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The assessment of forage production from irrigated pastures by means of beef cattle 1953

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THE ASSESSMENT OF FORAGE PRODUCTION FROM IRRIGATED PASTURES BY MEANS OF BEEF CATTLE -by- HUGH HAMPSON NICHOLSON A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN AGRICULTURE in the Department of ANIMAL HUSBANDRY We accept this thesis as conforming to the standard required from candidates for the degree of MASTER OF SCIENCE IN AGRICULTURE. Members of the Department of Anipiyt Husbandry THE UNIVERSITY OF BRITISH COLUMBIA October, 1953 A B S T R A C T The use of Irrigated Pastures for the production of beef cattle in British Columbia is a relatively new venture. That they have aaplace in the ranch ecomony of the province is appreciated when i t i s realized that the natural range resources are being used to their fullest extent at the present time. Irrigated pastures provide a means of inten- sification of production and permit increased beef output from the limited land areas available in the province. The various methods of estimating pasture production through the use of grazing animals have been investigated. These investigations indicate the need for accuracy of experimental procedure since the variables encountered are numerous. The production of forage from i r r i - gated pastures in IAS days was 4290.0 to 5011.8 pounds of total digest- ible nutrients per acre depending upon method used in calculation. The young succulent grasses and legumes encountered in i r r i - gated pastures are high in protein with a corresponding deficiency in carbohydrate. The use of high energy supplementation may be worthy of further investigation. The incident of bloat and foot rot in animals on orrigated pasture can be a problem. Correct management procedures and prompt treatment wil l assist in alleviating these problems. A C K N O W L E D G M E N T S The writer wishes to thank Dr. A.J. Mood, Associate Professor in the Department of Animal Husbandry for his direction and constructive criticism in the preparation of this Thesis. To Mr. T.G. Willis, Superintendent of the Canada Range Experiment Station, gratitude is expressed for permission to undertake the project as part of the Station research program. Thanks must also go to Mr. Willis for his assistance in the establishment of the pastures. To the numerous other people who assisted in gathering data on the pastures and the expressing of that data in written form, I tender my sincere thanks. -OoOoOoOoOoOoOoOoOoOoOoOoO- T A B L E OP C O N T E N T S I. INTRODUCTION p. 1,2 II. REVIEW OF LITERATURE p.3 - 21 £H. EXPERIMENTAL p. 22 A* Experimental Animals p.22 B. Animal Procedure p.22 C. Pasture Forage Assessment Procedure p.24 IV. RESULTS p.25-31 V. DISCUSSION p.32-36 VI. SUMMARY AND CONCLUSIONS p. 37,38. APPENDIX I. IRRIGATED PASTURE BACKGROUND p. 39-48 APPENDIX II. MANAGEMENT OF PASTURES p. 49,50 APPENDIX III. ESTABLISHMENT OF EXPERIMENTAL PASTURES p. 51-56 APPENDIX IV. ANIMAL DISEASES p. 57,58. APPENDIX V. PHOTOGRAPHS p. 59-62. BIBLIOGRAPHY -oOoOoOoOoOoOoOoOoOoOo- I. I N T R O D U C T I O N Irrigated lands have provided forage f o r beef ea t t i e i n B r i t i s h Columbia since the time of the e a r l i e s t ranch settlements. The forage has normally been recovered as hay and has been used f o r winter feeding* Some aftermath grazing i s practiced on these i r r i g a t e d lands during the f a l l months* 4 recent innovation has been the use of inte n s i v e l y managed i r r i g a t e d lands f o r summer grazing and fattening of beef animals* Interest i n such i r r i g a t e d pastures has been furthered by the findings of investigators i n the P a c i f i c Northwest States which suggest that the y i e l d of animal products per acre can be greatly expanded by such pastures* Approximately f i f t e e n m i l l i o n acres of forest grazing land and two m i l l i o n acres of open grassland comprise the grazing land p o t e n t i a l of B r i t i s h Columbia* Anderson (1952) estimates that t h i r t e e n m i l l i o n acres of open and forested grazing lands are being used and i t represents almost the entire actual grazing p o t e n t i a l * MacGillivray (1949) makes the following statement: "Though the province i s supposed to be capable of further expansion of i t s c a t t l e ranching and i t s sheep ranching, information supplied by the Grazing Branch of the Department of Lands and Forests would indicate that the unused areas of ranch land i n Br i t i s h . Col- umbia are very l i m i t e d i n extent* Muwh of the range land i s now over grazed and would probably be a more p r o f i t a b l e resource i f carrying fewer c a t t l e and sheep* u From these - 2 - e tat omenta i t appears safe to conclude that the open grasslands are at present being f u l l y u t i l i z e d and i n f a c t i n many oases are being over u t i l i z e d , . The available open grasslands are used i n the main f o r early spring and late f a l l grazing* The forest lands are used f o r summer grazing during July, August and September* I f i t can be shown that Irrigated pastures poss- ess the productive capacity suggested by other workers then such pastures may f u l f i l l i n a measure the apparent need f o r greater per acre p r o d u c t i v i t y . The i r r i g a t e d pastures i n i t i a t e d at the Canada Range Experiment Station, Kamloops, B r i t i s h Columbia, were designed to study'the fundamentals of plant and animal growth and t h e i r i n t e r - r e l a t i o n s h i p s * While the research project i s s t i l l i n i t s i n i t i a l stages, i t i s already possible to delineates c e r t a i n basio conclusions from t h i s early data* This study had as i t s primary objective the determination of suitable ways and means to assess pasture production through the use of beef animals. Such a method of assessment i s necessary to form a base upon which to b u i l d pasture research and pasture recom- mendations* -3 II. REVIEW OF LITERATURE The assessment of pasture production by means of grazing animals has been the subject of many technical communications. These have ranged from detailed observations of grazing behaviour (Tribe and Gordon (1953), Wordrop (1953), Taylor (1953)) to extensive laboratory studies designed to determine its digestibility and nutritive quality, (Crampton (1939), Algren (1947), Report (1952)). Before reviewing the literature relative to the various methods pro- posed for assessing pasture production, i t is perhaps well to examine the nutritive requirements of beef cattle relative to their stage of growth. On the basis of these requirements, i t should be possible to estimate the necessary production of pastures to sustain any given rate of gain. The National Research Council (U.S*a.) in their Recommended Nutrient Allowances for Beef Cattle (1950) l i s t the requirements for fattening yearling cattle. This information is presented in Table I. TABLE I t "NATIONAL RESEARCH COUNCIL RECOMMENDED NUTRIENT . . -ALLOWANCES FOR FATTENING. YEARLING CATTLE" Body- Expected Percent Per Digest- T o t a l C a l - Phos- Caro- T.D.N. Dry Mat Weight Dally Gain of Animal i b l e Digest- cium phorus tene per . per Pounda Pounds Live Weight Pounds Protein i b l e Grams Grams Mg. Pound Pound Pounds Nutrients Gain Gain Pounds 600 Average 3.0 18 1.3 11.5 20 17 36 5.22 8.18 700 f o r 3.0 21 1.4 13.5 20 18 42 6.14 9.54 800 period 2.8 22 1.5 14.0 20 19 48 6.64 10.00 900 22 2.7 24 1.6 15.5 20 20 54 7,04 10.91 1000 pounds 2.6 26 1.7 17.0 20 20 60 7.73 11.82 1100 d a l l y 2.4 27 1.7 17.5 20 20 66 7.95 12.27 Morrison*s (1949) recommendations (Table I I . ) f o r c a t t l e i n the same weight range appear to be appreciably below those of the National Research Council as recorded i n Table I . T A B L E I I . MDRRISON'S FEEDING STANDARD FOR FATTENING YEARLING CATTLE Weight; Dry matter Digestible Protein T.D.N. l h f i . N u t r i t i v e Ratio ' Net Energy-Therms 600 13,2-16,3 1,20-1,41 10,3-12.7 7.0-8.0 9.3 -11.5 700 15,2«18.3 1,41-1,60 12*0-14.4 7.0-8,0 11.0 -13,2 800 17.0-20*3 1.59-1.79 13.5«*16,1 7.0-8.0 12,6 -15.0 900 18.5-2108 1*79-1.94 14,8-17.4 7.0-8.0 13.9 -16.4 1000 19.7»22.9 1.87-2*06 15.9-18.5 7,0-8.0 14.9 «17,4 1100 20.8-24.0 1.99-2,17 16.9-19.5 7.0-8,0 15.9 -18,3 Unfortunately Morrison does not suggest the rate Of gain to be expected from the feeding l e v e l that he has recommended,hence i t may be reasonable to conclude that h i s lower recommendations are designed to produce a gain of less than the 2.2 pounds per day suggested by the National Research Council, Morrison's presentation also precludes the c a l c u l a t i o n of the dry matter or t o t a l d i g e s t i b l e nutrients required per unit of gain. Reference to Table I suggests that the e f f i c i e n c y of gain to be expected i n c a t t l e of the weight 800 pounds w i l l be 6,64 pounds of t o t a l d i g e s t i b l e nutrients and 10,91 pounds of dry matter per pound of body weight gain. From Morrison (1949) (Table 111) the average composition of pasture grasses and legumes can be estimated* I t may be i n t e r e s t i n g to determine i f the 800 pound animal mentioned above can consume the amounts of forage necessary to obtain 6*64 pounds of t o t a l d i g e s t i b l e nutrients and 10*91 pounds of dry matter per pound of body weight gain* T A B L E I I I . DRY MATTER, DIGESTIBLE NUTRIENTS AND NET ENERGY .„ , ,. ..IK -.PASTURE.PORAGE. (AFTER MORRISON) GRASSES "Total'Dry Matter.in Percent Pasture " • Grasses and Legumes from well grazed, F e r t i l e Pasture, 22.0 $o rthe m St at e s Fast.grasses and Legumes from well g r a z e d , f e r t i l e pasture, Southern States _ 25*1 Pasture grasses with small amt. legume from well grazed, f e r t i l e pasture, Southern States 22*0 To t a l Dig- e s t i b l e Nutrients i n Percent E s t . Net Energy 100 l b s . Therms 14*9 16*6 14*6 13*0 14*4 12*2 Average of Pasture Forage 23*0 15*3 13*5 This animal must consume 43*4 pounds of green forage to provide the necessary t o t a l d i g e s t i b l e nutrients to produce one pound of body weight gain* For 2*2 pounds of gain 95.48 pounds of green forage must be consumed. This amount of forage at 23 percent dry matter represents a dry matter intake of 21.9 pounds per day* Experimental work by Garrigua as reported by Crampton (1939)(Table IV)would tend to indicate that suoh a dry matter intake or what i s more import- ant such a green forage intake i s we l l within the realms of p o s s i b i l i t y f o r an animal weighing 800 pounds. The above c a l c u l a t i o n i s dependent f o r Its v a l i d i t y upon numerous ad hoc feeding t r i a l s as summarised by Morrison. An alternative approach to the same problem can be obtained from the f i e l d of energetics. For example, a reasonable approximation of the Cal o r i c intake required by an animal to make a specif io d a i l y gain can be determined by using Brody's (1945) Resting Metabolism data and Hacker's (1920) data on the composition of gains i n beef animals. The composition of the weight gain i s an important consideration. Brody has stated :wTwo animals may gain welghtc at d i f f e r e n t rates, yet gain energy at the same rate . This i s because some types of weight gain- involve greater energy storage per unit l i v e weight than others. For instance, one gram of protein gain i s necessarily associated with three grams of water gain. Moreover, the energy equivalent of one gram of f a t i s two and one quarter times one gram of p r o t e i n . Hence one gram of f a t gain i s C a l o r i c a l l y equivalent to about eight grams protein gain," T A B L E IV, WEIGHT OP ANIMAL AND DAILY DRY MATTER . PASTURE. HERBAGE.BY.FREELY GRAZING CONSUMPTION OF STEERS . . Steer Weight of Steers .No, Forage Grazed ..Individ- u a l l y Average Blue Grass s headed A l f a l f a % bloom Clover mixture \ bloom Dry Matter Consumed Indiy i d - .ually Average B C F 938 988 535 602 A l f a l f a fbloom A l f a l f a , f u l l bloom 618 A l f a l f a , f bloom 758 A l f a l f a , f u l l bloom 775 Blue grass, 5 weeks 364 Red Clover, mature 362 Red Clover, £ bloom 394 Blue grass, 5 weeks 584 Red Clover, mature 582 Red Clover, \ bloom 622: 963, 535 610 766 373 596 25 .8 13*1 12*3 10.5 10*2 12*0 12,0 10*4 12*3 13*9 12*6 19*7 16.7 19*5 12*3 10*3 12.0 12*2 16*3 Blue grass, 5 weeks 844 Red Clover, mature 834 Red Clover, \ bloom 862 847 14*4 19*5 17.5 17.1 (continued next page) -9- TABLE IV CONTINUED . Steer Weight of Steers Dry Matter Consumed No. Forage Grazed Individ- .Individ- : u a l l y Average u a l l y Average H Blue Grass, 5 weeks Red Clover, mature Red Clover, ^ bloom 940 942 963 948 21.7 25.0 22.0 22.9 Reed Canary mixture Brome Grass 410 470 440 7.4 8.5 7.9 Reed canary mixture Brome grass 505 600 552 14.8 14.3 14.5 Reed canary Brome grass 800 850 825 15.6 14.9 15.2 Reed canary Brome grass 745 815 780 15.0 12.5 13.7 Recalculation of Haeker's data (Table V) lends support to Brody's statement. I t should be noied that Brody has erred i n assuming that one gram of fat i s C a l o r i c a l l y equivalent to 2,25 grams of pro t e i n . This i s true i n the metabolizable energy sense but h i s context inf e r s that ho i s describing the gross energy gain of the animal. In such an event f a t contains approximately 9/5.65 Calories more than p r o t e i n . -10- T A B L E V: "CHANGES IN BODY COMPOSITION WITH CHANGES IN BODY WEIGHT." . Body weight l b s . Percent Protein C a l o r i e s / 100 Grama Percent Pat C a l o r i e s / 100 Grams Total Caloric Gain 100 16,88 95*4 3.41 32*4 127*8 200 15.12 85,4 4.73 45,9 131,3 300 15*32 86,6 9.17 87.1 173.7 400 15,77 89,1 8.63 81.9 171*0 500 15,89 89,7 11.41 108,4 198,1 600 15,75 89,0 12.22 116.1 205,1 700 15.43 87.2 13,76 130*7 217,9 800 15,96 90.2 15«73 149,4 239,6 900 15,10 85.3 20,59 195*5 280 e8 1000 14.93 84*0 23*54 223*6 307*6 1100 14,43 81*5 28*21 268.0 349.5 1200 14.49 81*9 29*27 278*1 360*0 1500 14.10 79*8 33,71 320.2 400,0 By u n i t i n g the data of these two workers M i l l s (1953) has evolved and established a feeding standard f o r fattening y e a r l i n g c a t t l e * M i l l s allowed no increment f o r movement of h i s animals. Since the animals used were confined to a small area and movement was kept to a minimum, the error i n Calories f o r Resting Metabolism would be at a minimum* Animals on pasture usually have f u l l freedom of movement, therefore a 12 percent increment has been added to - l i - the Resting Metabolism to allow f o r t h i s Movement* The work of Ritzman and Benedict (1938) would indicate that t h i s f i g u r e i s approximately corrects This information i s presented i n Table VI. below, T 4 B L E VI: "DISTRIBUTION OP ENERGY INTAKE OF ., , . . • . » . . • YEARLING CATTLE1* „ Body Resting "' Gain ( l j N e t C a l - Gain/ Net Cal- Weight Metabolism Expected o r i c Con- Day i n orio In- Calories Pounds/Day tent of Calories take re- 1 " Gain/tbi^ quired '"' per Day 500 6989 1.50 1100 1650 8639 525 7163 1.58 1150 1817 8980 550 7336 1.65 1170 1921 9257 575 7514 1«73 1250 2163 9677 600 7692 1.80 1320 2376 10068 625 7862 1.88 1400 2632 10494 650 8030 1.95 1450 2828 10858 675 8182 2.03 1510 3065 11247 700 8323 2.10 1620 3402 11725 725 8469 2.18 1710 3728 12197 750 8620 2.25 1800 4050 12670 775 8771 2.33 1870 4357 13128 800 8916 2.40 1950 4680 13596 825 9072 2.48 2020 5010 14082 850 9224 2.55 2120 5406 14630 875 9377 2.63 2230 5865 15242 900 9462 2.70 2320 6264 15726 « continued next page- -12- TABLE VT continued: " D i s t r i b u t i o n of Energy Yearling C a t t l e " Intake of Body Weight Resting Metabolism Calories Gain (l)Ex- pected Pounds/ Day Net Cal- o r i c Con- tent of . Galn/pd. Gain/ Day i n Calories Net Cal - o r i c . In- take re- quired per Day 925 9600 2.78 2410 6700 16300 950 9798 2.85 2510 7154 16952 975 9946 2.93 2620 7677 17623 1000 10092 3.00 2700 8100 18192 (1) Assuming an instantaneous r e l a t i v e growth rate constant of,0.0030 (or 0.3 percent) throughout the body weight range 500 bo 1000 pounds. Reference to Table VT suggests that an 800 pound animal gaining 2.4 pounds per day requires 13,596 Calories of Net Energy per 24 hours. Accepting Morrison's figures given i n Table I I I f o r the Net Energy content of forages as 135 Calories per pound of green forage, i t would appear that the 800 pound animal c i t e d above w i l l be required to consume 100.1 pounds of green forage per diem to support t h i s rate of gain. In other terms 41.7 pounds of green forage should he required to produce 1 pound of body weight gain. This value i s not i n too great disagreement with the value of 43.4 pounds as c a l - culated using the National Research Council fs nutrient allow- ances. In f a c t the two values can probably be brought into closer agreement when one r e a l i z e s that the d a i l y rate of gain of 2.2 pounds as estimated by the National Research Council i s a mean rate of gain over the weight range 600 to 1000 poundsa The actual rate of gain at 800 pounds probably i s i n the neighborhood of 3»4 pounds per day* Support f o r t h i s con- tention can be found i n M i l l ' s work i n which the Mean Instan- taneous percentage growth rate f o r y e a r l i n g steers was found to be 0*3 percent* The previous calculations can best be summarized i n tabular form* Table VII presents such a .summary. TABLE VII: "SUMMARY OP NATIONAL RESEARCH COUNCIL AND ENERGETIC METHODS OP CALCULATING FORAGE REQUIREMENTS •** Body N. R. C. CALCULATIONS ENERGETIC CALCULATIONS Weight , . REQUIRED PER POUND OF GAIN REQUIRED PER POUND OF GAIN T.D.N, GREEN FORAGE DRY MATTER NET ENERGY GREEN DRY MATTER , - CALORIES FORAGE . 600 5,22 34.1 7.84 5593 41,4 s 9.51 700 6,14 40,1 9.22 5583 41.3 9,49 800 6,64 43,4 9,98 5665 41,9 9.62 900 7,04 46,1 10.60 5824 43,1 9.91 1000 7,73 50,5 11,61 6064 44,9 10.32 Sylvestre and Williams (1952) have proposed a method by means of which the d i g e s t i b l e nutrient production of f o r - age can be computed from the gain made by animals consuming such forage* In essence they have selected Morrison's feeding standard f o r growth and fattening and deducted from i t the estimated maintenance requirement as proposed by Armsby. The difference between these two estimates they take to be that portion of the d i g e s t i b l e nutrient intake which was u t i l i z e d f o r weight gain by the animal* Their calculations may be summarized i n part as shown by Table VIII• TABLE VIII: "ESTIMATED T.D.N* REQUIREMENTS FOR MAINTENANCE,.AND._PR0DUCTION,TIN.BEEF CATTIE" Live Weight Maintenance " Gain .Range Tot a l Digestible T o t a l D i g e s t i b l e Pounds Nutrients /100 l b s . Nutrients per )L Live Weight 1 Pound Gain 600 .775 2*11 650 .754 2.32 700 •732 2«52 750 .710 2.72 800 .697 2.92 850 .684 3.12 900 .671 3.32 950 .658 3,53 1000 •646 3.73 To i l l u s t r a t e the use of Sylvestre and William's -16- method of c a l c u l a t i o n , assume that a given animal weighing 800 pounds gains 50 pounds i n a period of 20 days. Then from Table VIII the animal w i l l require f o r maintenance 113.8 pounds of t o t a l d i g estible n u t r i e n t s . For body weight gain the same animal w i l l require 151.0 pounds of t o t a l d i g e s t i b l e nutrients, y i e l d - ing a t o t a l d i g e s t i b l e nutrient intake of 264 pounds over a period of 20 days or 13.2 pounds of t o t a l d i g e s t i b l e nutrients per day. Using grazing animals weighing 800 pounds and gaining at the rate of 2.5 pounds per day, each pound of weight gain must represent the consumption of 5.24 pounds of d i g e s t i b l e n u t r i e n t s . It i s evident that the product of weight gained and 5.24 represents the t o t a l forage digestible nutrients produced by the area of land on which the animals are grazing. To summarize, using National Research recommendations, the production of one pound of gain by an 800 pounds animal represents the consumption of 6.64 pounds of t o t a l d i g estible nutrients, and i f the animal made t h i s gain on pasture forage then the pasture must have yielded the 6.64 pounds of t o t a l d i g e s t i b l e nutrients i f no supplementary feeding had been carr i e d out. In the case of the energetic c a l c u l a t i o n s , one pound of weight gain represents the consumption of 5665 Galories i n the net sense. I f i t i s assumed that the r a t i o of digest- ib l e energy to net energy i s as 3.2 i s to 2.2, then the digest- ible energy consumption must be 8240 Calories of digestible energy. This would then represent 5.09 pounds of t o t a l digest- i b l e nutrients i f i t be assumed that 1616 Calories of d i g e s t i b l e energy i s obtained from one pound of t o t a l d i g e s t i b l e n utrients. -17* These values, 6.64 (National Research Council), 5.24 (Sylvestre and Williams), 5.09 (Energetic) Indicate that there w i l l he some variation i n digestihle nutrient yield dependent upon the method of calculation used. It does seem safe to conclude however that a not unreasonable estimate of productive capacity of pastures can be obtained using any one of the three methods. Various other methods of reporting productivity of pastures have been developed. Clipping methods, whereby the yields are expressed as pounds of dry matter per acre have been reviewed by Algren (1947). He emphasizes the advantages of using grazing animals. The four generally accepted methods involve the reporting of production i n the form of Animal Unit Months, Standard Cow Days, Standard Steer Days or pounds of production per acre. Burlingame (1949) reports live weight gains of lambs and steers i n the form of Animal Unit Months. An Animal Unit Month being the total digestible nutrients re- quired for a mature cow to produce 200 pounds of butterfat per year. This is taken to be equal to 400 pounds of total digest- ible nutrients. Bateman and Packer (1945), Rich,et al.,(1950. ) report pasture production in terms of Standard Cow Days which is taken to he represented by 16 pounds of total digestible nutrients per day* Other workers too numerous to mention use as a reference point the Standard Steer Day which is taken to be represented by 12 pounds of total digestible nutrients per day. Bartels (1944A) reports young sheep production In terms -18- of pounds of lamb par acre which i s arriv e d at by d i v i d i n g the t o t a l gain by the number of acres grazed. The use of the terms, Animal Unit Month (A.U.M.) , Standard Cow Day (S.C.D.) or gain per acre i n reporting gains i n animals have a number of Inherent e r r o r s . The reference points f o r the terms, Animal Unit Month i s estimated to be 400 pounds*of-tqtal d i g e s t i b l e nutrients f o r a mature cow givin g 200 pounds of bu t t e r f a t per year* Standard Cow Day i s taken to be equal to 16 pounds of t o t a l d i g e s t i b l e nutrients per day, and a Standard Steer Day (S.S.D.) i s taken to be equal to 12 pounds of t o t a l d i g e s t i b l e nutrients per day* These reference points are the product of the number of pasture days and the average number of stock carried on the pasture* The main disadvantages of the "Animal Day" method of reporting pasture productions are l i s t e d by Howstad (1953): "(a) No allowance can be made f o r gain or loss i n weight. (b) High producing animals are not distinguished from those having lower nutrient requirements because of lower production. (c) No allowance i s made f o r supplementary feeding. t t A further disadvantage i s that the nutrient requirements of animals vary according to the nature of the gain they are making. Steers weighing 500 pounds require less t o t a l d i g e s t i b l e nutrients per pound of gain than 950 pound steers because they are making t h e i r gain i n the form of muscle or protein rather than fat« The extreme case of t h i s i s i l l u s t r a t e d by Williams and Wood (1952) i n the following Chart. § pound water / 635 Cal« MAINTENANCE / \ pound protein ories v /*" 1 Pound PEED * 1 pound —* MUSCLE cone. ^ gain as GROWTH ^ PAT 1/10 pound water 3800 Cal- o r i e s 9/10 pound f a t 6 pound cone* They point out that such absolute d i s t r i b u t i o n of gain to muscle and fat never occurs. The actual case w i l l f a l l between the two extremes. Table V i l l u s t r a t e s the change i n composition of gain i n actual cases. The r e l a t i v e amount of .total d i g e s t i b l e nutrients required to produce one pound of gain as compared to one pound of four percent milk w i l l also a f f e c t the accuracy of r e s u l t s reported as Animal Unit Months or Standard Cow Days* Forbes et a l (1928, 1930, 1932, 1938) found ?the r e l a t i v e value of feed energy f o r maintenance, milk production and body i n - crease to be 1.000, 0.985, and 0.761 resp e c t i v e l y . This c a l - culation would indicate that 0.341 pounds of t o t a l d i g e s t i b l e nutrients which w i l l produce one pound of four percent milk with an energy value of 336 Calories would produce only 200 Calories -20- when used to Increase body weight. I t would require 10.36 times as much t o t a l d i g e s t i b l e nutrients to produce a pound of gain i n body weight as would be required to produce one pound of four percent milk. Therefore,the weight gain of animals as well as the production must be accurately measured to obtain a true produc- t i o n figure for the pasture. The reader Is referred to Report (1952) and Nowstad (1953) f o r a more d e t a i l e d study of these methods of reporting pasture production. The foregoing discussion would indicate that there are several methods at present i n use to assess pasture prod- uction. For purposes of comparison these methods are summar- ized b r i e f l y In Table IX. «21- T A B L E IX: "SUMMARY OP METHODS USED TO MEASURE . , PASTURE. PRODUCTION" M E T H O D W O R K E R S Units Per Pound of Gain National Research Council Committee o n Animal N u t r i t i o n T o t a l Digestible Nutrients Necessary per Pound of Gain Energetics Brody Haeker Armsby and others Energy Expressed as Calories Required to Produce a Pound of Gain Maintenance Sylvestre T o t a l D i g e s t i b l e plus Williams Nutrients Required Gain — * to maintain a given weight and produce a given gain Standard Cow Bateman, Packer, 16 Pounds of To t a l Rich and Digestible Nutrients ' Days ~ others taken as requirements of one Standard Cow Standard Numerous 12 pounds of t o t a l Steer d i g e s t i b l e Day Workers nutrients taken as requirements of one standard Steer, Animal Burlingame 400 pounds of t o t a l Unit and d i g e s t i b l e nutrients Month Others taken as requirements f o r ene mature cow to produce 200 pounds of butterfat per year -22- III. E X P E R I M E N T A L A. EXPERIMENTAL ANIMALS. The animals used to graze the Irrigated pastures •were loaned for the purpose. The pasture production was such that eighteen yearling Holstein steers had to be used during the last thirty days of grazing. Alt other animals used were of predominantly Hereford breeding. Since the steers had to be re- turned to the owner at a body weight of 1000 pounds, a continuous removal and replacement of animals took place throughout the graz- ing season. In general, the type of animals available for this test left muoh to be desired. The animals were extremely variable with respect to weight and age. The fi r s t thirty-eight animals obtained ranged in age from eighteen months to thirty months. The range in weight was from 600 to 900 pounds with an average weight of 843 pounds. Prom previous calculations such animals would re- quire 5.09 to 6.64 pounds of total digestible nutrients per day to produce one pound of body weight gain. A number of the first steers obtained were ex- tremely nervous in temperament and required a longer period of acclimatization before they settled down in the confined space of the irrigated pastures. B. ANIMAL PROCEDURE. The animals were weighed on a Fairbanks MorBe platform scale equipped with a fully enclosed box. See Photo- graph, Appendix VI. The increment of weight on such a scale -23- i s two pounds. The r e p e a t a b i l i t y of weight on a scale of this type Is shown i n Table X. To obtain t h i s r e p e a t a b i l i t y , ten steers were weighed ten i n d i v i d u a l times i n succession. The scale was balanced following each weighing, T A B L E X wRepeatabiIity"of Scale Used In Weighing Experimental_Animals 0 Weights Average of V a r i a t i o n Range Obtained Ten Weights from In Obtained ' Average Weights • 1) 8266 4 6,2 2) 82 68 8.2 3) 8266 6.2 4) 8262 4 2.2 5 j 8260 8259,8 + 0,2 6J 8256 3,8 7) 8256 - 3.8 8) 8258 1.8 9^ 8254 5.8 10) 8252 7.8 The error i n weighing based on a group weighing and average weight of fee ten weighings would be 0.19 percent * Such an error i s n e g l i g i b l e on a group basis but I f such an e r r o r was committed f o r the i n d i v i d u a l weighing i t would amount to 1,9 percent of the animal's weight and th i s would be an appreciable e r r o r , A s i m i l a r r e p e a t a b i l i t y test -24- using one animal was performed and the range i n weights was found to be s i x pounds on an animal averaging 852«8 pounds over ten weighings* This represents an error of 0.70 percent of the animal's body weight* Such an e r r o r would appear to be n e g l i g i b l e and may well be accounted f o r by the defecation of the animal while being ..'too-v̂ u on and off the scale* The experimental animals were weighed i n groups of ten animals to obtain a group weight. The scale was balanced a f t e r weighing each group to correct f o r manure accumulation on the platform during weighing* One weight was taken as the i n i t i a l weight a f t e r the animals had been i n dry l o t feeding f o r twenty-four hours on f u l l feed* Subsequent weighings were ob- tained when fee animals went into and came out of each pasture* In actual practice t h i s allowed the c o l l e c t i o n of a group weight every four to f i v e days, as grazing time on each pasture amount- ed to four or f i v e days. (See Appendix I I I ) * Care was taken to weigh the animals at the same time of day so that the degree of f i l l would be approximately the same* In addition, an attempt was made to leave the same amount of aftermath i n each pasture as t h i s f a c t o r has an effect on degree of f i l l * The Importance of allowing f o r degree of f i l l has been f u l l y disbussed by RItzman and Benedict (1938) and Taylor (1953)* C. PASTURE FORAGE ASSESSMENT PROCEDURE. " ' : : Dry "matter"content; of the pasture forage as well as t o t a l dry matter production was determined from c l i p p l o t s * -25 Eight mower strips, 32 Inches by 40 feet were cut immediately before the animals went on pasture. These strips were located at random over the whole pasture area. The forage cut from each mower strip was weighed Individually. A two pound sample from each strip was oven dried at 200 degrees Fahrenheit for forty- eight hours. The average dry matter content of the eight samples was then taken to represent the dry matter content of the forage for that pasture. Protein content of the pasture was determined on a representative sample from every eight pasture d i p s . The pro- cedure used was that of the Association of Official Agricultural Chemists (1950). The establishment and management of the pastures is discussed fully elsewhere in the text, see Appendix II and III. Animal disease factors and abnormal physiological conditions encountered are discussed in Appendix V. 17. RESULTSi A. ANIMALS; Table XI presents a summary of a l l weight data obtained on the experimental steers. see over. T A B L E XI: "SUMMARY OP ANIMAL WEIGHT DATA1 Experimental Period 1 2 3 4 5 6 7 8 9 10 11 MEAN Number of Pasture Days 8 6 28 3 5 33 6 7 1 2 20 30 148 Number of Animal Days 304 240 1512 165 190 1320 276 315 92 520 1200 6134 Actual Number Animals S t a r t i n g 38 40 54 53 38 40 46 45 46 51 40 44.6 Actual Number Animals F i n i s h - ing T o t a l I n i t i a l Weight 38 40 54 53 38 40 46 45 46 51 40 44.6 32040 34784 46452 49286 33784 36310 43408 42866 44096 47422 36536 40,634.9 Total F i n a l Weight 33524 35192 50240 49408 34435 38248 43776 43192 44548 48772 38560 41,808.6 Average I n i t i a l Weight 843.1 869.6 860.2 929.9 889.0 907.7 943.6 952.5 958.6 929.8 913.4 908.8 Average F i n a l Weight 882.4 894.8 922.9 932.2 906.1 956.2 951.6 959.8 968.4 956.3 964.0 935.8 Average Weight During Period 862.7 882.2 891.5 931.0 897.5 931.6 947.6 956.1 963.5 943.0 938.7 To t a l Gain per Lot 1484 408 3788 122 651 1938 368 326 452 1350 2924 12911 Average Daily Gain per Head 5.2 4.2 2.5 .73 3.4 1.4 1.3 1.1 4.9 2.6 1.6 2.6 -27- B. PLANT DATA Table X T T presents a summary of the data collected and cal- culated on the pasture forage. Using the information embodied in Tables VII, VIII, IX and XII, i t i s possible to arrive at an estimated production figure for the pastures. This information i s presented in summary form in Table XIII. The pasture period was 146 days. Calculated as per the method of Sylvestre and Williams, (Table VHI), the total production of total digestible nutrients on the pasture was 77,221.7 pounds. Represented on a per acre basis, this amounts to 4290.0 pounds of total digestible nutrients per acre. Cal- culated as per the standard of the National Research Council (Table VII), the total production was 89,612.6 pounds of total digestible nutrients or 4978.4 pounds of total digestible nutrients per acre. Similar cal- culations by energetic methods (Table IX) give a net Caloric figure of 145,784,874 Calories. Assuming 1616 Calories per pound of total digestible nutrients, this represents a total production of 90,213.4 pounds of total digestible nutrients or 5011.8 pounds of total digest- ible nutrients per acre. The protein percentages expressed in Taftle XII would indicate the high crude protein content of pasture forage. The percent crude protein i s based on nitrogen x 6.25 since this i s the generally accepted figure for calculating the protein content of feedstuffs. The average crude protein percentage for the season was 25.71 percent -28- vith one pasture going as high as 34 percent during the season* There did not appear to be a relationship between the application of nitrogen fertilizer and the protein content of the forage* One hundred pounds of ammonium nitrate per acre was applied to the following pastures on the dates listed* Pasture Number 5: July 3 1952 Pasture Number 4: July 3 1952 Pasture Number 3: July 10 1952 Pasture Number 2: July 16 1952 If high crude protein content of the forage had been encountered on clips immediately following the application of ammonium nitrate, i t would have indicated a large proportion of nitrate nitrogen to be present* The clipping dates as recorded in Table XII show that this did not occur* TABLE X I I : "SUMMARY OP PLANT DATA ON PASTURE FORAGE" PASTURE C l i p - ping Date Aver- age Pds. Green Fo rage Per acre Aver- age Dry Matter Per Acre Per- cent Dry Mat- t e r Per-c cent Protein 6.25XN C l i p - ping Date Aver- age Pds. Green Forage per acre Aver- age Dry Matter per acre Per- cent Dry Mattel Per- cent Pro- t e i n 6.25XN C l i p - ping Date Aver- age Pds. Green Forage Per acre Aver- age Dry Matter Per acre Per- cent Dry Matter Percent Protein 6.25XN May 31 7921.8 1915.7 24.1 19.61 May 26 7942.3 1674.3 21.9 28.64 May 20 5035.6 1162.2 24.0 14.37 June 24 3111.4 954.4 26.4 27.11 June19 3746.0 980.8 26.2 18.74 Jun 16 1965.1 556.9 28.6 24.96 July 14 3745.9 768.8 20.3 31.53 J u l 9 5567.8 982.5 17.6 34.05 J u l 5 1924.2 373.3 19.4 32.90 Aug,18 11667.9 2558.8 22.3 20.05 A u g l l 12015.9 2366.2 19.8 29.94 Aug 1 5997.7 1336.8 22.2 30.01 Sep.10 1330.5 364.1 27.6 24.30 Sep 6 3213.7 795.8 24.7 24.20 Sep 3 2702.0 567.6 31.0 31.84 Sep.29 1658.0 350.1 21.1 28.45 Sep 24 2845.3 569.1 20.0 24.20 Sep20 1248.6 334 .0 27.2 19.50 Total 29,434 .3 6911.6 Total 35,331.0 7368.7 Total 18,873.2 4331.0 Ave rage 25.17 Average 26.62 Average 25.59 Range 11.92 Range 15.31 Range 18.53 T --continued next page—- TABLE X I I . continued. ŜUMMARY OF PLANT DATA ON PASTURE FORAGE1* P A S T U R E #4 P A S T U R E # 5 Clipping Date Ave rage Pounds Green Forage per acre Average Dry Matter per acre Peroent Dry Matter Peroent Protein 6.25XN Clipping Date Average Pounds Green Forage per acre Average Dry Matter per acre Percent Dry Matter Percent Protein 6.25XN May 14 5997.7 1346.0 22.5 32.05 June 11 6468.5 1499.9 23.4 20.70 June 5 10,899.0 2436.2 22.5 23.85 July 2 3316.1 716.3 21.6 34.47 June 28 1801. 3 344.1 19.2 20.49 July 26 7778.6 1775.0 22.8 20.59 July 19 5997.7 1191.4 19.7 22.23 Aug 29 3131.9 752.3 23.9 26.08 Aug. 25 8167.5 1983.6 24.7 30.37 Sept.18 3152.4 354.3 22 .3 33.73 Sept .15 1637.6 503.7 32.5 19.50 Total 29,945.2 6443.8 Total 28,494.1 6486.0 Avo rage 27.93 Average 23.28 Range 13.88 Range 10.87 AVERAGE YIELD OF DRY MATTER FOR THE FIVE PASTURES: 6308.3 POUNDS DRY MATTER PER ACRE TOTAL YIELD FOR 18 ACRES: 113,549.4 POUNDS OF DRY MATTER OVER ALL PERCENT PROTEIN: 25.71 PERCENT. -31 TABLE XIII: "SUMMARY OP PASTURE PRODUCTION CALCULATED . . BY VARIOUS METHODS" Experi- Sylvestre National mantal and Research Energetics Period Williams Council 1 Pounds 6393.2 Pounds 10,239.6 Calorie e 16,887,920 2 2770.5 2,835.6 4,708,320 3 21,496.9 26,516.0 43, 940,800 4 1437.1 884.5 1,467,660 5 3282.3 4589.5 7,593,915 6 14,893.1 14,050.5 22,227,240 7 2,982.6 2,712.1 4,393,280 8 3,103.7 2,428.7 4,009,800 9 2,175.1 3,376.4 5,591,240 10 7,937.5 9,922.5 16,457,500 11 14,464.7 14,775.2 24,510,640 To t a l 80,936.7 93,327.6 151,788,315 Less T.D.N. Fed (1) 3,715.0 3,715.0 6,003,440 77, 221.7 89,612.6 145,784,875 (1) 7430 pounds of good q u a l i t y oat hay was fed during the l a s t period.As per Morrison's recommendations, t h i s was taken to have a digest- i b i l i t y of 50 percent, (2) The 3715 pounds of t o t a l d i g e s t i b l e nutrients derived from hay was taken to have a C a l o r i c content of 1616 Calories per pound. -32- V. D I S C U S S I O H The production data presented i n Table XIII tends to bear out conclusions expressed i n Section I I I . The Nation- a l Research Council method and the energetic method of estimating pasture production would appear to be comparable, there being only a 600.8 pound difference i n the two calculated amounts of t o t a l d i g e s t i b l e nutrients* This represents a difference of .66 percent between the two methods. The method of Sylvestre and Williams appears to he app B e d ably below that of the other two and here the difference i s approximately t h i r t e e n percent between t h e i r method and the other two* The only figure against which these calculations can be checked i s that of the forage production data presented i n Table XII. From these data the calculated t o t a l production of dry matter was 113, 549,4 pounds. Using the recommendations embodied i n Report (1952) i n which an average d i g e s t i b i l i t y of 72 percent f o r pasture forage i s suggested, the dry matter production would represent 81,755 pounds of t o t a l d i g e s t i b l e nutrients * In t h i s case the method of Sylvestre and Williams i s approximately 5 percent below that of the dry matter c a l - c u l a t i o n while the National Research Council and energetic methods are approximately 10 pereent above that of the dry matter calculations* This i s not an uncommon occurrence when comparing c l i p plot data with grazing animal data* The reasons f o r t h i s have been investigated by numerous workers and have been summarized i n Report (1952) as follows: "'When the herbage -33- i s upstanding more herbage i s out by c l i p p i n g techniques than i s procured by animals when grazing,, (2) When the herbage i s procumbent, such as with White Dutch clover, the animals can graze more forage than can be obtained by c l i p methods* (3) Animals s o i l and trample a c e r t a i n amount of forage which i s not eaten. (4) When mower s t r i p methods are used no account can be made for forage growth during the days the animals are on the pasture." The foregoing differences i n the methods of estim- ating pasture production point up the need f o r accurate data* For example during period One, the animals produced an average d a i l y gain of 5*2 pounds per day* Such a gain would Indicate that an error due to weighing increase i n degree of f i l l has been committed* When we consider that f i l l i n an animal can account f o r up to 31 percent of Its l i v e body weight* (Ritzman and Benedict 1938))the importance of such a f a c t o r i s apparent* That such a d a i l y gain i s improbable can be seen by the fact that an animal weighing 862 pounds would have to consume 35*88 pounds of t o t a l d i g e s t i b l e nutrients per day to produce 5*2 pounds of body weight gain. This represents an Intake of 235 pounds of green forage or an intake of 54*05 pounds of dry matter per day. The capacity of an 862 pound animal would not allow such forage consumption. On the animal side of estimating forage production -34- i t would appear that accuracy could be increased by more frequent individual weighings* An individual weight taken at weekly intervals would allow the regression of weight against time and hence permit a much more accurate estimate of the total digestible nutrients or Caloric intake necessary to produce a given gain* In conjunction with / the frequent individual weighings of the animals, digestibility trials and complete chemical analysis of the forage would aid in increasing the accuracy of estimating pasture production* The use of individual weights would also allow for accurate graphic presentation of weight gain data* Such graphic presentation would allow for an assessment of the type of gain being laid on by each animal. An example of this type of graphic present- ation i s shown in Graph I (which i s taken from Williams and Wood (1952)). see over. looo. 9ooi 8 0 0 7oot 60O1 1 to 1 5oo BULL NO-1 CO o 4 0 0 1 T 270 360 400 W 750 835" g 1 3oo 2oo 162 180 198 216 234 252 270 288 306 324 AGE QF ANIMAL IN DAYS 342 360 378 396 414 432 450 468 -35- An int e r e s t i n g aspect a r i s i n g out of the chem- i c a l analysis of the forage samples f o r protein i s that there i s an excess of available nitrogen to the animals* Therefore there must be a high excretion of nitrogen i n the feces and urine. This i s one of the reasons why extreme clumping occurs on i r r i g a t e d pastures around droppings. This high excretion points up the need f o r good management of pastures so that the droppings w i l l be adequately spread to reduce t h i s clumping. Very l i t t l e trouble i s experienced from urine spots since the I r r i g a t i o n water acts as a di l u e n t . To I l l u s t r a t e the above case of nitrogen excre- t i o n , the following t h e o r e t i c a l case Is set up: an 800 pound steer consuming 100 pounds of pasture forage per day which contains 20 percent dry matter and 25 percent protein w i l l con- sum© f i v e pounds of crude protein. Crampton (1939) l i s t s the d i g e s t i b i l i t y of the crude protein of mixed dried pasture grass aa 75 percent, there- fore t h i s steer would consume 3.7 pounds of di g e s t i b l e crude protein (D.C.P.) per day. Brody (1945) indicates that an 800 pound steer requires .4 pounds of digestible crude protein (D.C.P.) f o r maintenance. I f t h i s steer made a gain of 3 pounds per day and the assumption i s made that t h i s gain Is t o t a l l y protein the steer would need .8 pounds of pro t e i n , assuming protein gain as being 75 percent water. The following relationship e x i s t s : Digestible crude protein consumed: 3.7 pounds -36- Digestible Crude Protein required for Maintenance •4 pounds Digestible Crude protein required for gain •8 pounds Excess digestible crude protein 2*5 pounds Therefore 2*5 pounds of Digestible crude protein are returned to the pasture per day in the degraded form with the feces and urine* Converted back to nitrogen* assuming protein is nitrogen x 6*25, this would equal *4 pounds of nitrogen excreted per day by the steer* 6308*3 pounds* The average protein percent for the season was 25*71 as shown in Table XII* Therefore 1621*8 pounds of crude protein was produced per acre* Converted to nitrogen this would equal 259*4 pounds of nitrogen* The above facts point up the need for heavy fertilization of irrigated pastures because a depletion of nitrogen reserves would soon occur under such heavy production* In fact the growth response obtained by mid-summer and f a l l applic- ations of ammonium nitrate bear this out* Since there is an excess of protein produced in pasture forage, i t would be logical to assume that there may be a deficiency of energy. Foley (1933)* Harwood (1933), and Perkens (1935) have shown that in supplementary feeding i t i s energy that i s required* They came to the conclusion that low protein feeds were best suited for supplementary feeding* Table XII l i s t s the average dry matter yield per acre as -37- VI. SUMMARY AND CONCLUSIONS The various methods of estimating pasture production by use of animals have been investigated and discussed. The following conclusions can be drawn: 1) To obtain an accurate estimate of pasture production, using animls as the necessary device, the type of gain being made by the animal must be considered. Evidence from other work indicates that frequent weighing on an individual animal basis wil l assist materially in increasing the accuracy of the production estimates. In conjunction with these frequent individual weighings, digestibility trials and complete chemical analysis of the pasture forage should be undertaken. 2) The degree of " f i l l " in an animal can materially affect the weight recorded, therefore care should be taken to eliminate inaccuracies due to(this cause as much as possible. This may be done by weighing the animals at the same time of day at each weighing, 3) The Standard Steer Day, Standard Cow Day, Animal Unit month, and pounds of beef per acre are methods of assessing pasture forage but have a number of inherent errors and should be used with reservations. 4) The crude protein content of pasture forage is high and would indicate that there may be a deficiency of energy in pasture forage. -38- 5) The production of beef through the use of irrigated pastures is one means of intensifying beef production* 6) The production of total digestible nutrients from the experi- mental pastures under study was found to be from 4290*0 to 5011*8 pounds per acre in 148 pasture days depending upon the method used in calculating the production* A P P E N D I C E S The Appendices which follow are included with this Thesis because they form an essential background for the evolution of these f i r s t irrigated pastures* Since the present work must represent an exploration into, what for this area is a new field of investigation, much of what i s included in the following pages i s necessary to obtain a perspective of the entire field of Irrigated Pasture investigations* It i s regrettable that more detailed and recorded information i s not available in the Agronomic and economic aspects of Irrigated pasture production* «S9- A P P E N D I X I. IRRIGATED PASTURE BACKGROUND I. HISTORY: Irr i g a t e d pastures have been i n existence f o r years but the intense interest shown i n these pastures has been brought about i n l a t t e r years through a need to i n t e n s i f y forage production* Morgan (1949) points out that a f i v e acre planting In 1915 i n the Wuribee D i s t r i c t of V i c t o r i a , A u s t r a l i a was the beginning of a development which reached approximately one t h i r d m i l l i o n acres by 1947* The 1940 Census of I r r i g a t i o n i n the United States estimated that 2.7 m i l l i o n acres of i r r i g a t e d lands i n the seventeen western States are used f o r forage prod- uction f o r livestock* Anderson (1952) estimates that 150,000 acres of land are under I r r i g a t i o n i n B.C. Further estimates are made that an additional 500,000 acres could be brought under i r r i g a t i o n . (Farrow, 1949). It i s not to be presumed that a l l t h i s acreage i s or w i l l be used f o r i r r i g a t e d pastures but the acreage i s on the increase and i t i s l i k e l y that some land that Is at present i n tree f r u i t s , vegetable production or hay production w i l l be con- verted to i n t e n s i f i e d i r r i g a t e d pastures. Factors which con- tribute to t h i s change over are the development of new i r r i g a t e d lands, the need f o r more forage, the low labor cost of I r r i g a t i o n i n t h i s manner and the necessity of changing the type of a g r i - culture practiced i n areas that are marginal f o r c e r t a i n other . crops. M i l l e r (1951), reporting on the f i r s t improved i r r i g a t e d pasture i n Oregon,mentioned that 5000 acres of new see dings had taken place within three years of the e s t a b l i s h - ment of the f i r s t improved pasture. This pasture produced 600 pounds gain per acre at a cost of a l i t t l e over seven cents per pound of gain. 2. SOILS: S o i l s used f o r I r r i g a t e d pastures vary greatly as to physical and chemical c h a r a c t e r i s t i c s . Some of the s o i l s used are high i n f e r t i l i t y but there i s a tendency to use poorer classes of s o i l s . These s o i l s may be r e l a t i v e l y non-arable because of the presence of s a l t s , shallowness, presence of rocks or steepness of slopes, or other conditions. Most of the s o i l s used f o r Irrigated pastures are t y p i c a l of a r i d conditions. Thome (1948) characterizes these s o i l s as being low i n organic matter and containing adequate or ex- cessive quantities of calcium, sodium, magnesium, potassium, carbonates and sulphates. He also indicates that these s o i l s when put under i r r i g a t i o n often contain Inadequate amounts of phosphorus and nitrogen f o r maximum production. Under i r r i - gated pastures these s o i l s rapidly increase i n content of organic matter and nitrogen. Magiatad and Christiansen (1944) claim that a large part of the 20 m i l l i o n acres under i r r i g a t i o n i n the mine teen western states contain enough soluble s a l t s to depress crop, y i e l d s . 4 smaller area contains enough a l k a l i that crop production i s -41** greatly c u r t a i l e d and unprofitable* Richards (1947) has c l a s s i f i e d s o i l s into s a l i n e , s a l i n e - a l k a l i , and n o n - s a l i n e - a l k a l i s o i l s . The s a l i n e s o i l s are defined as s o i l " f o r which the conductivity of the satur- atio n extract i s greater than four millimhos per cm. (at 25oC) and the exchangeable (SP) sodium percentage i s less than 15. The pH of the saturated s o i l paste may exceed 8.5" • These s o i l s are characterized by white crusts on the surface or by streaks of s a l t i n the s o i l . They can be reclaimed by leaching and drainage. The s a l i n e - a l k a l i n e s o i l s are defined as " s o i l s f o r which the conductivity of the saturation extract i s greater than 4 millimhos per cm. (at 25°C) and the exchange- able sodium percentage i s greater than 15. The pH of the saturated s o i l paste may exceed 8.5% The n o n - s a l i n e - a l k a l i s o i l s are those " f o r which the exchangeable sodium percentage i s greater than f i f t e e n and the conductivity of the saturation extract i s less than 4 millimhos per cm. (at 25°C). The pH values f o r these s o i l s generally range between 8*5 and 10. The l a t t e r two types of s o i l are more d i f f i c u l t to reclaim because of the low rate of water penetration. Richards (1947) and Hamilton et al.(1945) indicate that the roots of s a l t tolerant forage plants increase permeability of s a l t y s o i l s and speed up rate at which s a l t s may be leached from them. Morgan (1947) considers land l e v e l l i n g e s s e n t i a l -42- to reclamation of salty land* L e v e l l i n g makes possible the uniform a p p l i c a t i o n of water to leach s a l t s downward* Richards (1947) has reported on the sa l t tolerance of a number of species. TableXIV(in Appendix I) summarizes h i s findings. T A B L E XIV "SALT TOLERANCE OP FORAGE CROPS ACCORDING TO RICHARDS (1947).° Tolerance decreases from top to bottom* S c i e n t i f i c names added by K e l l e r and Peterson (1950) GOOD SALT TOLERANCE A l k a l i sacaton Salt grass Nuttal a l k a l i grass Bermuda grass Rhodes grass Rescue grass Canada wild rye Beardless wild rye Western wheatgrass (Sporobolus ai r o i d e s ) ( D i s t i c h l i s spp.) (Pu c c l n e l l l a n u t t a l l i a n a ) (Cynodon dactylon) (Chloris gayana) (Bromus cat harticus) (Elymus canadensis) (Elymus t r i t l c o i d e s ) (Agropyron smithii) MODERATE SALT TOLERANCE White sweet clover Yellow sweet clover Perennial ryegrass Mountain brome Barley (hay) Birdsfoot t r e f o i l (Melllotus alba) (Melilotus o f f i c i n a l i s ) (Lolium perenne) (Bromus carinatus) (Hordeurn vulgare) (Lotus corniculatus) -43- TABLE XIV (continued) Moderate S a l t Tolerance Strawberry clover Dallas grass Sudan grass Hubam clover A l f a l f a T a l l fescue Rye (nay) Wheat (hay) Oats (hay) Orchard grass Blue grama Meadow fescue Reed's canary Big t r e f o i l Smooth brome T a l l (meadow) oat Cicer milk vetch Sour clover Sickle milk vetch POOR SALT TOLERANCE White (dutch) clover Meadow f o x t a i l Alsike clover Red clover Ladino clover Burne t (continued) (Trifolium fraguferum) (Paspalum dilatatum) (Sorghum vulgare sudanense) (Melilotus alba annua) (Medlcago sativa) (Festuca e l a t i o r arundinacea) (Secale cereale) (Tritlcum sativum aestivum) (Avena sativa) (Dactylis glomerata) (Bouteloua g r a c i l i s ) (Festuca e l a t i o r ) (Phalaris arundinacea) (Lotus uliglnosus) (Bromus lnermis) (Arrhenatherum elateus) (Astragalus c i c e r ) (Melilotus indlca) (Astragalus f a l c a t u s ) (Trifolium ripens) (Alopecurus pratensis) (Trifolium hybridum) (Trifolium pratense (Trifolium ripens latum) (Sanguisorba minor) -44- 3, PASTURE MIKTURES: K e l l e r and Peterson (1950) point out how d i f f i c u l t i t i s to conduct studies on pasture mixes because of the number of combinations* Only three grasses and three legumes give r i s e to forty-nine d i f f e r e n t mixtures containing one or more grasses with one or more legumes* Eight grasses and eight legumes pro- vide sixty-four mixtures of a single grass with a single legume, 784 mixtures of two grasses with three legumes and 4,900 mix- tures of four grasses with four legumes. There are a possible 65,025 d i f f e r e n t mixtures, using one to eight grasses with one to eight legumes, not including differences i n seeding rates. They also point out that most pasture mixture studies have i n - cluded selected species put i n combinations considered of most value by the experimenter* K e l l e r and Peterson (1950) mention that Sanborn (1894) and French (1902) recommended that Kentucky blue grass be not included i n pasture mixtures as i t i s r e l a t i v e l y unpro- ductive as a pasture grass* Welch (1914) recommended a mixture of Kentucky blue grass 8, Orbhard grass 5;̂  Smooth brome 5, Meadow fescue 4, Timothy 4, and White clover 2 pounds per acre. Later Welch (1917) pointed out that Orchard grass and Brome grass were the more important grasses, while Kentucky bluegrass, Meadow fescue and Timothy were of lesser importance. Current recommendations appear to exclude Kentucky bluegrass from pasture mixtures* Common white clover has been replaced lar<gej.y by Ladino clover and T a l l fescue i s included i n nearly a l l mixtures* -45- Hegnauer (1942) recommend*, the following mixtures f o r tho various s o i l conditions encountered i n western Washing- ton* For bottom lands, moist and f e r t i l e : I t a l i a n rye grass 4 pounds E n g l i s h rye grass 4 pounds Orchard grass 4 pounds Kentucky bluegrass 3 pounds Common white clover 2 pounds Red clover 2 pounds Alslke clover 4 pounds 23 pounds For upland s o i l s of clay loam or sand or sandy loam types: E n g l i s h rye grass 3 pounds I t a l i a n rye grass 3 pounds T a l l meadow oat grass 4 pounds Orchard grass 6 pounds Kentucky bluegrass 2 pounds Common white clover 1 pound Red clover 2 pounds Alaike clover 3 pounds 24 pounds He suggest*, that Chewing fescue could replace Kentucky bluegrass on bottom land* Law et al»(1945) recommends : the following mix- tures f o r i r r i g a t e d pastures i n Central Washington: (1) well drained* deep s o i l s , t hat can be i r r i g a t e d -46- unif ormly. (a) mixtures containing A l f a l f a A l f a l f a 5 pounds per acre Smooth brome 6 pounds per acre Orchard grass 4 pounds per acre T a l l oat grass 4 pounds per acre (b) Mixtures containing clover: Ladino clover 2 pounds per acre Smooth brome 6 pounds per acre Orchard grass 4 pounds per acre T a l l oat grass 4 pounds per acre (2) sub-irrigated or poorly drained s o i l s : Ladino clover 2 pounds per acre Meadow f o x t a i l 7 pounds per acre A l t a fescue 4 pounds per acre (3) Dry areas where water i s l i k e l y to be l i m i t e d i n amount: A l f a l f a 6 pounds per acre Crested wheat grass 4 pounds per acre Smooth brome 6 pounds per acre Rogers (1949) indicates the best mixture f o r i r r i g a t e d pastures i n Central Oregon i s Ladino clover 2, Smooth brome 5, Orchard grass 3, and A l t a fescue 2 pounds* Later information from Rogers Indicates that Smooth brome grass has been dropped from the mix as i t d i d not do well under i r r i g a t i o n * M i l l e r (1951) indicates that a f t e r planting com- -47- plex mixtures and t e s t i n g them, Oregon now i s : A l t a fescue Orchard grass Intermediate wheat or Smooth brome Ladino clover the recommended mix f o r Central 6 pounds per acre 4 pounds per acre 6 pounds per acre 1 - 2 pounds per acre Many problems surround the se l e c t i o n of the best pasture mixture. Further investigation i s needed to determine the pasture mix best suited f o r d i f f e r e n t s o i l types and clim- a t i c conditions. As an example, T a l l or A l t a fescue i s con- sidered unpalatable i n some areas of the U.S. and Cunningham (1948) reports i t i s poisonous to cattle i n New Zealand. 4. PREPARATION OF LAND FOR IRRIGATION The l i t e r a t u r e w i l l not be reviewed on this com- plex problem. The subject has been adequately covered by Ham- i l t o n et a l (1945); Jones and Brown (1949); Bartels and Mor- gan (1944) and Raynor (1941). Although numerous types of i r r i g a t i o n systems are used they can be c l a s s i f i e d as Sprinkle or Flood. In Flood i r r i g a t i o n , l e v e l l i n g of some type i s usually necessary. 5. SEED BED PREPARATION Hamilton et a l (1945) l i s t the requirements of a good seed bed as fine textured, f i r m , moist, f e r t i l e and free of weeds. These conditions can be obtained through various methods of t i l l a g e and management. -48- Jones and Brown (1949) i n C a l i f o r n i a , recommend an I r r i g a t i o n just p r i o r to seeding to s e t t l e f i l l s , f i rm the s o i l and provide sub-soil moisture. When spr i n k l e r i r r i g a t i o n i s used, post seeding I r r i g a t i o n i n small applications appears desirable • Time of seeding depends l a r g e l y upon cli m a t i c conditions of the area i n which the pasture i s situated* In areas where mild winters p r e v a i l , Jones and Brown (1949) recommend f a l l and early winter seedings. Post and T r e t s v i n (1939) and Hamilton et a l (1945) recommend f a l l seeding i f the land i s not weedy, the grain has not shattered, and adequate i r r i g a t i o n water can be applied* -49- A P P E N D I X I I . MANAGEMENT OF PASTURES: 1* Grazing Managemont: New stands should he managed to promote rapid development of the young seedlings. Prolonged close grazing when the pastures are wet Bhould be avoided. Bartels (1947) points out that heavy grazing of young pastures i s sometimes necessary to prevent perennial rye grass from smothering out slower growing white c l o v e r . K e l l e r and Peterson (1950) l i s t three objectives of grazing management: (a) to maintain the desired balance between species (b) to obtain continuous high production (c) to obtain u t i l i z a t i o n of the forage when i t i s most n u t r i t i o u s . They point out that most pasture species now recommended provide high production but must have periods of re growth. This i s provided by r o t a t i o n grazing. Rotation grazing consists of the use of two or preferably three or more pastures i n a r o t a t i o n . A f t e r grazing, each pasture i s i r r i g a t e d and allowed to recover. The animals return to the f i r s t pasture three to s i x or eight times i n one season. Important considerations i n a grazing rotation are: (1) Length between grazing periods. This must be adjusted so that the animals graze the pastures when the forage i s at i t s most n u t r i t i o u s stage. I f i t i s too young the stand w i l l be -50- weakened. I f i t i s over mature i t w i l l be r e l a t i v e l y unpal- atable* (2) Number of days grazing i n each pasture. This should be kept to a minimum so that the animals do not have the chance to graze s e l e c t i v e l y , (3) Number of sub-divisions i n the f i e l d . These must by necessity be kept to a minimum to allow f o r ease of i r r i - gation and to lower the cost of fencing, Hodgson et a l (1934) report 8,82 percent gain from rotation grazing over continuous grazing, Semple et a l (1934) indicates that i n studies at B e l t s v i l l e , Maryland, r o t a t i o n a l grazing increased production 10 percent over continuous grazing, K e l l e r and Peterson (1950) mention that Starke (1947) of South A f r i c a l i s t s f i v e reasons f o r rotation grazing of sheep: 1, less selective grazing 2, less fouling of forage 3, more regular i r r i g a t i o n 4, less i n t e r n a l parasite i n f e c t i o n 5, better quality and more palatable forage. ~51« A P P E N D I X I I I . ESTABLISHMENT OP EXPERIMENTAL PASTURES 1. Preparation of Land: The eighteen acres used i n t h i s pasture were native sod that was extremely rough with "Nigger Heads." The land was ploughed and allowed to rot down over the winter. In the early Spring the land was disced twice with a heavy offset d i s c and then harrowed with a chain harrow. To produce a firm seed bed the land was packed with a Cultipacker. Seed bed preparation i s one of the most important aspects i n establishing an I r r i g a t e d pasture. B u r l i s o n et a l (1936) say, "'More stands of pasture plants are l o s t because of poor seedbeds than from any other single cause. These plants need a moist, f i n e , compact and f e r t i l e seedbed. In f a c t a well prepared seedbed i s probably more e s s e n t i a l f o r them than f o r any other crop." Most other investigators have ar r i v e d at the conclusion that a well worked fi r m seedbed pays o f f i n dividends of greater germination, stronger stands and greater production. 2. Seeding Pastures The eighteen acres of pasture was divided into f i v e equal sized f i e l d s and seeded to f i v e d i f f e r e n t mixtures as follows: Pasture Number One Pounds per acre Brome grass 6 Orchard grass 4 A l t a fescue 2 (cont inued) »52 « A l f a l f a 4 pounds per acre Ladlno clover 1 pound per acre Pasture Number Two Pounds per acre Brome grass Orchard grass A l t a fescue Ladlno clover Pasture number Three Brome grass Orchard grass Meadow fescue A l f a l f a White clover Pasture Number Four Brome grass Orchard grass Meadow fescue White clover Pasture Number Five Brome grass Orchard grass Timothy grass A l f a l f a Red clover 6 4 6 2 Pounds pe r acre 6 4 2 4 1 Pounds per £cre 6 4 6 2 Pounds per ficre 5 4 3 4 2 -53- Seeding was accomplished using a grain d r i l l with grass seed attachment* The grass seeds were seeded through the grain box and the Legume seeds through the grass seed box. The d r i l l discs or shoes were set into the ground quite deeply but the tubes were removed from the shoes and allowed to dangle. In t h i s way the seed i s broadcast on top of the ground and then covered s l i g h t l y by the drag chains. To further cover the seed to the desirable depth, the seeded land was packed a f t e r seed- ing with a Culfeipacker. This method of seeding covered the seed to a depth of 1/4 to 1/2 inches. 3. F e r t i l i z a t i o n of Pastures Immediately before seeding,300 pounds of ammonium phosphate 11.48.0 per acre was spread on the land. This was put on p r i o r to the l a s t harrowing and then harrowed into t he surface of the land. An alternate f e r t i l i z e r and one recommended strong- l y i s super phosphate 0-20-0 at 600 pounds per acre. The reason 11.48.0 was used i n t h i s case was that the s o i l s showed a de- p l e t i o n of nitrogen and the nitrogen i n the 11.48.0 was thought to be advantageous f o r germination and growth of the young seed- l i n g s . F e r t i l i z a t i o n a f t e r seeding has taken the form of applications of ammonium n i t r a t e 33-0-0 at the rate of 100 pounds per acre when thought necessary. In practice t h i s i s usually found to be i n the l a s t week of June or the f i r s t week of July when growth tends to slow down, and again during the -54- f i r s t week of September. The i n i t i a l a p p l i c a t i o n of 600 pounds of Super Phosphate, or 250 pounds of ajnmonium phosphate i s recommended so that s u f f i c i e n t phosphate i s added to supply a r e a d i l y available source of that material* Most of tiie s o i l s found i n the dry b e l t of the I n t e r i o r of B.C. are d e f i c i e n t i n available phosphorus;. This i s brought about by the f a c t that these s o i l s are alkaline i n reaction* The pH of the s o i l s on the Range Station i s between 7*8 - 8.0. These s o i l s can be termed "white a l k a l i " s o i l s and contain r e l a t i v e l y large quantities of soluble s a l t s * These soluble s a l t s form a complex with phosphates through f i x a t i o n of the phosphate as insoluble s a l t s * thus a large quantity of phosphate must he applied to s a t i s f y t h i s complex before the plants can have a r e a d i l y available source of phosphate* I t i s considered that 600 pounds of super phosphate per acre every three years w i l l supply s u f f i c i e n t phosphate to s a t i s f y the complex and to supply a source of phos- phate that i s r e a d i l y available to the plants* 4. Grazing Rotation The eighteen acres of pasture was divided into f i v e equal sized areas of 3*6 acres each* Through t h i s d i v i s i o n i t was possible to practice a r o t a t i o n a l system of grazing* The pastures were stocked at such a rate tflosit the animals grazed the forage on each pasture i n four to f i v e days, thus giving a 20-25 day period between grazing on each i n d i v i d u a l pasture* This period allowed s u f f i c i e n t regrowth of the forage so that i t could -55- be grazed when at a height of 6-8 inches. The forage was grazed to a l e v e l of 2-3 inches. An aftermath of 2-3 inches i s thought advisable so that the forage w i l l make a quick recovery. This much aftermath gives enough leafage to allow photosynthesis to go on at a more or less constant r a t e . In other words, plant recovery i s not slowed by a lack of top growth. This rate of grazing promotes a strong vigorous stand. 5. Management of Pastures: Proper management of the pasture sward i s of extreme importance. In many cases pastures are not considered a crop and therefore are not managed properly. B u r l l s o n (1936) indicates that unproductive pastures usually result from poor s o i l conditions and poor management with management being the cause of most f a i l u r e s . He l i s t s over-grazing as a prime reason f o r low production and suggests that alternate grazing be used as i t produces more feed than continuous grazing. In managing the experimental pastures on the Range Stat i o n , the following practices are followed: (a) Animals are turned into graze when the forage i s 6-8 inches high and they are removed when the forage has been grazed to a height of 2 to 3 inches. (b) Clumping of the grasses i s prevented by frequent mowings and harrowings to spread the droppings. It would appear that t h i s operation should take place four to f i v e times during the grazing season to maintain an even award. -56- The maintenance of an even sward reduces selective grazing and thus assists in a greater utilization of the forage* c) The pastures were seeded on June 5th, 1951* Pasturing was started on August 6th, 1951* A very light grazing was permitted at this time to assist in control of weeds and to firm the top soil* To further control weeds, the pastures were clipped twice before grazing commenced* That weeds were effectively controlled by these measures i s established by the complete lack of weeds on the pasture during the grazing season of 1952* 6* Irrigation of Pastures; The amount of water necessary and the frequency of irrigation depends on the characteristics of the soil* The most important aspect of irrigation i s to keep the roots of the pasture plants supplied with readily available water at a l l times* Without this, rapid growth and high prod- uction cannot be maintained* Sprinkler irrigation i s the most versatile method of irrigation and eliminates the problem of irrigating each pasture immediately after being grazed* With flood irrigation the problem arises of keeping the water off pastures that are being grazed* It should be pointed out that sprinkler irrigation i s generally more expensive than flood irrigation and should not be used where flood irrigation i s available and efficient* Water requirements of the pasture under study have been 2*5 acre feet per season so far but this will vary depending upon climatic and soil conditions* The irrigation aspects require further study. A P P E N D I X . IV "ANIMAL DISEASES AND ABNORMAL PHYSIOLOGICAL CONDITIONS" le Bloat: Bloat can be a severe problem on i r r i g a t e d pasture• AJBimals should be cl o s e l y watched for the f i r s t day a f t e r being turned into an i r r i g a t e d pasture* Prompt treatment i s necessary once an animal shows signs of bloat* There are several recommended treatments to a l l e v i a t e b l o a t , none of them are completely s a t i s f a c t o r y but a l l of them w i l l reduce the bloat i n animals i f used early enough* Drenching of the animals with a pint of mineral o i l , or a cup of coal o i l i n a cup of milk appears to relieve bloat i n many cases. Injection of "Rumene", a commercial preparation, into the rumen of a bloated animal using a 3 inch, 16 gauge needle and 100 c.c. of the material has re l i e v e d several cases of bloat that the writer has encountered. The use of a Trocar and Canula i s a positive means of r e l i e v i n g bloat, but care must be taken that the instrument i s inserted i n the right area and t hat the instrument i s clean. The following practises w i l l a s s i s t i n preventing bl o a t . (a) Pasture forage should not contain more than 50 percent by weight of legumes* (b) Animals should be fed dry hay before being turned out on pasture* (c) Animals should be l e f t on the pasture at a l l times* The removal of the animals at night has a tendency to -<5S- increase bloat because they are too hungry when turned out the following morning* 2, Foot Rot: Foot Rot can become a problem on i r r i g a t e d pastures since under the conditions p r e v a i l i n g i t can spread quickly from infected animals to non-infected animals* During the pasture season of 1952, twelve animals showed t y p i c a l signs of Foot Bot* 411 these animals were successfully treated using a 100 c*c. subcutaneous i n j e c t i o n of a Su l f a drug prep- aration supplied by a l o c a l veterinarian, Although a l l these animals recovered within three days of commencement of tr e a t - ment* there was an appreciable loss of fl e s h i n g i n a l l the animals. 5, Parasites: No trouble has as yet been experienced with Parasites on i r r i g a t e d pastures but i t i s understandable that the con- ditions that p r e v a i l , - close confinement and continuous use, , lend themselves to creating t h i s problem and pasture managers should watch f o r signs of p a r a s i t i c i n f e c t i o n . ANIMALS ON IR2IG-ATED PASTURE - 6 0 ANIMALS ON IRRIGATED PASTURE. Notice Bright of forage i n foreground 4 pa»ture immediately a f t e r removal of animal* -62- Scale used to weigh the animals B I B L I O G R A P H Y 1* Ahlgren, H.L., 1947. J . Am, Soc, Agronomy 39, 240 - 259. 2. Anderson, W.J., 1952. Transactions of the 5th. B r i t i s h Columbia Natural Resources Conference. Feb. 27, 28, 29. 143 - 53. 3. Bartels, L.C. and""A. Morgan, 1944., J» Dept. Agr., . V i c t o r i a , A u s t r a l i a , 42,, 291 » 295.. 4. Bartels, L.C., 1944A.. J . Dept. Agr. V i c t o r i a , . A u s t r a l i a , 42,, 391 - 397. 5. Bartela, L.C., 1947. J . Dept. Agr., V i c t o r i a , . A u s t r a l i a , 45. 201 - 210, 6. Bateman, G.<̂ ., and J.E. Parker, 1945. . Farm Home S c i . , (Utah) 6, No, 2, 10 - 11, 7. Brody, Samuel. (1945) Bioenergetics and Growth. Reinhold Pub,..Corp, . N.Y. p.476. 8. Burlingame/'B.B. 1949. C a l i f o r n i a Agr, 3. , 13 - 14. . 9. Burlison, W.L., H.P. Rusk and J . J . Peeper. 1936 Pasture Improvement and Management. I l l i n o i s , Agr. Expt. State Circ'., 465, pp. 50. 10. Crampton, E.W. (1939) The Nutritive Value of Pasture Herbage, S c i e n t i f i c Agr., 19: 6. 11. Cunningham, I. J . , 1948. New Zealand J . Agr.. 77 519. . 12. Farrow, R.C., 1949. Transactions of the 2nd. B r i t i s h Columbia Natural Rasources Conference, p. 42 ~ 48. 13. Foley, R.C. (1933) The Proper Supplementary Return f o r Milking Cows on F e r t i l i z e d Pasture, J . Dairy S c i . , 16: 407. 14. Forbes, E.B., W.W. Braman, M. K r i s s , 1928. J , A g r i . Res, 37, 253, 40, 37 (1930); J. Nut, 5, 183, (1932) 15, 565,(1938) 15. French, H.T. 1902.' Idaho Agr. Expt, Sta., B u l l . 33, 87 - 107, 16. Haeker, T.L., 1920. Investigations i n Beef Production, Minnesota Agr. Expt. Sta. B u l l . 193. 17. Hamilton, J.G., G.F. Brown, H.E. Tower, and W. C o l l i n s J r . , 1945. U.S. Dept. Agr. Farmers B u l l . 1973, p.p. 30. 18. Hegnauer, L. 1942. Better Pastures - More Milk., State College of Wash., Ext. C i r . 42. pp.3, 19. Hodgson, R.E., M.S. Grander, J.C. Knott, and" E.V. E l l i n g t o n , 1934. Wash, Agr. Expt. Sta. B u l l . 294, 1 - 36. 20. Horwood, H.E., and G.W. Putman, High versus Low Protein gain with Pasture. Mich, (^uart...Bull. 16s 20, 21. K e l l e r W. and M.L. Peterson, 1950, Ir r i g a t e d Pastures, Advances in'Agronomy, 2: 351 - 381. 22. Law, A.G., H.P. Singleton, and I.M. Ingham, Irrigated Pastures f o r Central Washington, State College of Wash., Ext. B u l l , 319. 23. Magistad, 0 .C• and' J.E. "Christiansen, 1944, U.S. Dept. Agr, C i r c . 707, pp. 1-32, 24. McGillivray, W., 1949, Transactions of the 2nd, B r i t i s h Columbia Natural Resources Conference, p. 61 - 84, 25. M i l l e r , A . E . , 1951. The place of Irrigated Pasture and Range and Livestock Management., Proc, 3rd. Ann. Meeting, Nor-West Sec. Amer. Soc, Range Manmt. Baker, Ore., Nov. 1. 26. M i l l s , J.A., Studies i n Beef Cattle N u t r i t i o n . B.S.A. Degree Essay. U.B.C., Van. B.C. 27. Morgan, A*, 1947*" J, Dept. Agr., V i c t o r i a , A u s t r a l i a 45, 111- 115. 28. Morgan, A« 1949., J. Dept. Agr. V i c t o r i a , A u s t r a l i a , 47., .97- 105, 199-207, 241-247, 29. National Research Council, (1945) Recommended Nutrient Allowances f o r Beef C a t t l e , Wash, D.C, No, 4. 30. Nowstad, F.S., S.B. Williams, L„S. Donovan, S.N. Donaldson, R.R, Cairns, 1953, Review of Literature on Methods and Techniques Employed i n Pasture Research. Central Exp. Farm Mimeo,, 31. Perkens, A.E., Prop, of Protein needed i n grain mixture fed with pasture. Ohio Agr. Expt. Sta. B u l l . 548: 64. 32. Post, A.H., and J . 6 . Tretaoen, 1939. Montana Agr. Ext. Ser. B u l l . 174: 1-14. 33. Raynor, G.B., 1941. j . Dept. Agr. V i c t o r i a , A u s t r a l i a , 39: 314 - 318. 34. Report, 1943. j . Dairy S c i . 26, 353 - 369. 35. Report, 1952. Agron, J . , 44. 39 - 50. 36. R'ich, L.H., A.F. Bracken, W.R". Bennett, and G,T,.Baird, 1950.. Utah Agr.» Ext e B u l l . 188, 1-24. 37. Richards, L.A» Ed. 1947, Diagnosis and Improvement of Saline and,Alkali S o i l s . U.S. Regional S a l i n i t y Laboratory, Mimeo. pp. 1 - 157. 38. Ritzman, E.G. and Francis G, Benedict, 1938, N u t r i t i o n a l Physiology of the Adult Ruminant, garnegie Inst.of Wash, 39. Rogers, A»> 1949. You Can Have Your Home on the Range. The Ore. Farmer, Aug. 4. 40. Semple, A.T., H.N. V i n a l l , C.R. Ehlow,'and T.E. Woodward, 1934. U.S. Dept. Agr. Misc. Pub. 194 - 1-89 41. Sylvestre, P.E., and S.B. Williams, 1952. Methods of Measuring the Relative Productivity of Pasture Experiments with Livestock, Mimeo. Central Exp. Farm, Ottawa, Revised. 42. Taylor, J.C. 1953. The Behaviour of Bullocks under Two Systems of Management. Vol. 1, No. 2. A p r i l . 43. Thorne, D.W., 1948." U.S. Dept. Agr. Yearbook, pp. 141 - 143. Tribe, BJ3., and J.G. Gordon. The Critical Approach in Grazing Behaviour Studies. B. J . of An. B. Vol. No. 1. Williams, CM., and A.J. Wood, 1952. Beef Bull Research Project., Dept. of Extension. U.B.C. Wordrop, J.C. (1953) Studies in the Behaviour of Dairy COKTS at Pasture. British J. of An. Behaviour. Vol. 1, No. 1, Jan. -oOoOoOoOoOoOo-

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