b u l k . F u r t h e r advantages of u s i n g these r a t i o n s are ease of mechanical h a n d l i n g w i t h a lower l a b o u r c o s t , and a g r e a t e r t u r n o v e r of animals i n the f e e d l o t , w i t h a r e s u l t a n t h i g h e r c a p i t a l t u r n o v e r than c o u l d be achieved w i t h high-roughage r a t i o n s . There are , however, disadvantages i n u s i n g h i g h g r a i n r a t i o n s . These i n c l u d e a p o s s i b l e occurrence of rumen p a r a k e r a t o s i s , l i v e r abscesses, founder and b l o a t . T h i s study i n v o l v e s a f e e d i n g t r i a l examining the i n c l u s i o n of l o w - q u a l i t y roughages i n i n t e n s i v e f a t t e n i n g r a t i o n s . T h i s a l s o i n c l u d e s an i n s p e c t i o n o f the e f f e c t s of the f e e d i n g t r i a l on c a r c a s s c h a r a c t e r i s t i c s . D i g e s t i b i l i t y s t u d i e s o f the e x p e r i -mental r a t i o n s were done i n o r d e r to assess more a c c u r a t e l y the use o f l o w - q u a l i t y roughages i n beef c a t t l e r a t i o n s . 7. In terms of o b t a i n i n g the most e f f i c i e n t use o f the beef animal, m o d i f i c a t i o n o f the roughage t o c e r e a l r a t i o shows great promise i n maximizing p r o d u c t i o n from g r a i n based d i e t s . Economy i n the u t i l i z a t i o n of c e r e a l energy and n i t r o g e n can o n l y be achieved under i n t e n s i v e s p e c i a l i z e d c o n d i t i o n s of p r o d u c t i o n , and the beef producer i s g r e a t l y i n need of q u a n t i t a t i v e i n f o r m a t i o n on d i e t a r y balance i n o r d e r to maximize output. 8. B . LITERATURE REVIEW The unique d i g e s t i v e system of c a t t l e has prompted much work on the i n c o r p o r a t i o n of high c e l l u l o s e feeds i n t o e f f i c i e n t growing r a t i o n s . Beeson and Perry (1952) s t a t e d t h a t "at present, a l a r g e p r o p o r t i o n of roughages (corn cobs, soybean straw, oat straw and grass s i l a g e ) i s being wasted through improper use. Each year, over 20 m i l l i o n tons of corn cobs are produced, but by f a r the l a r g e r share i s burned or thrown out t o r o t " . In f i v e experiments, using immature Hereford s t e e r s , Beeson and Perry (1952) were able t o o b t a i n gains of 1.2# to 1.56 pounds d a i l y by feeding ground corn cobs and p r o t e i n , and 2.06 t o 2.21 pounds d a i l y gain when corn s i l a g e and p r o t e i n supplement were f e d . The feeding of a l l - c o n c e n t r a t e d i e t s t o ruminants i s not a new concept. However, the e f f e c t s of feeding a l l - c o n c e n t r a t e d i e t s to immature growing animals are very i n t e r e s t i n g . Davenport (1897) was u n s u c c e s s f u l i n attempts t o r e a r calves on r a t i o n s devoid of roughage, and concluded t h a t f i b r o u s m a t e r i a l s were necessary i n the ruminant d i e t . This f a c t was confirmed by s e v e r a l experimenters. Huffman (1928) po s t u l a t e d an "unknown f a c t o r " i n hay necessary t o maintain the h e a l t h of c a t t l e . Geurin et a l (1959) 9. f e d c o ncentrate d i e t s supplemented with b a r l e y which was r o l l e d t o preserve the roughage c h a r a c t e r i s t i c s o f the h u l l s . These workers r e p o r t e d gains up t o 2.95 pounds per day on a 32% p r o t e i n supplement and r o l l e d b a r l e y . Bond (1966) conducted an experiment u s i n g an a l l - c o n c e n t r a t e corn r a t i o n versus a roughage r a t i o n . He r e p o r t e d f a s t e r g a i n s and lower f e e d c o n v e r s i o n r a t e s by the animals on the a l l -c o ncentrate r a t i o n . Although h i g h - c o n c e n t r a t e r a t i o n s r e s u l t i n b e t t e r gains and fe e d c o n v e r s i o n than do h i g h -roughage r a t i o n s and show a b e t t e r a d a p t i o n t o mixing, h a n d l i n g and storage, s e v e r a l important and c o s t l y s i d e e f f e c t s can occur. A r e p o r t by Haskins et a l (I969) summarized some of the e f f e c t s o f high-concen-t r a t e r a t i o n s as f o l l o w s : 1. A h i g h i n c i d e n c e o f rumen p a r a k e r a t o s i s and l i v e r abscesses i n animals f e d high-energy r a t i o n s o c c u r r e d . 2. I n c l u s i o n o f roughage (hay) d r a s t i c a l l y reduced (from 67% to 0%) the i n c i d e n c e o f abscessed l i v e r s , i n d i c a t i n g t h a t the p h y s i c a l p r o p e r t i e s of the roughage source are i n v o l v e d . 3. Rapid accumulation of v o l a t i l e f a t t y a c i d s , l a c t i c a c i d , and lo w e r i n g o f rumen pH, which may be a n t a g o n i s t i c t o the rumen e p i t h e l i u m , were observed. In a t r i a l conducted by C u l l i s o n (1961), the e f f e c t s o f g r i n d i n g and p e l l e t i n g a r a t i o n con-t a i n i n g 30% Bermuda gras s hay and 50% ground s h e l l e d corn w i t h p r o t e i n and m i n e r a l supplements, and the e f f e c t s o f i n c l u d i n g long oat straw on f a t t e n i n g c a l v e s , were s t u d i e d at s l a u g h t e r , f o l l o w i n g f e e d i n g p e r i o d s o f 196 and 210 days r e s p e c t i v e l y . V a r y i n g degrees of an abnormal rumen w a l l were observed i n animals on both ground and p e l l e t e d r a t i o n s . The p a p i l l a e o f the rumen of these c a l v e s appeared dark and e x c e s s i v e l y l o n g . K e r a t i n o u s t i s s u e was s l o u g h i n g o f f some areas of the rumen w a l l . Those animals on a c o n t r o l r a t i o n o f co n c e n t r a t e s and long hay e x h i b i t e d a normal rumen w a l l , while those which r e c e i v e d straw w i t h the b a s i c r a t i o n , e x h i b i t e d a y e l l o w i s h but o t h e r -wise normal rumen. From s t u d y i n g experiments i n v o l v i n g the use of roughage s u b s t i t u t e s , i t seems t h a t the i n c l u s i o n of roughage per se i n the form of hay or straw i s d e s i r a b l e . The great m a j o r i t y o f f e e d l o t o p e r a t o r s are p a i d on the b a s i s of a v i s u a l e v a l u a t i o n o f the l i v e animals r a t h e r than an e v a l u a t i o n of the c a r c a s s produced. They are not p e n a l i z e d f o r bad l i v e r s on e i t h e r system. They may f e e l , t h e r e f o r e , t h a t i n c r e a s e d f e e d e f f i c i e n c y , r a t e o f g a i n and ease o f feed h a n d l i n g , o f f s e t the r i s k o f d i g e s t i v e upsets common wit h h i g h - g r a i n r a t i o n s . A l l - g r a i n r a t i o n s have been f e d succes s -f u l l y . However, they appear t o be most s u c c e s s f u l w i t h h i g h - f i b r e g r a i n s such as oats or b a r l e y , r o l l e d so as t o r e t a i n a f i b r o u s c o n s i s t e n c y . Hironaka et a l (1962) conducted an experiment t o determine the e f f e c t s of l e v e l of f e e d consumption of an a l l - b a r l e y r a t i o n on r a t e and e f f i c i e n c y of g a i n by s t e e r s . The b a r l e y was f e d dry, crimped with a m i n e r a l - v i t a m i n supplement at l e v e l s c a l c u l a t e d t o produce a g a i n o f 1.0, 1.5, 2.0, and 2.5 pounds per day. The corresponding f e e d conversions ( l b s . f e e d / l b s . g a i n ) , were 10.92, 8.51, 7.02, and 7.05. Randomly f i v e o f the s t e e r s became c h r o n i c b l o a t e r s , and one s t e e r had s m a l l l i v e r a bscesses. Assuming t h a t a c e r t a i n amount of roughage i s necessary i n the r a t i o n s o f f e e d l o t c a t t l e , the exact p r o p o r t i o n s o f concentrate t o roughage must be known i f maximum performance i s t o be obtained from them. A g e n e r a l recommendation i s t h a t a minimum of 10$ roughage be i n c l u d e d i n a r a t i o n t o prevent d i g e s t i v e u p s e t s . I f the roughage percentage i s i n c r e a s e d , lower rates of gain and decreasing feed efficiency-w i l l occur. Experiments using various l e v e l s of roughage i n the ra t i o n have been c a r r i e d out. Richardson et a l (1961), using roughage to concentrate ra t i o s of 1:1, 1:3, and 1:5 of a l f a l f a hay and cracked sorghum grain, found the highest average gain was with the 1:5 r a t i o . White and Reynolds (1969), using 20$ and 40$ a l f a l f a hay as the roughage source, with ground sorghum grain and soybean meal as the concentrate sources, showed that consumption of a ration containing 40$ hay was higher than that of a ration containing 20$ roughage, and higher than the consumption of the a l l -concentrate r a t i o n . They showed that the source of roughage influenced the gain and carcass weights. Swan and Lamming (I969) cited research at the University of I l l i n o i s where t r i a l s were conducted using concen-trate-roughage r a t i o s varying from 80:20 to 0:100 on a l l - p e l l e t e d rations containing ground shelled corn and soybean o i l meal with ground hay as the roughage source. Highest average d a i l y gains were obtained with a 60:40 concentrate to roughage r a t i o n . Best feed conversion was with the 80$ concentrate rat i o n , but average d a i l y gain did not increase by r a i s i n g the concentrate l e v e l from 60% t o 80%. Feed i n t a k e was reduced at the 80% c o n c e n t r a t e l e v e l , with the best d r e s s i n g percentages at the h i g h l e v e l s of c o n c e n t r a t e s . Performance and f e e d c o n v e r s i o n e f f i c i e n c i e s have been shown t o improve wi t h h i g h e r concentrate r a t i o n s . The h i g h e r l e v e l s of c o n c e n t r a t e s have improved d r e s s i n g percentages, c a r c a s s grades, and brought about a r e d u c t i o n i n the f i n i s h i n g times r e q u i r e d f o r marketing. S e v e r a l c o s t l y s i d e e f f e c t s become more frequent with h i g h e r g r a i n l e v e l s and, consequently, b e t t e r management p r a c t i c e s are n e c e s s a r y . L o c a l c o n d i t i o n s and a v a i l a b i l i t y w i l l determine which feeds are most economical; the c o s t o f d i f f e r e n t f e eds, i n r e l a t i o n t o t h e i r n u t r i t i v e v a l u e , being an important c o n s i d e r a t i o n . When d e c i d i n g upon the most economical r a t i o n t o f e e d , r a t e and e f f i c i e n c y of l i v e weight g a i n , as w e l l as d r e s s i n g percentage and c a r c a s s grade expected, must a l s o be c o n s i d e r e d . D i g e s t i o n t r i a l s with animals f e d t o t a l mixed r a t i o n s has, i n the p a s t , g e n e r a l l y i n v o l v e d confinement to d i g e s t i o n c r a t e s or the use of f e c a l c o l l e c t i o n apparatus. E l l e n b e r g e r et a l ( 1 9 2 7 ) , N o b l i t t et a l ( 1 9 6 3 ) , and Waldo et a l ( 1 9 6 1 ) , have r e p o r t e d t h a t s t r e s s s i g n i f i c a n t l y a f f e c t s the d i g e s t i b i l i t y o f n u t r i e n t s . Much of the work which has been conducted w i t h the use of chromic oxide as an e x t e r n a l i n d i c a t o r o f d i g e s t i b i l i t y has been devoted t o techniques which w i l l r e s u l t i n samples t h a t are r e p r e s e n t a t i v e of the t o t a l f e c a l e x c r e t i o n . Crampton and L l o y d (1951) r e p o r t e d s a t i s f a c t o r y co-e f f i c i e n t s o f d i g e s t i b i l i t y w i t h sheep when random samples were taken d a i l y f o r f o u r days and composited f o r each animal. B r a d l e y (1958) found c l o s e agreement between d i g e s t i o n c o e f f i c i e n t s . f o r crude p r o t e i n and gross energy c a l c u l a t e d from: t o t a l c o l l e c t i o n of f e c e s , t wice d a i l y samples, and 7-day composited samples f o r s t e e r s i n metabolism c r a t e s . D i g e s t i o n c o e f f i c i e n t of a n u t r i e n t i s d e s c r i b e d a s : D i g e s t i o n c o e f f i c i e n t = 100 ( § ^ ) 3. p a r t s o f n u t r i e n t / u n i t of index substance i n food. p a r t s of n u t r i e n t / u n i t o f index substance i n f e c e s . Many experiments quoted by Schurch et a l (1950) i n d i c a t e t h a t the Cr203 method can r e p l a c e the c o n v e n t i o n a l procedures f o r determining d i g e s t i b i l i t y where a = b = o f r a t i o n s o r n u t r i e n t s consumed. As a main advantage, the method lead s t o a s i m p l i f i e d e x p e r i -mental procedure by a v o i d i n g the n e c e s s i t y o f a q u a n t i t a t i v e r e c o r d of e i t h e r food i n t a k e o r f e c e s output. The chemical work, however, i s i n c r e a s e d by the n e c e s s i t y t o determine the C^O^ content of f e e d and f e c e s . An easy, r a p i d and a c c e p t a b l y -a c c u r a t e a n a l y t i c a l method of C ^ C ^ i s , t h e r e f o r e , o f primary importance. Recent work, designed t o study the e f f e c t of f e c a l c o l l e c t i o n apparatus on the d i g e s t i b i l i t y o f n u t r i e n t s by s t e e r s f e d a complete p e l l e t e d r a t i o n ad l i b i t u m , and t o compare t o t a l c o l l e c t i o n v e rsus chromic oxide i n d i c a t o r d i g e s t i b i l i t y co-e f f i c i e n t s , was completed by Phar et a l (1971)• T h e i r r e s u l t s , g e n e r a l l y i n d i c a t e d no s i g n i f i c a n t d i f f e r e n c e between methods employed. MATERIALS AND METHODS (a) Feeding T r i a l E x p e r imental Design The experimental animals were randomly-a l l o c a t e d t o twenty pens w i t h each pen randomly r e c e i v i n g one of twenty e x p e r i -mental r a t i o n s . The animals were s l a u g h t e r e d when they reached a l i v e weight of 454-477 k i l o g r a m s . One animal from each r a t i o n group was r e t a i n e d at the c o n c l u s i o n of the f e e d i n g t r i a l t o f a c i l i t a t e a d i g e s t i b i l i t y t r i a l . E x p erimental Animals The experimental animals (100 Hereford s t e e r c a l v e s ) were obtained from the Douglas Lake C a t t l e Co., Douglas Lake, B.C., and were s e l e c t e d on the b a s i s o f u n i f o r m body weights and conformation. The average weight of the animals when r e c e i v e d at the f e e d l o t was 200 k i l o g r a m s . The s t e e r s were a l l e a r -tagged and a l l o c a t e d at random t o pens, f i v e animals i n each. Housing Each group was c o n f i n e d i n a 3*65 meter by 9.14 meter pen, a l l o w i n g each animal 6.67 square meters of a r e a . Each pen was bedded 17. with wood shavings, and shavings were added as needed. Water and cobalt-iodized s a l t blocks were provided ad lib i t u m to a l l groups. I n i t i a l Treatment and Feeding Procedure On a r r i v a l at the experimental f a c i l -i t i e s , the animals were fed alfalfa-bermuda grass hay (long form). The animals were given injections of Provite^ (1 cc.) (Vitamins A, D2, and E), to prevent or correct any vitamin d e f i c i e n c i e s , and Rea-P l e x 2 (2 cc.) f o r prevention of infectious bovine r h i n o t r a c h e i t i s . The hay diets were supplied f o r 17 days, and grain was added on day 17, at 1.9 kg/animal/day. The experimental vitamin-mineral Premix-^ was added at .45 kg/animal/day on day 24, and the hay constituent was added i n the chopped form on day 25. The animals were given a f u l l 5-week t r a n s i t i o n period and were on Ayerst Laboratories D i v i s i o n of Ayerst, McKenna & Harrison Limited, Montreal, Quebec. Fort Dodge Laboratories Inc., Fort Dodge, Iowa. Vitamin-Mineral Premix Composition Table I I I . f u l l experimental r a t i o n s by day 35. A l l s t e e r s were subcutaneously implanted i n the ear with 36 mg of D i e t h y l s t i l b e s t r o l (DES) to o b t a i n i n c r e a s e d f e e d e f f i c i e n c i e s and r a t e o f g a i n t h a t had been ob t a i n e d i n the l i t e r a t u r e . The d a i l y f e e d i n g procedure d u r i n g t h e experiment i n v o l v e d f e e d i n g once per day, each morning. On weighing days, f e e d was wi t h h e l d one hour u n t i l weighing was com-p l e t e d . The animals were f e d as much as they could consume i n 24 hours ( f u l l f e e d ) . Rations Rations were designed t o not be l i m i t -i n g n u t r i t i o n a l l y and to be i s o n i t r o g e n o u s . R a t i o n compositions are giv e n i n Tables I and I I . P r o t e i n and V i t a m i n - M i n e r a l Premix composition are g i v e n i n Table I I I . Methods of a n a l y s i s used are those p u b l i s h e d by the A s s o c i a t i o n of O f f i c i a l A g r i c u l t u r a l Chemists (I960). TABLE I CONSTITUENTS OF RATIONS INCORPORATING STRAW ( a i r dry b a s i s ) (Day 1 - Day 150) Ration Straw % B a r l e y % Wheat % Beet Pulp % Soybean o i l meal % 1 h 10 78 12 2 C 10 78 12 3 C 25 60 15 4 C 40 42 18 5 C 10 61.6 15.4 13 6 C 25 47.2 11.a 16 7 C 40 33.2 8 18.5 8 C 10 82.5 7.5 9 C 25 63.5 11.5 10 C 40 44 16 (Day 150 - Slaughter) 1 C 10 78 12 2 c 10 78 12 3 c 10 78 12 4 c 10 78 12 5 c 10 61.6 15.4 13 6 c 10 61.6 15.4 13 7 c 10 61.6 15.4 13 8 c 10 82.5 7.5 9 c 10 82.5 7.5 10 c 10 82.5 7.5 L e t t e r (L) or (C) before Straw Percent denotes long or chopped. N.B. In a d d i t i o n to the i n d i c a t e d r a t i o n each animal received .45 kg per day of the experimental Vitamin-Mineral supplement. TABLE I I CONSTITUENTS OF RATIONS INCORPORATING HAY ( a i r dry b a s i s ) (Day 1 - 9 5 ) R a t i o n Hay B a r l e y % Wheat $ Beet Pulp % Soybean o i l meal % 11 h 10 81 9 12 C 10 81 9 13 C 25 69 6 14 c 40 56.5 3.5 15 c 10 64 16 10 16 c 25 51.4 13.6 7.0 17 c 40 44.8 11.2 4.0 18 c 10 86 4 19 c 25 73.5 1.5 20 c 40 60 (Day 95 - 150) 11 L 10 90 12 C 10 90 13 C 25 75 14 C 40 60 15 C 10 74 16 16 C 25 61.4 13.6 17 C 40 48.8 11.2 18 C 10 90 19 C 25 75 20 C 40 60 (Day 150 - S l a u g h t e r ) 11 C 10 90 12 C 10 90 13 C 10 90 14 C 10 90 15 C 10 74 16 16 C 10 74 16 17 C 10 74 16 18 C 10 90 19 C 10 90 20 c 10 90 ^ L e t t e r (L) or (C) before Hay Percent denotes l o n g o r chopped. N.B. In a d d i t i o n t o the i n d i c a t e d r a t i o n each animal r e c e i v e d .45 kg per day of the experimental V i t a m i n - M i n e r a l supplement. TABLE I I I COMPOSITION OF EXPERIMENTAL PREMIX Vitamin-•Mineral Supplement Vitamin A - 140 gm (325, 000 I.U. per gm) Vitamin D - 120 gm (80 m i l l i o n I.U. per l b . ) C u S 0 4 40 gm CoSO^ 40 gm MnSO^ - 600 gm ZnS04 - 1000 gm Prodine - 36 (170 mg Iodine per gm) Experimental Premix  (fed at .45 kg per head per day) Vitamin Mix as above 4 . 5 kg Limestone 6 3 . 6 kg D i c a l c i u m Phosphate 4 5 . 4 kg S a l t 7 2 . 7 kg Barley 6 1 8 . 1 kg Shorts 9 0 . 8 kg Tallow 1 3 . 6 kg T o t a l 909 kg 22. Weighing Procedure Weighing of a l l experimental c a t t l e was done bi-weekly. A f t e r being weighed a few times, the animals became accustomed to the procedure and the o p e r a t i o n was done with a minimum of d i s t u r b a n c e . R a t i o n Costs Costs of a l l r a t i o n c o n s t i t u e n t s and o t h e r m i s c e l l a n e o u s c o s t s are g i v e n i n Table IV. Soybean o i l meal was the most expensive c o n s t i t u e n t at $ 1 3 1 . 0 0 per t o n . R a t i o n c o s t s were reasonably low c o n s i d e r i n g t h a t the f e e d l o t was a c o n s i d e r a b l e d i s t a n c e from the areas of f e e d p r o d u c t i o n . TABLE IV COSTS OF MATERIALS Hay $51.80/ton (metric) ($47.00/ton (Short)) St raw $33.58 » rt ($35.00 " " ) Barl e y $57.32 . " tt ($53.00 » » ) Wheat $69.44 " it ($63.00 " " ) Beet Pulp $71.65 » tt ($65.00 " n ) Experimental Premix $33.18 » tt ($30.00 » " ) Soybean o i l meal $144.40 " tt ($131.00 " " ) Other Costs Ear Tags - Re~usable Scale - $30.00 (maintenance) S a l t Blocks - $22.50 D i e t h y l s t i l b e s t r o l implants - $35.00 (3.5 cents/animal) C a t t l e 100 head -49,310 @ 33.50 cwt l e s s 4% s h r i n k $19,176.35 767.04 13,409.31 plus f r e i g h t @ .75/cwt. 353.64 $18,768.45 (b) Management Procedures  Adaption The animals adapted exceedingly w e l l t o the r a t i o n s and the experimental environment. A l l were shipped d i r e c t l y from range c o n d i -t i o n s and, immediately upon a r r i v a l a t the experimental f a c i l i t i e s , were s t a r t e d on s o l i d f o o d . No s h i p p i n g f e v e r was evident and a l l q u i c k l y adapted to the f e e d l o t environment. Ringworm C o n t r o l An outbreak of ringworm (Trichophyton  verrucosum) o c c u r r e d d u r i n g the experiment, a f f l i c t i n g , i n v a r y i n g degrees, over 70$ o f the animals. The outbreak was c o n t r o l l e d with t o p i c a l a p p l i c a t i o n s o f C a p i t a n ^ and motor o i l to i n f e c t e d a r e a s . The i n f e c t i o n subsided f o l l o w i n g repeated a p p l i c a t i o n s . B l o a t i n Animals One animal i n Group 17 (#20), on a r a t i o n c o n t a i n i n g 40$ straw, began b l o a t i n g on day 65. Treatment by drenching w i t h 6 ounces o f T u r c a p s o l ^ and hosing was s u c c e s s f u l . The Canadian I n d u s t r i e s L t d . , Vancouver, B r i t i s h Columbia. Pitman Moore, Don M i l l s , O n t a r i o . animal again b l o a t e d on day 80 and was t r e a t e d a g a i n . B l o a t i n g repeated a g a i n on day 9 0 , and treatment had no e f f e c t a f t e r t h a t date. Consequently the animal was sl a u g h t e r e d on day 9 6 , and dressed at 1 5 4 . 5 kg with a d r e s s i n g percentage o f 57%. R a t i o n Adjustments The r a t i o n adjustments were made f o r two b a s i c reasons: 1. Grass hay was no l o n g e r a v a i l a b l e and s w i t c h i n g t o a l f a l f a hay caused an i n c r e a s e i n the p r o t e i n content o f r a t i o n s 1 1 - 2 0 . 2 . Animals had reached 286-348 kg l i v e weight at t h i s time, and r a t i o n s would have had p r o t e i n l e v e l s of 13 .97% to 1 6 . 9 % . The N a t i o n a l Research C o u n c i l recommendation i s 10 .4% t o t a l p r o t e i n . On day 95 of the experiment, soybean o i l meal was e l i m i n a t e d from the hay r a t i o n s . A l l o ther r a t i o n concentrate c o n s t i t u e n t s were r a i s e d to g i v e 100% t o t a l s . 26. (c) Carcass T r i a l The animals were s l a u g h t e r e d when they reached a l i v e weight of 454-477 k i l o g r a m s . The f o l l o w i n g data were c o l l e c t e d : 1. S h i p p i n g weight 2. Hot c a r c a s s weight 3. Government grade 4. Rib eye measurement 5. Fat cover measurement The s h i p p i n g weight of each animal was ob t a i n e d p r i o r t o i t l e a v i n g the experimental f a c i l i t i e s , a f t e r the animals * f e e d had been w i t h h e l d f o r 12 hours. Both the hot ca r c a s s weight and the government grade are a matter of procedure. The only arrangement t h a t had to be made was f o r the ear t a g t o remain with the c a r c a s s . T h i s was done by c u t t i n g the ear t a g out o f the e a r at s l a u g h t e r and p i n n i n g i t i n the body c a v i t y of the gu t t e d c a r c a s s . Approximately one week l a t e r , w h i le the c a r c a s s e s were s t i l l i n the c o o l e r , the r i b eye and f a t cover measurements were taken. T h i s was done by t a k i n g the r i g h t s i d e and d i v i d i n g the q u a r t e r s between the 11th and 12th r i b s . A t r a n s p a r e n t p l a s t i c g r i d with 2.54 cm spacings was then p l a c e d over the l o i n eye (longissmus d o r s i ) and a measurement taken. The f a t cover measurements were taken by o b t a i n i n g the l e n g t h o f the l o i n eye from the back bone down the s i d e and then t a k i n g f a t measurements at one-quarter, one-half, and t h r e e - q u a r t e r s o f t h i s d i s t a n c e . D i g e s t i b i l i t y T r i a l One animal from each r a t i o n group was re-t a i n e d at the c o n c l u s i o n o f the f e e d i n g study to f a c i l i t a t e a d i g e s t i b i l i t y t r i a l . These animals were f e d 6.8 kilograms o f t h e i r r e s p e c t i v e r a t i o n s and 32 grams of chromic oxide i n c a p s u l a t e d form. F e c a l samples were c o l l e c t e d each day and chromic oxide d e t e r -minations were made. A b a l l i n g gun was used to a d m i n i s t e r the capsules to the animals. U n f o r t u n a t e l y two s t e e r s had to be shipped as they would not adapt t o the procedure used. Because of the reduced number of animals, the d i g e s t i o n t r i a l was repeated, with the same animals being used t o t e s t d i f f e r e n t r a t i o n s . The s t e e r s r e c e i v e d the Cr^O-j f o r 17 consecu-t i v e days, w i t h f e c a l c o l l e c t i o n s b e i n g taken f o r the l a s t 7 days. The animals were g i v e n the marker each day a t 9 a.m., and the f e c a l c o l l e c t i o n s were done at 4 p.m. The procedure used i n the chromic oxide d e t e r m i n a t i o n was as f o l l o w s : 1 to 2 gm of feed or f e c e s were ashed i n a 75 ml n i c k e l c r u c i b l e at about 6 0 0°C. A f t e r c o o l i n g , approximately 1 gm of Na202 was added, mixed w e l l w i t h the ash by s w i r l i n g the c r u c i b l e , and the mixture f u s e d at g e n t l e heat u n t i l l i q u i d . The h e a t i n g was continued f o r about f i v e minutes a t a low red heat, s w i r l i n g the c r u c i b l e o c c a s i o n -a l l y . When c o l d , the c r u c i b l e was p l a c e d i n a 500 ml beaker and c o l d d i s t i l l e d water was added to d i s s o l v e the r e s i d u e . The s o l u t i o n was l e f t s t a n d i n g f o r f i v e t o t e n minutes, then t r a n s -f e r r e d i n t o a beaker. The c r u c i b l e was washed thoroughly w i t h hot d i s t i l l e d water. The s o l u -t i o n was l e f t s t a n d i n g i n the beaker f o r about t h i r t y minutes, then f i l t e r e d i n t o an Erlenmeyer f l a s k and the r e s i d u e was washed with warm d i s -t i l l e d water. The f i l t r a t e was t r a n s f e r r e d i n t o a 500 ml v o l u m e t r i c f l a s k and made up t o volume w i t h d i s t i l l e d water. L i g h t t r a n s m i s s i o n was measured with a p h o t o e l e c t r i c c o l o r i m e t e r , u s i n g a 440 mu f i l t e r , and w i t h d i s t i l l e d water as a blank. The amount of O 2 O 3 was determined from a standard c a l i b r a t i o n curve. (Schurch et a l . 1950) RESULTS AND DISCUSSION (a) Feeding T r i a l Average D a i l y Gains Average d a i l y gains were c a l c u l a t e d on a b a s i s of 14-day i n t e r v a l s . T h i s method i s l e s s a r b i t r a r y than c a l c u l a t i n g on a d a i l y b a s i s . Table V i n d i c a t e s t h a t the l a r g e s t average d a i l y gains were obtained w i t h R a t i o n No. 12 {10% chopped hay, 81% s t e a m - r o l l e d b a r l e y and 9% soybean o i l meal). Feed c o s t s and f e e d e f f i c i e n c i e s must be c o n s i d e r e d i n or d e r t o e s t a b l i s h the most p r a c t i c a l r a t i o n . Feed Consumption Rati o n No. 12 had the lowest f e e d con-sumption i n the 227-272 kg range and R a t i o n No. 13 had the lowest f e e d consumption i n the 2 7 2 - 3 1 8 kg range. R a t i o n Cost per Kilogram o f Gain The cost o f each r a t i o n , and the kilograms of f e e d r e q u i r e d f o r one k i l o g r a m of g a i n , are the two main p o i n t s t o c o n s i d e r i n c a l c u l a t i n g the c o s t per k i l o g r a m o f g a i n . As the e x p e r i -ment progressed, the c o s t o f one k i l o g r a m o f g a i n i n c r e a s e d , with the m a j o r i t y of animals r e q u i r i n g g r e a t e r i n t a k e s t o put on a k i l o g r a m of g a i n . R a t i o n c o s t s , f e e d c o n v e r s i o n s , and r a t i o n cost per k i l o g r a m of g a i n , are g i v e n i n Table V. Growth Curves Growth curves f o r a l l the r a t i o n s are not i n c l u d e d ; however, a r e p r e s e n t a t i v e curve p e r t a i n i n g to R a t i o n No. 1 i s g i v e n i n F i g u r e I . S i m i l a r growth curves were obt a i n e d on a l l r a t i o n s , with no major changes due to the o v e r - w i n t e r i n g p e r i o d or r a t i o n adjustments t h a t were made. Rat i o n Analyses The proximate analyses of the r a t i o n s used i s g i v e n i n Table V I . F e e d l o t A p p l i c a t i o n Feed e f f i c i e n c i e s were high and gains h i g h enough f o r a l l r a t i o n s t o demonstrate t h a t p r a c t i c a l a p p l i c a t i o n of a l l r a t i o n s t f e e d l o t o p e r a t i o n s i s p o s s i b l e . FIGURE I 400 h 2b ' 4b '6080 TOO r~T2o * 140 ' 160 " 180 ' 2CJ0 TIME (days) STUDY I TABLE V AVERAGE DAILY GAINS AND FEED EFFICIENCIES  (Nov. 21 - May 15) 175 days Ration No. Major Con-s t i t u e n t s % O v e r a l l A.D.G.-(kg) ( l b s ) O v e r a l l F.E.2 Average Feed Cost per 4 5 . 4 5 kg gain 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 10LS/78B 10S/78B 25S/60B 40S/42B 10S/6lB/l5Be 2 5 S / 4 7 B / l l B e 40S/33B/8Be 10S/82W 25S/63W 40S/44W 10LH/81B 10H/81B 25H/69B 40H/56B 10H/64B/l6Be 2 5 H / 5 1 B / l 3 B e 40H/44B/llBe 10H/86W 25H/73W 40H/60W 1.17 1.21 1.08 1.04 1.15 1.02 1.05 1.14 1.11 1.04 1.24 1 .31 1.18 1.15 1 . 2 5 1 . 2 4 1.26 1.15 1.18 1.18 2.59 2.68 2.38 2.30 2.53 2.25 2.33 2.52 2.45 2.30 2.73 2.89 2.61 2.53 2.76 2.73 2.78 2.53 2.61 2.60 6.34 6.11 6.39 7.04 6.80 7.10 6.65 5.70 6.15 6.19 5.05 5.18 5.43 6.70 5.11 5.78 6.12 6.18 5.61 5.51 $19.08 18.39 19 . 17 21.06 21.42 22 .13 20.38 18.73 19.75 19.53 14.90 15.29 15.18 17.81 15.81 16.89 16.84 16.55 16.74 16.65 x A.D.G. - Average D a i l y Gain = F i n a l Wt. - I n i t i a l Wt. 175 days 2 F.E. - Feed E f f i c i e n c y (kg feed/kg of gain) L - denotes long form as against chopped H - Hay B. - Bar l e y W - Wheat S - Straw Be - Beet Pulp STUDY I TABLE V'l PROXIMATE ANALYSES OF RATIONS (dry matter basis) Ration Major Con- Crude Crude Crude Ash % G.E.2 No. stituents % Protein % Fibre % Fat % Ca % N.F.E. % KCal/kg 1 1 0 L S / 7 8 B 1 6 . 2 2 1 0 . 6 7 2 . 4 9 2 . 2 3 . 0 6 5 6 . 0 6 4 . 6 2 4 2 10S/78B 1 6 . 2 2 1 0 . 6 9 2 . 4 9 3 . 2 3 . 0 6 6 7 . 3 2 4 . 3 2 3 3 2 5 S / 6 0 B 1 6 . 0 1 1 7 . 8 4 2 . 4 1 4.15 . 0 9 5 9 . 4 6 4 . 5 9 2 4 4 0 S / 4 2 B 15 .95 25 . 0 1 2 . 3 1 5 . 0 7 . 1 2 51 .6 4 . 5 5 0 5 1 0 S / 6 l B / l 5 B e 2 5 S / 4 7 B/llBe 1 6 . 1 7 1 3 . 2 4 2.18 4 . 1 9 . 1 1 64.14 4 . 6 4 3 6 1 6 . 1 4 19.81 2 . 1 5 4.89 . 1 2 5 6 . 9 1 4 . 6 0 4 7 40S/33B/8Be 1 5 . 9 2 6 . 3 9 2 .13 6 . 7 0 . 1 4 4 3 . 9 0 4 . 5 6 7 8 10S/82W 1 5 . 7 1 9.89 2 . 2 4 3 . 2 4 . 2 3 57.51 4 . 2 0 3 9 2 5 S / 6 3 W 15.61 1 7 . 6 0 2 . 3 2 4.86 . 2 3 5 5 . 6 9 4 . 0 1 3 1 0 4 0 S / 4 4 W 16.80 2 5 . 3 2 2.08 6 . 0 6 . 2 3 51 . 4 2 4 .857 1 1 10LH/81B 1 6 . 1 9 8 . 7 4 2 . 4 9 2 . 5 4 . 1 9 5 7 . 1 6 4 . 5 9 6 1 2 10H/81B 1 6 . 1 9 8 . 7 4 2 . 4 9 2 . 5 4 . 1 9 5 7 . 1 6 4 . 5 9 6 13 2 5 H / 6 9 B 15 . 4 2 1 3 . 0 2 2.41 2 . 3 9 . 3 9 51.14 4 . 5 2 4 1 4 4 0 H / 5 6 B 1 4 . 8 3 1 7 . 2 8 2 . 3 2 2.25 .60 4 9 . 7 8 4 . 4 5 1 15 1 0 H / 6 4 B / l 6 B e 16 . 12 1 1 . 4 0 2 . 1 7 3.54 . 2 3 5 4 . 6 4 4.616 16 2 5 H / 5 1 B/I31e 4 0 H / 4 4 B / l l B e 1 5 . 4 2 15.28 2 . 1 3 3 . 2 4 . 4 3 5 1 . 3 7 4 . 5 4 1 1 7 1 4 . 7 0 1 9 . 1 4 2 . 0 9 2 . 9 4 . 6 3 4 8 . 1 3 4 . 4 6 6 18 10H/86W 15 . 4 3 7.44 2 . 0 4 2 . 5 4 . 1 7 5 8 . 0 1 4 . 2 1 6 1 9 25H/73W 1 3 . 9 7 1 1 . 8 9 2 . 0 2 2 . 3 8 . 4 6 5 5 . 2 7 3 . 8 5 8 2 0 40H/60W 1 4 . 3 1 16 . 3 8 2 . 0 1 2.25 . 7 1 5 0 . 3 4 3 . 9 0 7 1 2 Nitrogen Free Extract Gross Energy L - denotes long form as against chopped H B W s Be Hay Barley Wheat Straw-Beet Pulp (b) Carcass T r i a l The r e s u l t s of the c a r c a s s i n f o r m a t i o n are g i v e n i n Table V I I . Of the animals, 97 graded " c h o i c e " , and 3 graded "good". The o v e r a l l averages were: Mean Range Sh i p p i n g Weight 473 kg 3 8 9 - 5 4 1 kg Dressed Weight 274 kg 2 4 0 - 3 1 7 kg D r e s s i n g $ 5 7 . 3 $ 5 4 . 8 - 6 1 . 9 $ Rib Eye Measurement 6 7 . 7 2 sq cm 4 3 . 5 3 - 8 2 . 2 3 sq cm Fat Cover Average 2 . 0 3 cm 1 . 2 7 - 3 . 3 0 cm The f a c t t h a t 97$ of the animals i n v o l v e d i n t h i s study s t i l l managed t o f a l l w i t h i n one grade c l a s s i f i c a t i o n under the Canada Depart-ment of A g r i c u l t u r e Beef Carcass Grading, p r i o r t o September 5 , 1 9 7 2 , p o i n t s out the apparent i n a c c u r a c y of the system. I t appears t h a t t h e r e i s l i t t l e or no c o r r e l a t i o n between the l e a n meat i n kilograms i n a c a r c a s s and the grade o b t a i n e d . Only one animal o f the 3 t h a t graded "good" a f f e c t e d the range f i g u r e s at a l l , and i t d i d not a f f e c t them a d v e r s e l y . T h i s c a r c a s s had both the l e a s t f a t cover and the l a r g e s t r i b eye measurement. STUDY I TABLE V I I PEN AVERAGE DRESSING PERCENTAGES. RIB EYE AND FAT COVER MEASUREMENTS Ration Major Con- Dressing Rib Eye Fat Cover No. s t i t u e n t s % fo sq cm sq inches cm inches 1 10LS/78B 57.7 61.2 9.5 2.28 .9 2 10S/78B 58.3 66.4 10.3 2.03 .8 3 25S/60B 56.9 66.4 10.3 1.77 .7 4 40S/42B 55.8 67.7 10.5 1.52 .6 5 10S/6lB/l5Be 25S/47B/llBe 57.8 70.9 11.0 2.28 .9 6 57.7 69.0 10 .7 2.03 .8 7 40S/33B/8Be 56.5 66.4 10.3 2.03 .8 8 10S/82W 58.4 66.4 10.3 2.03 .8 9 25S/63W 57.5 74.1 11.5 1.77 .7 10 40S/44W 57.5 69.6 10.8 1.77 .7 11 10LH/81B 57.8 69.6 10.8 1.77 .7 12 10H/81B 58.7 64.5 10.0 2.28 .9 13 25H/69B 57.6 69.6 10.8 2.03 .8 14 40H/56B 58.1 72.2 11.2 1.77 .7 15 10H/64B/l6Be 58.1 69.O 10 .7 2.28 .9 16 25H/51B/l3Be 58.2 67 .7 10.5 2.28 .9 17 40H/44B/llBe 57.9 67 .7 10.5 2.03 .8 18 10H/86W 59.2 70.9 11.0 2.28 .9 19 25H/73W 59.4 67 .7 10.5 2.28 .9 20 40H/60W 58.5 66.4 10.3 2.03 .8 L - denotes long form as against chopped H - Hay S - Straw B - Barley Be - Beet Pulp W - Wheat I t should be noted t h a t the animals t h a t consumed the r a t i o n s having 40% roughage (4, 7, 10, 14, 17, 20) had l e s s than average f a t cover. Those t h a t were o f f e r e d r a t i o n s 4, 7, 10 (40% straw), had a r i b eye measurement of l e s s than the average (Table V I I ) . R a t i o n s 14, 17, 20, contained 40% hay. D i g e s t i b i l i t y T r i a l There seems to be an i n d i c a t i o n t h a t the hi g h roughage r a t i o n s (40%), i . e . r a t i o n s 4, 7, 10, 14, 17, 20, had a lower dry matter d i g e s t -i b i l i t y . The r e s u l t s of the t r i a l are gi v e n i n Table V I I I . T h i s t r i a l encountered numerous problems which e x p l a i n why t h e r e were not two animals used on each r a t i o n as shown i n Table V I I I . STUDY I TABLE VIII AVERAGE DRY MATTER DIGESTIBILITIES Ration No. Major Con-stituents % Animal 1 Animal 2 Average Dry Matter D i g e s t i b i l i t y % 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 10LS/78B 10S/78B 25S/60B 40S/42B 10S/6lB/l5Be 25S/47B/llBe 40S/33B/8Be 10S/82W 25S/63W 40S/44W 10LH/81B 10H/81B 25H/69B 40H/56B 10H/64B/l6Be 25H/51B/l3Be 40H/44B/llBe 10H/86W 25H/73W 40H/60W 8 2 . 9 7 9 . 2 7 5 . 2 6 9 . 9 7 3 . 1 2 7 3 . 3 7 7 5 . 9 8 , 7 2 . 0 9 #64.27 7 5 . 6 5 7 4 . 4 1 7 1 . 6 1 7 2 . 0 4 6 9 . 0 9 7 4 . 9 5 7 2 . 4 5 7 0 . 9 2 7 9 . 4 3 ,,80.52 ^ 6 4 . 9 1 77.3 6 9 . 4 7 4 . 2 7 4 . 1 6 7 1 . 0 4 31 .76 7 5 . 6 7 7 5 . 7 0 7 4 . 2 4 ,71.39 #61.61 6 9 . 9 0 7 5 . 2 4 7 2 . 6 0 81.28 76.08 8 0 . 3 5 7 4 . 3 7 4 . 7 6 9 . 9 7 3 . 6 4 72 .45 7 8 . 8 7 7 2 . 0 9 6 9 . 9 7 7 5 . 6 7 7 4 . 3 2 71 .50 6 6 . 8 2 6 9 . 4 9 7 5 . 0 9 7 2 . 4 5 7 1 . 7 6 8 0 . 3 5 8 0 . 5 2 7 0 . 4 9 Poor c o l l e c t i o n L - denotes long form as against chopped H B - Barley W S - Straw Be Hay Wheat Beet Pulp STUDY I I THE EFFECT OF VARIOUS FEED GRAINS ON THE GROWTH PATTERNS OF GROWING AND FATTENING STEERS A. INTRODUCTION Study I I i n v o l v e d a f e e d i n g t r i a l u s i n g Hereford s t e e r s and r a t i o n s which v a r i e d i n content, w i t h b a r l e y , wheat, and corn, being compared. Two of the major c o n s i d e r a t i o n s i n d e t e r -mining what c o n s t i t u e n t s w i l l make up a concentrate i n any p a r t i c u l a r area are economics and c o s t . For example, corn i s an expensive f e e d c o n s t i t u e n t i n the lower F r a s e r V a l l e y and i s , t h e r e f o r e , not used to any extent i n l o c a l commercial f e e d l o t s . However, i t can not be ignored from a r e s e a r c h p o i n t of view simply because of c o s t . Canada Ts g r a i n s i t u a t i o n i s changing r a p i d l y because of world t r a d e and ever-expanding markets. I f Canada i s to take f u l l advantage of these expanding markets, r e s e a r c h must be done wit h g r a i n s produced both here and elsewhere so t h a t the r e l a t i v e value of Canadian g r a i n s can be e s t a b l i s h e d reasonably a c c u r a t e l y . Energy c o n c e n t r a t i o n and i n t a k e determine the a b i l i t y of a f e e d g r a i n t o produce r a p i d and economical g a i n s . On a pound f o r pound b a s i s , high-energy f e e d g r a i n s w i l l produce more beef at lower c o s t s than do low-energy f e e d s . T h e r e f o r e , i n the d i s c u s s i o n and r e s u l t s p a r t of t h i s study, a c l o s e look w i l l be taken at the energy e v a l u a t i o n of the s i x r a t i o n s used. A l s o , i t i s r e c o g n i z e d t h a t a s h i f t i n the g e o g r a p h i c a l s e t t i n g of t h i s study would completely a l t e r or change the economic a p p r a i s a l of these r e s u l t s . However, the primary aim of t h i s study was to compare the value o f corn, b a r l e y and wheat as b a s a l g r a i n s , and t o i n v e s t i g a t e the p o s s i b l e value o f mixing the g r a i n s i n v a r i o u s p r o p o r t i o n s . The c r i t e r i a c o n s i d e r e d were, average d a i l y g a i n , f e e d e f f i c i e n c y , c ost per k i l o g r a m of g a i n , c a r c a s s grade, and d r e s s i n g percentage. A secondary c o n s i d e r a t i o n i n the study was the economic f e a s i b i l i t y o f any one r a t i o n com-pared t o the o t h e r s . A l s o c o n s i d e r e d i n t h i s study was the c a r c a s s e v a l u a t i o n i n terms of use to the consumer. B. LITERATURE REVIEW When comparing the f e e d i n g v a l u e s of d i f f e r e n t g r a i n s , one very important c h a r a c t e r i s t i c t o examine i s the energy content. Corn, b a r l e y , and wheat, are a l l r e l a t i v e l y h i g h i n energy content. However, b a r l e y c o n t a i n s about 5% l e s s net energy than does wheat or corn. The g e n e r a l i z e d breakdown o f average energy u t i l i z a t i o n i n a f e e d f o r ruminants i s g i v e n i n F i g u r e I I . There are s e v e r a l systems f o r e v a l u a t i n g feeds on an energy b a s i s , with the f o l l o w i n g systems being most w i d e l y used i n North America: 1. D i g e s t i b l e Energy 2. T.D.N, or T o t a l D i g e s t i b l e N u t r i e n t s 3. Net Energy-Maintenance and Prod u c t i o n Of the systems used i n the past the most common was the T o t a l D i g e s t i b l e N u t r i e n t system (TDN). The Net Energy system was a refinement o f the TDN system. By i t s d e f i n i t i o n , net energy r e f e r s t o t h a t p a r t o f the energy o f the f e e d which i s a v a i l a b l e to support maintenance, milk p r o d u c t i o n o r growth. I t was an improvement over the TDN system and i t s use has per-m i t t e d improvement i n the f e e d i n g management o f ruminants. S T U D Y I I F I G U R E I I 4 2 . E N E R G Y R E L A T I O N S H I P S - F E E D G R O S S E N E R G Y R U M E N G A S £ U R I N E L O S S - M E T A B O L I Z A B L E E N E R G Y - F E C A L D I G E S T I B L E E N E R G Y G R O W T H OR F A T M I L K R U M E N F E R M E N T A T I O N H E A T O F N U T R I E N T M E T A B O L I S M N E T E N E R G Y • M A I N T E N A N C E H E A T O F R U M E N W T . M A I N T E N A N C E N U T . F E R M E N - M E T H A N E U R I N E G A I N M I L K E N E R G Y M E T A B . T A T I O N L O S S L O S S F E C E S c-<-<-<-<-— G R O S S E N E R G Y — D I G E S T I B L E E N E R G Y > — M E T A B O L I Z A B L E E N E R G Y > — N E T E N E R G Y -> Jp v S. MTT _. N E n - > <— N E m NEp - Net Energy P r o d u c t i o n NE m - Net Energy Maintenance Source Cardon (1970) Net energy w i l l be used f o r a l l c a l c u l a -t i o n s throughout t h i s paper. T h i s net energy system used i n the growing and f i n i s h i n g phases of beef c a t t l e was i n t r o d u c e d by Lofgreen et a l i n I963. T h i s system separates the requirements f o r maintenance from t h a t f o r body weight g a i n , and expresses a net energy v a l u e o f the f e e d f o r these two f u n c t i o n s . NE m r e p r e s e n t s the net energy requirement and the net energy content o f the f e e d when used f o r maintenance. NEg r e p r e s e n t s the net energy used f o r p r o d u c t i o n o f weight g a i n . Net energy f o r maintenance i s e s t a b l i s h e d on the b a s i s t h a t NE m requirement f o r both s t e e r s and h e i f e r s i s equal to approximately 0.077 Meals per u n i t o f metabolic body s i z e (wO«75kg). The energy d e p o s i t e d i n weight g a i n o f s t e e r s (the NEg requirement) i s r e p r e s e n t e d by the equation NEg = (52.72 g a i n + 6.84 g a i n 2 ) ( W ° - 7 5 k g ) . NE valu e s are a l s o u s e f u l i n determining whether c a t t l e have gained weight i n accordance with e x p e c t a t i o n s . When NE requirements are separated i n t o maintenance and body weight g a i n , they do not vary when d i f f e r e n t roughage/concentrate r a t i o s are f e d , as do ME and TDN requirements. The standard t a b l e s o f Feed Composition NRC 1959, M o r r i s o n , 1956, i n d i c a t e d t h a t corn was s l i g h t l y s u p e r i o r t o b a r l e y on a TDN or a c a l c u l a t e d net energy b a s i s . Many r e s e a r c h e r s n o t i c e d , however, t h a t b e t t e r g a i n s and f e e d e f f i c i e n c y were obtained with b a r l e y . Hale et a l (I962), r e p o r t e d t h a t b a r l e y showed a 5% i n c r e a s e i n d a i l y g a i n , with a 8.7% decrease i n fe e d r e q u i r e d when compared t o cor n . G a r r e t t et a l (1964) r e - e v a l u a t e d b a r l e y and corn net energy v a l u e s . T h e i r r e s u l t s i n d i c a t e d t h a t b a r l e y and corn, o r a 50-50 mixture of these g r a i n s , are approximately equal i n t h e i r net energy content. T h e r e f o r e , t h e r e should be no reason f o r f e e d e r s t o d i s c r i m i n a t e a g a i n s t corn as a source o f energy when f e d i n a balanced r a t i o n . The problem o f d e s c r i b i n g the o v e r a l l a v a i l a b l e energy value o f feeds i s somewhat the same as t h a t of d e s c r i b i n g the n u t r i t i v e worth of the p r o t e i n complex. The worth o f a fe e d g r a i n as a source o f p r o t e i n q u a l i t y i s dependent on two f a c t o r s , the t o t a l c o n c e n t r a t i o n o f the p r o t e i n s and the d i s t r i b u t i o n o f the amino a c i d s making up the p r o t e i n s . Since the body c o n t a i n s many d i f f e r e n t p r o t e i n s having d i f f e r e n t amino a c i d r e l a t i o n s , the u s e f u l n e s s o f a f e e d g r a i n depends, i n p a r t , on the purpose f o r which i t i s f e d . For example, fewer amino a c i d s are needed f o r maintenance than f o r r a p i d growth. The u s e f u l n e s s o f the p r o t e i n o f a p a r t i c u l a r r a t i o n i n meeting the animals' p r o t e i n ( n i t r o g e n ) needs i s o f t e n r e f e r r e d t o as i t s q u a l i t y . Although net energy v a l u e s f o r corn have been estimated at s e v e r a l s t a t i o n s , t h e r e i s s t i l l c o n s i d e r a b l e l a c k o f agreement. Vance et a l (1972) t h e o r i z e d t h a t t h i s v a r i a t i o n i s due to a number o f f a c t o r s , i n c l u d i n g temperature o r environment ( G a r r e t t et a l 1 9 6 4 ) , the breed o r sex o f c a t t l e ( H a l l et a l 1 9 6 $ , Klosterman et a l 1968), and the method of determining net energy. A l s o , there i s s t i l l c o n t r o v e r s y r e g a r d i n g the a s s o c i a t i v e e f f e c t s of i n d i v i d u a l feeds i n mixed r a t i o n s . B l a x t e r et a l (1964) concluded " t h a t the net energy o f a food d e t e r mined by adding i t to a b a s a l d i e t i s not constant but v a r i e s w i t h the l e v e l o f f e e d i n g adapted and the nature o f the b a s a l d i e t " . G r i n d i n g has long been recommended f o r corn g r a i n i n f i n i s h i n g r a t i o n s . Recent f e e d l o t r e s e a r c h has suggested t h a t whole s h e l l e d corn can be s a t i s -f a c t o r i l y f e d (Hixon et a l 1 9 6 9 , Burkhardt et a l 1969 McLaren et a l 1 9 7 0 , Gerken et a l 1 9 7 1 ) . Corn and b a r l e y were used and compared i n t h i s f e e d i n g t r i a l because of the i n d i c a t e d r e s e a r c h and the world-wide r e c o g n i t i o n o f corn o r maize as a g r a i n crop. Although i t appears (FAO 1971) t h e r e w i l l be l e s s wheat a v a i l a b l e i n the f u t u r e f o r animal f e e d i n g o r beef p r o d u c t i o n , i t was used and compared i n t h i s t r i a l because of i t s use and r e c o g n i t i o n throughout the world as an important g r a i n crop. While c a r c a s s data were gathered i n t h i s study f o r comparison purposes between r a t i o n s , i t i s a l s o n o t a b l e t h a t a g r e a t d e a l of r e s e a r c h i s c u r r e n t l y being done i n Canada, e s p e c i a l l y with regard to the beef g r a d i n g system used. The g r a d i n g system i n use i n Canada d u r i n g t h i s study c o n t a i n s a g r e a t d e a l of mythology as does the merchandising of beef to the consumer. The c u r r e n t g r a d i n g system does not a c c u r a t e l y p r e d i c t the q u a n t i t y or q u a l i t y of the l e a n meat w i t h i n a c a r c a s s . The proposed new g r a d i n g system (September 1972) w i l l attempt to p r e d i c t more a c c u r a t e l y c a r c a s s value i n l i g h t o f r e c e n t r e s e a r c h . One example of the c a r c a s s r e s e a r c h i s the q u e s t i o n of beef tenderness and b u l l meat. Pearson (1966) showed t h a t tenderness i s g e n e r a l l y accepted as the most important s i n g l e a t t r i b u t e c o n t r i b u t i n g t o the a c c e p t a b i l i t y of beef. I t has l o n g been assumed t h a t f a t n e s s , both e x t e r n a l i n the form o f f i n i s h , and i n t r a - m u s c u l a r i n the form of marbling, was r e l a t e d t o tenderness. The q u e s t i o n of prime importance was whether marbling and c a r c a s s f a t are b a s i c r e q u i s i t e s f o r meat tenderness, or whether tenderness i s p r i m a r i l y a f u n c t i o n of animal age and 47. o t h e r f a c t o r s . In a d d i t i o n t o animal age, the degree of c a r c a s s ageing r e q u i r e s s p e c i f i c a t i o n . M a r t i n et a l (1970) suggested t h a t the e n t i r e r e l a -t i o n s h i p between tenderness and other quality-f a c t o r s , and marbling and f a t n e s s i n r e l a t i o n to sex, ageing p e r i o d , m a t u r i t y , r e q u i r e s compre-hensive e v a l u a t i o n . They thought t h i s t i m e l y due t o c u r r e n t trends toward s l a u g h t e r i n g of younger c a t t l e and i n c r e a s i n g i n t e r e s t i n y i e l d g r a d i n g f o r beef c a r c a s s e s . M a r t i n et a l (1970) concluded " I n s o f a r as the p o p u l a t i o n i n the present study was concerned, f i n i s h o r ot h e r f a t n e s s measurements were u n r e l a t e d t o tenderness, while v a r i a t i o n i n marbling e x p l a i n e d o n l y 9% of the v a r i a t i o n i n ten d e r n e s s " . MATERIALS AND METHODS (a) Feeding T r i a l Experimental Design The experimental animals were randomly a l l o c a t e d t o twelve pens, f i v e animals i n each. Two pens were assigned to one of each of the s i x r a t i o n s . The animals were slaughtered when they reached a l i v e weight of 454-477 kilograms. Experimental Animals The experimental animals ( 6 3 Hereford s t e e r calves) were obtained from the B.C. Liv e s t o c k Producers' Co-operative A s s o c i a t i o n at M e r r i t t , B.C. and were s e l e c t e d on the b a s i s of uniform body weights and conforma-t i o n . The average weight of the animals on day 6 was 2 2 3 . 6 kilograms. The steers were a l l ear-tagged and a l l o c a t e d at random t o pens, f i v e animals i n each. Housing Housing was the same as th a t described i n Study I . 49. I n i t i a l Treatment and Feeding Procedure On a r r i v a l at the experimental f a c i l i t i e s (day 1 ) , the animals were f e d a l f a l f a - b e r m u d a g r a s s hay (long form). The animals were g i v e n i n j e c t i o n s of P r o v i t e 1 (1 cc.) (Vitamins A, D 2 and E ) , to prevent or c o r r e c t any v i t a m i n d e f i c i e n c i e s , and Rea-Plex (2 cc.) f o r p r e -v e n t i o n of i n f e c t i o u s bovine r h i n o t r a c h e i t i s . The animals were ear-tagged and randomly a s s i g n e d t o pens. The hay d i e t s continued through the adjustment p e r i o d . The g r a i n p r o p o r t i o n was g r a d u a l l y i n c r e a s e d and the roughage p r o p o r t i o n was decreased u n t i l at the r a t i o n formulas (Table I X ) . These r a t i o n formulas were met on day 3 7 . A l l s t e e r s were subcutaneously implanted w i t h 36 m i l l i g r a m s o f D i e t h y l s t i l b e s t r o l . DES was used because l i t e r a t u r e has i n d i c a t e d improved f e e d e f f i c i e n c i e s and r a t e s of g a i n . Source: 1 Ayerst L a b o r a t o r i e s D i v i s i o n o f A y e r s t , McKenna & H a r r i s o n L i m i t e d , Montreal, Quebec. F o r t Dodge L a b o r a t o r i e s Inc., F o r t Dodge, Iowa. STUDY I I TABLE IX RATION COMPOSITION AND COSTS ( a i r dry b a s i s ) R a t i o n No. Percentage o f Composition C o s t / 1000 kg Co s t / ton 1 90 Wheat/10 Hay $67.87 $61.70 2 90 Barley/10 Hay 57.97 52.70 3 90 Corn/10 Hay 94.60 86.00 4 74 Barley / l 6 Wheat/10 Hay 59.73 54.30 5 45 Barley/45 Wheat/lO Hay 62.92 57.20 6 74 Wheat/16 Barley/10 Hay 66.11 60.10 Note: A l l hay f e d i n chopped form. R a t i o n c o s t s p l u s $ .04 per head per day f o r V i t a m i n - M i n e r a l supplement. In a d d i t i o n to the i n d i c a t e d r a t i o n each animal r e c e i v e d .45 kg per day of the experimental V i t a m i n - M i n e r a l supplement. The d a i l y f e e d procedure d u r i n g the experiment i n v o l v e d f e e d i n g once per day, each morning. On days when the animals were to be weighed, f e e d was w i t h h e l d one hour u n t i l weighing was completed. The animals were f e d as much as they c o u l d consume i n 24 hours. Rations R a t i o n compositions and proximate a n a l y s i s data are g i v e n i n Tables IX and X. P r o t e i n and V i t a m i n - M i n e r a l Premix composition are g i v e n i n Table XI. Weighing Procedure Weighing was done bi-weekly. A f t e r being weighed a few times, the animals became accustomed t o the procedure and the o p e r a t i o n was done with a minimum of d i s t u r b a n c e to the s t e e r s . R a t i o n Costs Costs of a l l r a t i o n c o n s t i t u e n t s are gi v e n i n Table X I I . F l a k e d corn was the most expen-s i v e c o n s t i t u e n t a t # 9 2 . 0 0 per t o n . T h i s cost was l a r g e l y due to a v a i l a b i l i t y . R a t i o n c o s t s were again reasonably low c o n s i d e r i n g l o c a t i o n and s i z e o f experimental f a c i l i t i e s . Table XII a l s o g i v e s other c o s t s i n v o l v e d i n the experiment. STUDY I I TABLE X PROXIMATE ANALYSES OF FEEDSTUFFS Feedstuff Moisture % P r o t e i n % Crude F i b r e 1° Ash Fat % Energy Kcal/gm Barley- 13.0 11.3 8.4 2.7 3.1 4.228 Wheat 12.0 12.9 3.4 1.8 2.9 4.478 Corn 13.0 9.7 4.4 1.1 3.3 4.250 Hay 10.0 11.1 39.8 5.5 4.4 4.292 Vitamin-M i n e r a l Supplement 10.0 10.7 7.0 19.0 4.5 3.331 STUDY II TABLE XI COMPOSITION OF EXPERIMENTAL PREMIX Vitamin--Mineral Supplement Vitamin A - 1 4 0 gm ( 3 2 5 , 0 0 0 I.U. per gm) Vitamin D - 1 2 0 gm (80 m i l l i o n I.U. per lb) CuSO^ 4 0 gm C 0 S O 4 4 0 gm M n S 0 4 - 600 gm Z n S 0 4 - 1 0 0 0 gm Prodine - 36 gm ( 1 7 0 mg Iodine per gm) Experimental Premix (fed at . 4 5 kg per head per day) Vitamin Mix as above - 4 . 5 kg Limestone 63.6 kg Dicalcium Phosphate 4 5 . 4 kg Salt 7 2 . 7 kg Barley 618.1 kg Shorts 90.8 kg Tallow 13.6 kg Total 909 kg 5 4 . STUDY I I TABLE XII COSTS OF MATERIALS Steam R o l l e d B a r l e y | 6 0 . 5 0/ton (metric) ( $ 5 5 . 0 0/ton ( S h o r t ) ) F l a k e d Corn 1 0 1 . 2 0 " ( $ 9 2 . 0 0 » " ) Dry R o l l e d Wheat 7 1 . 5 0 » t t ( $ 6 5 . 0 0 " " ) Experimental Premix 9 1 . 3 0 " TT ( $ 8 3 . 0 0 » » ) Grass Hay 3 5 . 2 0 « TT ( $ 3 2 . 0 0 " " ) Other Costs S a l t B l o c k s 8 3 . 6 0/ton (metric) ( $ 7 6 . 0 0/ton (Short)) D i e t h y l s t i l -b e s t r o l implants 3 2 . 0 0 Drugs 1 5 0 . 0 0 Shavings -4 u n i t s 1 2 . 0 0 Ear Tags Re-usable C a t t l e 63 head $ 1 2 , 2 5 5 . 1 5 . (b) Management Procedures  Adaption The animals adapted e x c e e d i n g l y w e l l t o the r a t i o n s and the experimental environment. A l l were shipped d i r e c t l y from range c o n d i -t i o n s and, immediately upon a r r i v a l at the experimental f a c i l i t i e s , were s t a r t e d on s o l i d f o o d . A f t e r an i n c u b a t i o n p e r i o d o f 10-14 days, there was an occurrence of some s h i p p i n g f e v e r symptoms but these were e f f e c t i v e l y t r e a t e d w i t h a n t i b i o t i c s . Animal H e a l t h During the i n i t i a l adjustment of t h e animals to the r a t i o n s , one s t e e r d i e d (Nov. 29) due to b l o a t . The o n l y other major h e a l t h ^problem was the death of a second s t e e r on March 13th. The cause of death was unknown. However, t h i s time the suspected cause was malignant edema. At t h i s time, on March 16th, a l l remaining s t e e r s were t r e a t e d with 5 cc i n t r a m u s c u l a r l y of " C l o s t r i d i u m c h a u vei-septicum p a s t e u r e l l a bacterin"^-. The cost o f t h i s treatment was approximately $10.00 f o r the e n t i r e group. u r c e : 1 Norden L a b o r a t o r i e s , L i n c o l n , Nebraska. R a t i o n P r e p a r a t i o n A l l hay was f e d i n the chopped form and the v a r i o u s c o n s t i t u e n t s of the r a t i o n were not mixed p r i o r to f e e d i n g but simply weighed out and p l a c e d i n the f e e d trough. No adjustments were made i n the r a t i o n s a s i d e from minor changes w i t h i n batche of g r a i n . Carcass T r i a l The animals were s l a u g h t e r e d when they reached a l i v e weight o f 454-477 k i l o g r a m s . The f o l l o w i n g data were c o l l e c t e d : 1. Shipping Weight 2. Hot Carcass Weight 3. Government Grade. The s h i p p i n g weight of each animal was ob t a i n e d p r i o r t o i t l e a v i n g the experimental f a c i l i t i e s . Both the hot car c a s s weight and the government grade are a matter of procedure. The onl y arrange ment t h a t had to be made was f o r the e a r - t a g t o remain with the c a r c a s s . RESULTS AND DISCUSSION (a) Feeding T r i a l Average D a i l y Gains Average d a i l y gains were c a l c u l a t e d on a b a s i s of 14-day i n t e r v a l s throughout the 151 day t r i a l . The l a r g e s t average d a i l y gains were ob t a i n e d w i t h R a t i o n No. 6 (74% Wheat/16% B a r l e y / 1 0 % Hay) i n Pen No. 1 1 . However, s i n c e d u p l i c a t e s were run, i t i s p o s s i b l e t o o b t a i n an average of two separate pens of s t e e r s on each r a t i o n . The average r e s u l t s are g i v e n i n Table X I I I . I t i s i n t e r e s t i n g t h a t both R a t i o n No. 1 and R a t i o n No. 6 o b t a i n e d o v e r - a l l average d a i l y gains of 1 . 3 2 k i l o g r a m s . Feed Consumption D a i l y f e e d consumption per pen was recorded throughout the experiment t o a l l o w c a l c u l a t i o n o f o v e r - a l l f e e d e f f i c i e n c i e s as shown i n Tables XIV and XV. In Table X I I I i t can be seen t h a t R a t i o n No. 1 was the most e f f i c i e n t r a t i o n (90% Wheat, 10% Chopped Hay). 58. R a t i o n Cost per Kilo g r a m o f Gain In Table X I I I i t can be seen t h a t R a t i o n No. 2 (90$ B a r l e y / l 0 $ Hay) had the lowest cost per 45.45 k i l o g r a m o f g a i n at #16.50. Growth Data Growth curves are not presented because un i f o r m growth curves were obtained on a l l r a t i o n s . However, growth data f o r the e n t i r e t r i a l i s g i v e n i n Table XIV. Table XV a l s o presents the f e e d e f f i c i e n c i e s c a l c u l a t e d f o r the e n t i r e t r i a l . R a t i o n Analyses Proximate analyses data f o r the r a t i o n s used i s g i v e n i n Table XVI. 5 9 . STUDY II TABLE XIII AVERAGE DAILY GAINS AND FEED EFFICIENCIES Ration No. Major Con-stituents fo Overall (kg) A.D.G.1 (lbs) Overall F.E.2 Average Feed Cost per 45.45 kg gain 1 90W/10H 1.32 2.92 5.55 H7.13 2 90B/10H 1.27 2.81 6.26 16.50 3 90C/10H 1.20 2.65 6.01 25.88 4 74B/16W/10H 1.30 2.88 6.33 17.20 5 45B/45W/10H 1.16 2.56 6.24 17.86 6 74W/16B/10H 1.32 2 .92 5.83 17.54 A.D.G. - Average Daily Gain - F i n a l Wt. - I n i t i a l Wt. 151 days F.E. - Feed E f f i c i e n c y (kg feed/kg of gain) W - Wheat H - Hay B - Barley C - Corn STUDY I I TABLE XIV GROWTH DATA AVERAGE DAILY GAINS IN PERIODS OF TWO WEEKS (kilograms) Period 1 2 3 4 5 6 7 8 9 10 11 Pen 1 .82 1.50 1.63 1 . 4 8 1 . 3 8 1 . 4 4 1 .53 1.50 1 . 0 0 1 . 5 8 1 .23 2 . 7 2 1.51 1 .59 1 . 9 0 . 5 7 1 . 2 0 1 .16 1 . 6 2 1 . 3 8 1.12 1 . 2 7 3 . 5 2 1 .59 1 .96 1 .46 1 .06 1 . 0 7 1 . 4 5 1 .55 1.08 1.30 1.03 4 .80 1 .65 1.42 1 . 5 7 . 9 7 1 .12 1 .73 1 . 4 0 . 8 9 1.51 1.08 5 . 3 8 1 . 3 2 1 .51 1 .55 1 . 3 9 . 0 9 1 . 2 5 1 . 2 7 1 . 2 9 1 .41 1 . 2 7 6 . 6 2 1 .63 1 . 9 0 1 .56 1 .22 1.24 - 1.18 . 9 2 1 . 0 0 . 5 2 7 . 5 5 1.73 1 .74 1.80 1.12 1 . 6 2 . 8 4 1 . 4 0 1 . 3 5 1 . 3 5 1 . 0 6 8 . 9 0 1 .72 1.73 1 . 6 8 1 . 0 2 1.03 1 . 2 9 1 . 2 7 1.50 1 .23 0 . 0 9 .80 1 .62 1 .35 1 .41 1 . 0 6 1 . 3 6 .80 1 . 5 9 1 . 0 6 1.13 . 5 2 10 .81 1 .64 1 .47 1 .35 1.15 1 . 3 3 . 8 9 1 . 0 9 1 . 0 8 1 . 2 5 . 4 0 11 . 7 9 1.75 1 . 8 5 2 . 0 0 1 . 0 0 1 . 6 3 . 9 0 1.42 1.50 1.51 1 . 2 8 12 . 7 9 1 . 8 4 1 . 5 0 1 .23 1 .23 1 . 2 2 1 .13 1 . 10 1 .12 1 .12 1 . 18 STUDY I I TABLE XV  GROWTH DATA Feed E f f i c i e n c y - Kilograms of Feed/Kilograms o f Gain Period 1 2 3 4 5 6 7 8 9 10 s 11 Pen 1 5 . 4 3 3 . 7 4 4 . 1 4 4 . 8 0 5 . 8 4 5 . 6 9 5 . 4 8 5.80 8 . 8 6 5 .73 7 . 1 2 6.16 3 . 6 9 4 . 2 4 3 . 6 1 1 3 . 8 6 . 3 9 6 . 3 3 4 . 8 5 5 . 9 6 7 . 0 7 6 . 0 7 3 9 . 3 8 3.80 3 . 8 2 5 . 4 6 7 .66 7 . 5 9 6 . 0 7 6 . 0 6 8 . 6 5 7 .63 1 0 . 1 4 6 . 1 2 3 . 6 5 5 . 0 6 4 . 7 4 8.38 7.24 5 . 6 2 6 . 1 3 9.38 6 . 1 1 9 . 2 5 11 .5 3 . 9 2 4 . 2 7 4 . 7 1 5.80 7 . 8 5 6 . 1 5 6 . 1 6 6 . 0 2 5 . 8 9 6 . 6 6 7 . 9 1 3 . 7 1 3.80 4 . 8 1 6 . 8 3 6 . 4 9 - 5 . 2 1 8 . 3 5 8 . 0 4 1 3 - 4 7 8 . 9 4 3 . 4 8 4 . 3 3 4 . 6 9 8 . 2 7 6 . 4 9 1 0 . 2 6 6 . 1 4 6 . 8 5 7 . 3 7 9 . 8 8 5 . 4 2 3 . 5 1 4 . 1 9 4 . 7 7 8 . 3 5 8 . 3 7 7 . 0 7 . 4 6 6 . 4 5 8 . 0 6 _ 9 6 . 1 2 3 . 7 2 5 . 2 6 4 . 9 6 7 . 0 1 5 . 5 8 9 . 4 4 . 9 0 7 .25 7 . 3 4 1 5 . 0 10 6 . 0 3 3 . 6 8 4.80 5 . 3 0 6 . 4 7 5 . 6 6 8.58 7 . 2 6 7 . 0 4 6 . 4 9 -11 6 . 2 2 3 . 4 6 3 . 9 2 4 . 0 8.80 5 . 2 7 8 . 9 6 5 . 7 2 5 . 8 8 5 . 9 8 7 . 4 12 6 . 2 2 3 . 2 9 4 . 8 0 6.38 6 . 9 5 6.83 6 . 9 1 7 .14 7.13 7.08 6 . 9 STUDY I I TABLE XVI PROXIMATE ANALYSES OF RATIONS Ration No. Major Constituents % Moisture of Crude P r o t e i n % Crude F i b r e fo Crude Fat fo Ash fo Gross Energy Kcal/gm 1 90W/10H 11.8 12.7 7.04 3.05 2.17 4 . 4 5 2 90B/10H 12 . 7 11 . 2 7 11 . 5 4 3.23 2 . 9 8 4.23 3 90C/10H 12 . 7 9 . 8 3 7 . 9 4 3.41 1 . 5 4 . 4.25 4 74B/16W/10H 12 . 5 4 11.52 10 . 7 3 3 . 1 9 2.82 4.27 5 45B/45W/10H 12.25 11 . 9 8 9 . 2 9 3 . 1 3 2 . 5 7 4 . 3 4 6 74W/16B/10H 11 . 9 6 12 . 4 4 7 . 8 3 3.07 2 . 3 1 4.41 W - Wheat H - Hay B - Barley C - Corn Energy. As discussed i n the introduction of t h i s study, i t i s possible t h e o r e t i c a l l y to predict weight gains i f energy intake i s known. The NE m and NEg f o r growing and f i n i s h i n g steers are given i n Table XVII. The net energy concentration required of beef c a t t l e rations (dry matter basis) f o r f i n i s h i n g calves (250-450 kg body weight) i s 1.17 Mcal/kg of ra t i o n . Table XVIII shows the component parts of those feeds used i n the various rations tested. The t h e o r e t i c a l feed consumption of a 300 kg and 400 kg steer are given i n Table XIX. By using projected intakes and feed compositions from Nutrient Requirements of Beef Cattle (1970), the t h e o r e t i c a l weight gains were calculated. Table XX shows the results obtained. It can be seen i n t h i s Table that the actual r e s u l t s were very accurately predicted. It was noted, however, that the amounts of feed consumed by each animal were greater than the t h e o r e t i c a l value used. STUDY I I TABLE XVII NET ENERGY REQUIREMENTS OF GROWING AND FINISHING  BEEF CATTLE (Mcal/animal/day) Body Weight (kg) 100 200 300# 350 400 450# 500 NE m r e q u i r e d 2.43 4.10 5.55 6.24 6 .89 7.52 8.14 D a i l y Gain (kg) NE g a i n r e q u i r e d  S t e e r s 0 . 1 0.17 0.28 0.39 0.43 0 . 4 8 0.52 0.56 0 . 2 0.34 0.57 0 . 7 8 0 . 8 8 0.97 1.06 1 .14 0.3 0.52 0 . 8 7 1.18 1.33 1 . 4 7 1.61 1 . 8 4 0.4 0.70 1.18 1 . 6 0 1.80 1.99 2.17 2.34 0.5 0 . 8 9 1.49 2 . 0 2 2.27 2 . 5 1 2 . 7 4 2.97 0.6 1.08 1.81 2 . 4 6 2 . 7 6 3 .05 3.33 3 .60 0 . 7 1 . 2 7 2 . 1 4 2 . 9 0 3.26 3 .6O 3.93 4 .25 0 . 8 1 . 4 7 2 . 4 7 3 . 3 6 3-77 4.17 4 . 5 5 4-92 0.9 1 . 6 7 2.81 3.82 4 .29 4 .74 5.18 5.60 1 . 0 1 . 8 8 3.16 4 . 2 9 4 .82 5.33 5 . 8 2 6 . 2 9 1.1 2 . 0 9 3.52 4 .78 5 . 3 7 5.93 6 .47 7 .00 1 . 2 2 . 3 1 3 .88 5 . 2 7 5 . 9 2 6.55 7.14 7 .73 1.3 2 .53 4 .26 5.77 6 .49 7.17 7.82 8 . 4 6 1 . 4 2 . 7 6 4 . 6 3 6 . 2 9 7 . 0 6 7.81 8 . 5 2 9 .22 1 .5 2 . 9 9 5 . 0 2 6.81 7 . 6 5 8 . 4 6 9 . 2 3 9 . 9 8 Source: N u t r i e n t Requirements of Beef C a t t l e (1970) STUDY I I TABLE XVI I I NET ENERGY AND DIGESTIBLE PROTEIN VALUES OF FEEDS USED IN RATIONS NE m (Mcal/kg) NE e (Mcal7kg) D i g e s t i b l e P r o t e i n % Wheat 2 . 1 6 1.42 9 . 2 Barley- 1 . 9 3 1 . 2 9 8 . 2 corn 2.28 1.48 7.6 Grass Hay 1.26 .62 5.7 Experimental Premix 1.40 .81 7.0 Source: N u t r i e n t Requirements of Beef C a t t l e (1970) STUDY I I TABLE XIX THEORETICAL FEED CONSUMPTION 300 kg s t e e r - r e q u i r e s 5 . 5 5 Meal f o r NE m consumes 2 . 4 kg dry matter / 1 0 0 kg of body weight, or i n t h i s case, 7 . 2 kg dry matter/day o f 6 . 0 7 kg - concentrate . 6 7 kg - roughage . 4 5 kg - Experimental Premix 400 kg s t e e r - r e q u i r e s 7 . 5 2 Meal f o r NE m - consumes 2 . 1 kg dry matter / 1 0 0 kg of body weight or 9 . 4 kg dry matter/day o f 8 . 0 5 kg - concentrate . 8 9 kg - roughage . 4 5 kg - Experimental Premix Source: N u t r i e n t Requirements of Beef C a t t l e (1970) STUDY II TABLE XX THEORETICAL VERSUS ACTUAL GAINS Ration No. Major Con-stituents fo Theoretical Gain (kg) Actual Gain (kg) Difference Actual from Theoretical Gains (kg) 1 90W/10H 1.25 1.24 + .01 2 90B/10H 1.29 1.39 - .10 3 90C/10H 1.53 1.42 + .11 4 74B/16W/10H 1.47 1.57 - .10 5 45B/45W/10H 1.28 1.20 + .08 6 74W/16B/10H 1.51 1.61 - .10 W - Wheat H - Hay B - Barley C - Corn The need o f every l i v i n g c e l l f o r p r o t e i n i s w e l l e s t a b l i s h e d . Thus, animals d e p l e t e d i n p r o t e i n are known to be l e s s r e s i s t a n t to a number of d i s e a s e s , and t o have a lower a b i l i t y t o r e c o v e r q u i c k l y or t o develop immunity t o d i s e a s e s , than do p r o p e r l y nourished animals. In a d d i t i o n , the enzymes which d i g e s t the f e e d and h e l p i n i t s u t i l i z a t i o n i n the body, as w e l l as the v i t a l hormones which r e g u l a t e body r e a c t i o n s , are p r o t e i n i n n a t u r e . The q u a l i t y of a p r o t e i n depends on such f a c t o r s as amino a c i d make-up, i t s d i g e s t -i b i l i t y , and the amount of n o n - p r o t e i n n i t r o g e n i t c o n t a i n s . The p r o t e i n requirements g i v e n i n Table XXI are those f o r f i n i s h i n g s t e e r c a l v e s and are based on minimal needs f o r optimum p r o d u c t i o n . Some r e s e a r c h has i n d i c a t e d t h a t f e e d i n t a k e i n c r e a s e s and o v e r a l l performance improves when preformed supplemental p r o t e i n r e p l a c e s supplemental non-p r o t e i n n i t r o g e n i n c a t t l e r a t i o n s . Thus f e e d i n g more than the recommended l e v e l may be e c o n o m i c a l l y f e a s i b l e . P r o t e i n requirements are expressed on the b a s i s o f both t o t a l and d i g e s t i b l e p r o t e i n . R a t i o n d i -g e s t i b l e p r o t e i n percent (y) i s expressed as a function of rat i o n t o t a l protein percent (x) by the equation: y = 0.877 x minus 2.64 Carcass T r i a l The results of the carcass t r i a l are given i n Table XXII. When compared with the carcass t r i a l from Study I, i t can be seen that while the dressing percentage was e s s e n t i a l l y the same, the average shipping weight was l i g h t e r . This can be p a r t i a l l y explained by the dropping market at shipping time, combined with the fact that the c a t t l e were one month behind the cycle of the previous year. Those carcasses that were graded down were done so on a conformation basis. This was a r e f l e c t i o n of the general conformation and uniformity of the entire group as compared to Study I. STUDY I I TABLE XXI PROTEIN REQUIREMENTS FOR FINISHING STEERS Body Weight kg A.D.G. kg D a i l y Dry Matter kg T o t a l P r o t e i n kg Dig . P r o t e i n kg Calcium gm Phos-phorus gm Caro-tene mg V i t . A (thousands) I.U. 150 . 9 0 3 . 5 . 4 5 . 3 0 21 15 1 9 . 5 7 . 8 200 1 .00 5 . 0 . 6 1 . 4 1 23 17 27 . 5 1 1 . 0 300 1 .10 7 .1 . 8 7 . 5 8 26 19 3 9 . 5 1 5 . 8 400 1 .10 8 . 8 . 9 8 . 6 2 25 20 4 9 . 0 1 9 . 6 450 1 .05 9 . 4 1 . 0 4 . 6 7 21 21 5 2 . 0 2 0 . 8 Source: N u t r i e n t Requirements of Beef C a t t l e (1970) STUDY I I TABLE XXII RATION AVERAGE DRESSING PERCENTAGES R a t i o n No. Major Con-s t i t u e n t s % Shipping Wt. kg Dressed Wt. kg D r e s s i n g % 1 90W/10H 461 265 5 7 . 5 2 90B/10H 440 253 5 7 . 4 3 90C/10H 433 249 5 7 . 6 4 74B/16W/10H 453 260 5 7 . 4 5 45B/45W/10H 448 258 5 7 . 6 6 74W/16B/10H 457 263 5 7 . 4 W - Wheat H - Hay B - B a r l e y C - Corn 72. •>.SUMMARY AND CONCLUSIONS  STUDY I The e f f e c t s o f the roughage l e v e l s w i t h the conce n t r a t e sources on the d a i l y weight g a i n s , f e e d c o n v e r s i o n e f f i c i e n c i e s and c o s t s , can be summarized by r a t i n g the e f f i c i e n c y o f each r a t i o n when based on: 1. Average d a i l y g a i n s 2. Feed c o n v e r s i o n e f f i c i e n c i e s 3. Cost per k i l o g r a m o f g a i n 4. Cost per ton o f fe e d . A l l r a t i o n s used i n t h i s study c o u l d be a p p l i e d to commercial f e e d l o t o p e r a t i o n s . Gains were good on a l l r a t i o n s and c o s t s were low enough t o r e s u l t i n medium to e x c e l l e n t gains a t reasonable p r i c e s with d i g e s t i b l e d i s t u r b a n c e s at a minimum. T h i s study i l l u s t r a t e d the advantage i n f e e d i n g r a t i o n s c o n t a i n i n g a hig h concentrate to rough-age r a t i o to f i n i s h i n g beef s t e e r s . Performance i n terms of average d a i l y g a i n , r a t e o f g a i n , and f e e d e f f i c i e n c y , was s u p e r i o r i n those s t e e r s r e c e i v i n g a high concentrate to roughage r a t i o and decreased as conc e n t r a t e s decreased and roughages i n c r e a s e d . T h i s decrease i n p r o d u c t i o n can be a t t r i b u t e d t o a l o w e r i n g o f d i g e s t i b l e energy content, an i n c r e a s e i n f i b r e content, an i n c r e a s e i n bulk, and consequently, a r e d u c t i o n i n the r a t e o f passage of f e e d through the animal as roughage percentage i n c r e a s e d . In the f i n a l a n a l y s i s , the p r i c e s o f con-c e n t r a t e s and roughages i n r e l a t i o n t o the perform-ance expected from them w i l l determine what types and p r o p o r t i o n s t o use. However, i t appears t h a t i n commercial f e e d l o t s roughage l e v e l s would seldom r i s e above 10%. T h i s g e n e r a l i z a t i o n w i l l be d e a l t with f u r t h e r i n t h i s summary. STUDY I I The e f f e c t s o f the c e r e a l content on the d a i l y weight g a i n s , f e e d c o n v e r s i o n e f f i c i e n c i e s and c o s t s , can be summarized by r a t i n g the e f f i c i e n c y of each r a t i o n when based on: 1. Average d a i l y gains 2. Feed c o n v e r s i o n e f f i c i e n c i e s 3. Cost per k i l o g r a m o f g a i n 4. Cost per t o n of fe e d . A l l r a t i o n s used i n t h i s study c o u l d be a p p l i e d t o commercial f e e d l o t o p e r a t i o n s when judged by average d a i l y g a i n and f e e d e f f i c i e n c y . However, the corn r a t i o n must be excluded when one c o n s i d e r s c o s t / k g of g a i n . As mentioned e a r l i e r however, t h i s c ost s i t u a t i o n may be, i n f a c t , to the advantage of corn i n o t h e r areas and a c t as a detriment to e i t h e r b a r l e y or wheat. In the f i n a l a n a l y s i s of Study I I , the p r i c e s o f the v a r i o u s c e r e a l s i n r e l a t i o n to the performance expected from them w i l l determine what types and p r o p o r t i o n s to use. I t appears t h a t here i n the F r a s e r V a l l e y , however, the corn and wheat r a t i o n s would not be as e c o n o m i c a l l y f e a s i b l e as would a b a r l e y - o r i e n t a t e d r a t i o n . The l a r g e s t f e e d -l o t i n the F r a s e r V a l l e y i s c u r r e n t l y f e e d i n g a r a t i o n based on b a r l e y with corn s i l a g e added i n v a r y i n g amounts, depending on stage of f i n i s h of animals. GENERAL CONCLUSIONS Many very important developments have changed f e e d l o t o p e r a t i o n s i n Canada d u r i n g the course o f these s t u d i e s . As p o i n t e d out by such o r g a n i z a t i o n s as the Food and A g r i c u l t u r e O r g a n i z a t i o n o f the United N a t i o n s , our world p o p u l a t i o n i s i n c r e a s i n g r a p i d l y . Accompanying t h i s i s an i n c r e a s e i n the per c a p i t a i n t a k e o f beef. An e a r l i e r g e n e r a l i z a t i o n t h a t most commercial f e e d l o t s would not feed more than 10% roughage may not be t r u e i n the not too d i s t a n t f u t u r e . At t h a t time we may have t o change our c a t t l e so they can u t i l i z e waste m a t e r i a l r i g h t up to market weight. T h i s i s assuming t h a t g r a i n s w i l l have t o be used more e f f i c i e n t l y by other animals and, t h e r e f o r e , w i l l not be a v a i l a b l e i n such g r e a t q u a n t i t i e s f o r f i n i s h i n g beef c a t t l e . In September of 1972, the beef c a r c a s s g r a d i n g system i n Canada was changed. The main b e n e f i t o f the new gr a d i n g system, which came i n t o e f f e c t on September 5th, i s t h a t i t w i l l make p o s s i b l a more accurate d e s c r i p t i o n o f c a r c a s s e s from the p o i n t o f view of both q u a l i t y and q u a n t i t y . I t w i l l g i v e consumers a chance to i n d i c a t e the type o f c a r c a s s t h a t i s most i n demand, and t h i s c o u l d r e s u l t i n l e a n e r c a r c a s s e s . Q u a l i t y g r a d i n g under the new system w i l l be more ac c u r a t e than under the o l d because by k n i f e - r i b b i n g the c a r c a s s , the g r a d e r i s able to a p p r a i s e a c r o s s - s e c t i o n of the l e a n meat. Quantity measurements w i l l a l s o be more a c c u r a t e . Research has shown a c l o s e c o r r e l a t i o n between the t h i c k n e s s o f f a t at the 11th r i b and the percentage of l e a n meat i n the e n t i r e c a r c a s s . Graders w i l l measure the f a t t h i c k n e s s t o one-tenth of an i n c h and c l a s s i f y the c a r c a s s i n the appro-p r i a t e f a t l e v e l w i t h i n the q u a l i t y grade. Looking back to the c a r c a s s i n f o r m a t i o n i n Study I, i t i s seen t h a t f a t cover ranged from 0.5 inches t o 1.3 i n c h e s , y e t 97$ of the c a r c a s s e s f e l l w i t h i n one grade. T h i s ambiquity w i l l not happen w i t h i n the new g r a d i n g system. Producers should b e n e f i t from the new system to the extent t h a t they are a b l e to produce the type of c a r c a s s which commands a premium p r i c e on the market. Everyone from the producer to the r e t a i l e r w i l l have a much more p r e c i s e system f o r i d e n t i f y i n g and s e r v i n g consumer demand. In l i t t l e more than two months the new grading system i s doing what i t set out t o d o — t h e c a r c a s s e s w i t h h i g h r e t a i l y i e l d are b r i n g i n g more money r i g h t through the marketing t r a i n , and the ones which r e q u i r e a l o t of trimming and throw-away are being d i s c o u n t e d r i g h t through. Long and t a l l c a t t l e of a l l c l a s s e s are i n s t r o n g demand. There i s now more of a demand f o r b i g growthy y e a r l i n g s to go i n t o f e e d l o t s . There w i l l be a s t r o n g demand f o r long and t a l l b u l l s . E x o t i c cross-breds are s e l l i n g at the a u c t i o n s f o r premiums both as f e e d e r s and s l a u g h t e r animals. Anyone with documented growth and g a i n a b i l i t y i n breeding stock w i l l f i n d ready markets. These new grades c a l l f o r great changes i n both the f e e d i n g and breeding of c a t t l e , and t h i s w i l l be both d i f f i c u l t and expensive f o r some people to l e a r n . C a t t l e bred and f e d as they were i n both Study I and I I w i l l not be s u i t a b l e f o r the f u t u r e market, or at l e a s t not as a c c e p t a b l e as they were i n the p a s t . T h i s new system w i l l a l l o w a f e e d e r to c a p i t a l i z e t o a g r e a t e r extent on the v a l u e s of h y b r i d v i g o u r as obtained i n c r o s s b r e e d i n g . The f e e d e r has a l s o had the hormone DES removed from the l i s t o f drugs allowed. T h i s w i l l lower f e e d e f f i c i e n c i e s i n g e n e r a l and, as a r e s u l t , i n c r e a s e the cost of producing a pound of beef. The p o l l u t i o n - c o n s c i o u s p u b l i c , a s i d e f r o m a p p r o v i n g o f r e m o v a l o f s y n t h e t i c s f r o m f o o d , i s a l s o a p p l y i n g p r e s s u r e t o t h e c o m m e r c i a l f e e d e r r e g a r d -i n g e n v i r o n m e n t a l p o l l u t i o n a n d w a s t e d i s p o s a l . R e c e n t r e s e a r c h i n f e e d i n g w i l l u n d o u b t -e d l y be h e l p f u l t o t h e c o m m e r c i a l f e e d e r . How-e v e r , i t i s o n l y , one o f a l o n g l i s t o f c h a n g e s c o n f r o n t i n g h i m -new b e e f g r a d i n g s t a n d a r d s , r i s e i n b e e f c o n s u m p t i o n , new b e e f m a r k e t i n g s y s t e m s , p o l l u t i o n c o n t r o l s , management r e s e a r c h , l a r g e s e l e c t i o n o f new b r e e d s , h y b r i d v i g o u r , b e t t e r t r a n s p o r t a t i o n f a c i l i t i e s a n d m e t h o d s , c h a n g i n g w o r l d m a r k e t s , s y n t h e t i c meat. W h i l e many o f t h e g e n e r a l c o n c l u s i o n s d i s c u s s e d h e r e do n o t seem r e l e v a n t t o t h e s e s t u d i e s , a l l c h a n g e s c u r r e n t l y b e i n g made i n t h e i n d u s t r y must be c o n s i d e r e d b e c a u s e t h e y a f f e c t f u r t h e r r e s e a r c h i n t h e f u t u r e . The f i e l d o f b e e f c a t t l e f e e d i n g r e s e a r c h i s d a i l y b e c o m i n g more c o m p l e x a n d i n t e r e s t i n g . Association of O f f i c i a l A g r i c u l t u r a l Chemists (I960). O f f i c i a l Methods of Analysis. 9th e d i t i o n . Washington, D.C. Beeson, W.M. and Perry, T.W. ( 1 9 5 2 ) . Balancing the Nu t r i t i o n Deficiencies of Roughages f o r Beef Steers. J. Anim. S c i . 11:501-515. Blaxter, K.L. and Wainman, F.W. ( 1 9 6 4 ) . The U t i l i z a t i o n of the Energy of Different Rations by Sheep and Cattle f o r Maintenance and f o r Fattening. J. Agr. Res. 63 :113« Bradley, N.W. (1958). An Evaluation of Chromic Oxide as an Indicator f o r Determining D i g e s t i b i l i t y of Beef Cattle Rations. Ph.D. thesis, University of I l l i n o i s , Urbana. Burkhardt, J.D., Embry? L.B. and Luther, R.M. ( I 9 6 9 ) . Corn Grain Processing Methods f o r High Concentrate B;eef Cattle Diets. J. Anim. S c i . 2^:153 (Abstr.) Cardon B.P. (1970). A Feeding Program f o r Milking Dairy Cows - NE-Milk. Feedstuffs, Nov. 14, 1970. Crampton, E.W. and Lloyd, L.E. (1951). Studies with Sheep on the Use of Chromic Oxide as an Index of D i g e s t i b i l i t y of Ruminant Rations. J. Nutr. 45:319. Cu l l i s o n , A.E. (I96I). E f f e c t of Physical Form of the Ration on Steer Performance and Certain Rumen Phenomena. J. Anim. S c i . 20:478. Davenport E. (1897). On the Importance of the Physiological Requirements of the Animal Body; Results of an Attempt to Grow Cattle Without Coarse Feed. I l l i n o i s Agr. Exp. Sta. B u l l . 4^:362. 80. 1 0 . Ellenberger, H.B. and Schneider, B.H. ( 1 9 2 7 ) . Exercise as a Factor i n Digestion T r i a l s with Dairy Cows. Vermont Agr. Exp. Sta. B u l l . 2 6 2 . 1 1 . Food and Agriculture Organization of the United Nations ( 1 9 7 1 ) . Agriculture Commodity Projections 1970-1980. F.A.O. Rome, I t a l y . 1 2 . Garrett, W.N., Lofgreen, G.P. and Meyer, J.H. ( 1 9 6 4 ) . A Net Energy Comparison of Barley and Milo f o r Fattening C a t t l e . J. Anim. S c i . 2 ? : 4 7 0 . 13. Gerken, H.J., Wise, M.B. Harvey, R.W., and Barrick E.R. ( 1 9 7 1 ) . Whole Corn, Liquid Supplements and Polyethylene f o r Beef C a t t l e . J. Anim. S c i . 3 2 : 3 7 9 . (Abstr.) 14. Geurin, H.B., Williamson J.L. Thompson J.C., Wilcke, H.L. and Bethke, R.M. (1959). Rolled Common Barley Serves as Both Grain and Roughage fo r Fattening Steers. J. Anim. S c i . 18 :1489 (Abstr.) 15. Hale, W.H., Hubbert F. J r . Cadena, M. and Taylor, B. ( 1 9 o 2 ) . Milo-Barley Studies with Fattening Steers. J. Anim. S c i . 2 1 : 9 9 8 . (Abstr.) 16. H a l l , G.A.B., Absher, C.W., Totusek, R. and Tilman, A.D. ( I 9 6 8 ) . Net Energy of Sorghum Grain and Corn f o r Fattening C a t t l e . J. Anim. S c i . 22:165. 17. Haskins, B.R. Wise, M.B., Craig, H.B., Blumer, T.N. and Barrick, E.R. ( 1 9 6 9 ) . E f f e c t s of Adding Low Levels of Roughages or Roughage Substitutes to High Energy Rations f o r Fattening Steers. J. Anim. S c i . 2 £ : 3 4 5 . 1 8 . Hironaka, R. and Slen, S.B. ( 1 9 6 2 ) . The E f f e c t s of Feed Consumption on Rate and E f f i c i e n c y of Gain by Steers Fed on A l l Barley Ration. Can. J. Anim. S c i . 42:18. 81. 1 9 . Hixon D.L., H a t f i e l d , E.E. and Lamb, P.E. ( 1 9 6 9 ) . Comparison of Whole S h e l l e d Corn with Cracked Corn i n C a t t l e F i n i s h i n g D i e t s . J . Anim. S c i . 22:161. (Abstr.) 20. Huffman, C.F. (1928). Hay i s Necessary i n Rations of Dairy C a t t l e ; Unknown Factor Present i n Hay Needed to M a i n t a i n Health of Dairy C a t t l e . Michigan Exp. Sta. Quart. B u l l . 11: 1:3. 21. Klosterman E.W., Ockaman, H.W. and C h a h i l l , V.R. (1968). Net Energy of Ear Corn and Corn S i l a g e f o r Steers and H e i f e r s . J . Anim. S c i . 27:1166. (Abstr.) 22. Lofgreen G.P., Bath, D.L. and Strong, H.T. (19o3). Net Energy of Successive Increments of Feed Above Maintenance f o r Beef C a t t l e . J . Anim. S c i . 22:598. 23. McLaren, R.J., Matsushima, J.K., McCann, C P . , Brasher T.E., K e l l o g g , G.E. and Lake, R.P. (1970). Extruded Corn f o r Beef F i n i s h i n g Rations. J . Anim. S c i . J l : 2 4 9 . (Abstr.) 24. Morrison, F.B. (1956). Feeds and Feeding (22nd ed.) Morrison Pub. Co., I t h i c a , New York. 25. N a t i o n a l Academy of Sciences - N a t i o n a l Research C o u n c i l (U.S.) (1970). N u t r i e n t Requirements of Domestic Animals, No. 4. N u t r i e n t Requirements of Beef C a t t l e . 4th r e v i s e d ed., Washington, D.C. 26. N a t i o n a l Research C o u n c i l ( 1 9 5 9 ) . J o i n t United States-Canadian Tables of Feed Composition. Pub. 659. Washington, D.C. 2 7 . N o b l i t t , C.G., Hardison W.A., Huber, J.T. and Graf, G.C. (19o3). E f f e c t of Manual T o t a l C o l l e c t i o n of Feces Upon Nut r i e n t D i g e s t i b i l i t i e s . J . Dairy S c i . 4 6 : 6 7 . 82. 28. Pearson, A.M. ( I 9 6 6 ) . D e s i r a b i l i t y of Beef - Its Charact e r i s t i c s and Their Measurements. J. Anim. S c i . 2 5 : 8 4 3 - 8 5 4 . 29. Phar, P.A., Bradley, N.W., L i t t l e CO., Cundiff, L.V., Boling, J.A. (1971). Nutrient D i g e s t i b i l i t y Using Fecal Co l l e c t i o n Apparatus and Indicator Method f o r Steers Fed ad li b i t u m . J. Anim. S c i . 22: 6 9 5 - 6 9 7 . 3 0 . Richardson D. Smith, E.F., Baker, F.H. and Cox, R.F. (1961). E f f e c t s of Roughage-Concentrate Ratio i n Cattle Fattening Rations on Gains, Feed E f f i c i e n c y , Digestion and Carcass. J . Anim. Sci.. 20:316. 31. Schurch A.F., Lloyd, L.E., Crampton, E.W. ( I 9 5 O ) . The Use of Chromic Oxide as an Index f o r Determining the D i g e s t i b i l i t y of a Diet. J. Nutr. 4 1 : 6 2 9 - 6 3 6 . 32. Swan, H. and Lamming, G.E. (I969). Studies on the N u t r i t i o n of Ruminants. The E f f e c t of Maize Based Diets Containing up to 70% Ground Barley Straw on the Liveweight Gain and Carcass Composition of Yearling Steers. Anim. Prod. 11:203. 33. Vance, Robert D., Preston, R.L. C a h i l l , V.R. and Klosterman E.W. Net Energy Evaluation of Ca t t l e - F i n i s h i n g Rations Containing Varying Proportions of Corn Grain and Corn Silage. J. Anim. S c i . 24-:851. 34. Waldo, D.R., Coppack, C.E., Smith L.W., Moore, L.A. and Sykes, J.W. ( 1 9 6 I ) . Annual Report of S-45 Regional Committee on the Nutrient Evaluation of Forage Crops. U.S. D.A., Washington, D.C. 3 5 . White T.W. and Reynolds, W.L. (1969). Various Sources and Levels of Roughage i n Steer Rations. J. Anim. S c i . 2 8 : 7 0 5 . 

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.831.1-0101297/manifest

Comment

Related Items