Science, Faculty of
Zoology, Department of
DSpace
UBCV
O'Keefe, James John
Master of Arts - MA
University of British Columbia
Forty-five fawns, representative of races of Odocoileus hemionus columbianus, Odocoileus hemionus sitkensis, and Odocoileus hemionus hemionus were raised together under similar environmental conditions. The daily dry matter intake was recorded for all of the animals for periods of from eight to twelve weeks during the early phases of growth which preceded puberty. It was found that dry matter intake reflected the net energy demands of maintenance and growth. Dry matter intake was also influenced by plane of nutrition, composition and digestibility of the ration, and condition of the animal. Some subspecific differences in growth and nutritional efficiencies were observed. It was shown that dry matter intake during early phases of growth of subspecies of Odocoileus hemionus could be estimated if net energy requirements of the animals and the digestibility coefficient of the ration(s) were known. Knowledge of the pattern of growth in the animal is essential for accurate calculation of the net energy requirements.
DRY-MATTER INTAKE DURING EARLY PHASES OF GROWTH FOR SUBSPECIES OF DEER (ODOCOILEUS HEMIONUS) by JAMES JOHN O'KEEFE A.B., UNIVERSITY OF CALIFORNIA 19^4 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF • MASTER OF ARTS i n the DEPARTMENT OF ZOOLOGY We accept th i s thesis as conforming to the standard required from candidates for the degree of MASTER OF ARTS Members of the Department of Zoology THE UNIVERSITY OF BRITISH COLUMBIA September, 1957 In presenting t h i s thesis i n p a r t i a l fulfilment of the requirements fo r an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the Head of my Department or by his representative. It i s understood that copying or publication of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of ^-gp/o The University of B r i t i s h Columbia, Vancouver S, Canada. ABSTRACT Forty-five fawns, representative of races of Oddeolleus hemionus columbianus, Odocoileus hemionus s i t k e n s i s , and Odocoileus hemionus hemionus were raised together under s i m i l a r environmental conditions. The d a i l y dry matter intake was recorded for a l l of the animals f o r periods of from eight to twelve weeks during the ea r l y phases of growth which preceded puberty. I t was found that dry matter intake r e f l e c t e d the net energy demands of maintenance and growth. Dry matter intake was also influenced by plane of n u t r i t i o n , compo-s i t i o n and d i g e s t i b i l i t y of the r a t i o n , and condition of the animal. Some subspecific differences i n growth and n u t r i -t i o n a l e f f i c i e n c i e s were observed. I t was shown that dry matter Intake during early phases of growth of subspecies of Odocoileus hemionus could be estimated i f net energy requirements of the animals and the d i g e s t i b i l i t y c o e f f i c i e n t of the ration(s) were known. Knowledge of the pattern of growth i n the animal i s essen-t i a l f o r accurate c a l c u l a t i o n of the net energy require-ments. AGKNOWLEDGMENTS The author Is indebted to many individuals f o r as-sistance and guidance i n the compiling and presentation of t h i s t h e s i s : To Dr. I . McT. Cowan, Chairman of the Zoology De-partment, f o r providing the opportunity and f a c i l i t i e s to work on the Deer Research Project, and fo r his d i r e c t i o n and enthusiastic Interest i n a l l phases of the Project; To Dr. A. J . Wood, Professor i n the D i v i s i o n of Animal Science, f o r his i n s t r u c t i o n , c r i t i c i s m , and i n -s p i r a t i o n ; To Dr. W. D. K i t t s of the D i v i s i o n of Animal Science f o r many excellent suggestions and c r i t i c i s m s ; To Dr. Marjorle Nelson of the I n s t i t u t e of Experi-mental Biology, Berkeley, C a l i f o r n i a f o r correcting the manuscript and f o r valuable and timely assistance i n organ-i z i n g the material f o r proper presentation; To Mr. Leo Kansky, Manager of the University of B r i t i s h Columbia Research Farm #2 f o r h i s w i l l i n g coopera-t i o n and timely advice; To students and members of the Game Departments of B r i t i s h Columbia and C a l i f o r n i a , too numerous to l i s t here, f o r t h e i r cheerful help and cooperation. The author i s further indebted t o the B r i t i s h Columbia Game Department f o r f i n a n c i a l assistance during the summer of 1956. TABLE OF CONTENTS Page EXPERIMENTAL . . . . . . . . . . . . . . . . » . • • 1 1* Animals and Housing • • • • • • • • • • • • • 1 2. Rations and Planes of Nutrition • • • • • • • 1 3. Methods of Determining Digestibility • • • • • 4 a) Total Collection 4 b) Chroiaagen • • • • • • • • • • • • • • • 5 RESULTS . . . . . . . . . . . . . . . . . . . e • • 7 1. Environmental Factors • • • • • • • • • • • • 7 2. Mortality . . . . . . . . . . . . . . . . . . 7 3. Growth • • • • • • 8 4. Energy Contents of the Ration • • • • • • • • 11 a) Milk . . . . . . . . . . . . . . . . . 11 b) Pelleted ration 15-56 . . . . . . . . . 12 5. Digestibility . . . . . . . . . . . . . . . . 13 6. Dry-Matter Intake • • • • • • • • • • • • • • 14 DISCUSSION . . . . . . . . . . . . . . . . . . . . . 17 1. Significance of Growth In Dry-Matter Intake. • 17 2. Influence of Digestibility on Dry-Matter Intake 21 3. Dry-Matter Intake • • • • • • • • • • • • • • 26 4. Subspeciflc Differences In Growth and Nutritional Efficiencies • . . . . . . . . . 42 5. Experimental Results Applied to Field Conditions 47 SUMMARY AND CONCLUSIONS 56 BIBLIOGRAPHY . . . . . . . . . . . . . . • 60 APPENDICES/ j; 1. Growth Curves 2. Weight Records 3. Gross Energy of Fecal Samples 4. Constituents of Pelleted Ration 15-56 LIST OP TABLES Page 1. Mineral Supplement Added to Condensed Milk Ration 2 2. Proximate Composition of Experimental P e l l e t Ration 15-56 4 3. Proximate Composition of Experimental P e l l e t Rations l l | and 15 i|. if. Growth Constants for Deer of the 1952 Colony . . 9 5. Growth Constants for Deer of the 1956 Colony. . ••. 10 6. Comparison of the Constituents" and Caloric Values of Doe's Milk with that of Condensed Milk. . . 12 7. D i g e s t i b i l i t y C o e f f i c i e n t s of Milk. . 13 8 . Chromagen Analysis of D i g e s t i b i l i t y of Pe l l e t e d Ration 15-56 . . . . . . . . v ll|. 9. Average'Growth Gain f o r 81j.-Day Period During E a r l y Phases of Growth l 6 10. Body Weights of Animals on High Plane of N u t r i -t i o n , February, 1957 20 11a C a l o r i c Intake, Resting Metabolism, and C a l o r i c Storage i n Males on High Plane of N u t r i t i o n . . 28 l i b C a l o r i c Intake, Resting Metabolism, and C a l o r i c Storage i n Females on High Plane of N u t r i t i o n . 30 11c C a l o r i c Intake, Resting Metabolism, and Calo r i c Storage i n Males on Low Plane of N u t r i t i o n . . 32 l i d C a l o r i c Intake, Resting Metabolism, and C a l o r i c Storage i n Females on Low Plane of N u t r i t i o n . 3^ 12. E f f i c i e n c y of Gain I4.3 13. Average Net Calories Consumed Per Pound of Gain . if4 Page lij.. Approximate Number of Weeks i n Pre-Weaning Period, lj.5 15. Percentage of Milk Calories i n Total Net Cal o r i c Consumption . . 45 16. Total Estimated Caloric Output and Storage of 1952 Colony Vancouver Island Deer f o r 8ij. Day Period Following P a r t u r i t i o n , ; . . ij.6 17. Net Energy Requirements f o r Twelve Week "Period Following P a r t u r i t i o n I4.8 18. Dry-Matter Intake f o r Twelve Week Period Follow-ing P a r t u r i t i o n 5>0 19. D i g e s t i b i l i t y Coefficients of Certain Forage Species on C a l i f o r n i a Deer Ranges 53 20. D i g e s t i b i l i t y C o e f f i c i e n t s of Certain Forage Species on Eastern White-Tail Deer Ranges . . . 54 INTRODUCTION Es s e n t i a l to the study of the l i f e h i s t o r y of a species i s a detailed knowledge of the animal's growth. The s i g n i f i -cance of ea r l y growth upon the ultimate s i z e and development of the mature animal has been w e l l established. In order to achieve even minimal rates of growth an animal must have a food source which contains the ess e n t i a l nutrients i n proper balance and which supplies the energy necessary f o r maintenance and growth. Dry-matter intake i s i n large part a r e f l e c t i o n of the net energy demands of the animal. I t was the objective of t h i s thesis to determine f o r the mule deer (Odocoileus hemionus hemionus Raflnesque) and two races of b l a c k - t a i l deer (Odocoil-eus hemionus columbianus Richardson, Qdocoileus hemionus sltkensls Merriam) the dry-matter intake f o r varying rates of growth during early phases of growth. The p r i n c i p l e s used i n t h i s determination have been developed on animals other than deer. This f a c t i n no way a l t e r s t h e i r v a l i d i t y when applying them to di f f e r e n t species. "Progress i n a l l science has consistently demonstrated that we are l i v i n g i n an orderly universe and that the basic laws apply generally I f one can but f i n d the means fo r doing research and expressing r e s u l t s on comparable bases. Progress i n comparative n u t r i t i o n o f f e r s ample evidence that t h i s f i e l d Is no exception, that each species i s not a spe c i a l creation functioning i n i t s own peculiar manner, but rather that the s i m i l a r i t i e s are f a r more s t r i k i n g than the differences (Guilbert and L o o s l l , 1951, p. 4°)• EXPERIMENTAL 1. Animals and Housing In the spring of 1956 a deer experimental unit was established at the University of B r i t i s h Columbia Research Farm #2 located at Oyster River, Vancouver Island, B. G. B l a c k - t a i l fawns, captured i n the f i e l d , were brought to the Farm from areas i n Alaska, C a l i f o r n i a , and Vancouver Island. These areas were representative of the northern, southern, and middle reaches of b l a c k - t a i l range, res p e c t i v e l y . Mule deer fawns were taken from scattered points throughout southern B r i t i s h Columbia. The animals were confined i n separate pens assembled on the east side of a large c a t t l e barn. Individual pens measured sixteen square feet i n area with sides four feet i n height. The siz e of the pen r e s t r i c t e d the animal's a c t i v i t y , an important f a c t o r i n i t s energy demands. On the average of twice each week the animals were given access to an indoor exercise area f o r periods of about one hour's duration. 2. Planes of N u t r i t i o n and Rations Two planes of n u t r i t i o n were established i n order to produce d i f f e r e n t i a l growth r a t e s . The high plane of n u t r i -t i o n , designed to achieve an optimal rate of growth, offered 1 2 a daily caloric Intake of approximately 5 times the basal net-energy metabolism i n terms of digestible energy. This ratio i s based on Brody's (1945) observations on maximal rela-tive food capacities of several species. The animals placed on the low plane of nutrition were offered a daily caloric intake of 60 per cent of the high plane l e v e l . The low plane of nutrition was designed to permit growth at a minimal rate. In the absence of experimental data on deer metabolism, Brody's formula, Cal./day = 39«5 x body weight i n pounds 0.734 (Brody, 1945), was used as the basis for computing the planes of caloric intake. Maintenance requirements were assumed to be two times the basal metabolic rate i n terms of digestible energy. The diet chosen for the pre-weaning period of growth was condensed milk (Pacific Brand ) to which was added a min-eral supplement. Comparison of the mineral constituents of doe's and cow's milk showed certain deficiencies i n cow's milk. The composition of the mineral supplement which was added to the milk ration is given in Table 1. Table 1 Mineral Supplement Added to Condensed Milk Ration Magnesium Chloride 50 grams Ferric Citrate 13 grams Copper Sulphate 0.6 grams 63.6 grams ^Produced by Fraser Valley Milk Producers Association, Vancouver, B. C. I n i t i a l l y , a regimen of milk feeding was instituted under which the daily computed ration was distributed in six, approximately equal, aliquots over the twelve hour period from 0600 to l800 hours. In the second week of June the milk-feeding schedule was changed to four feedings per day given at the hours of 0600, 1000, lij.00, and 1800. The standard ration was the low plane level of diet plus an additional three ounces of milk per twenty-four hours. This standard was adhered to u n t i l weaning appeared to be im-minent. Body weights of 15 pounds for males and 12 pounds for females were a r b i t r a r i l y selected as representing the point of physiological development at which weaning could take place. Several days before the complete elimination of milk from the diet, the milk ration was reduced to induce the animals to eat pellets, thus preparing the rumen for i t s func-tion as the principal chamber of digestion and cellulose break down. The pelleted ration designated as TJ.B.C. 15-56 was sub stituted for milk at weaning. The proximate composition of the ration i s given i n Table 2. For purposes of comparison the proximate composition of two pellet rations fed to experi-mental deer of the 1952 colony in previous studies at the University of Brit i s h Columbia i s given in Table 3. Individual consumption of pellets was recorded daily with allowance for spillage. A small amount of fresh pasture grasses was fed from time to time. The caloric value of this supplement i s negli-gible . 4 TABLE 2 Proximate Composition of Experimental Pellet Ration 15-56 Moisture Protein Pat Fibre N.F.E. Ash 13.0 16.0 4.8' 8.1 50.8 7.3 TABLE 3 Proximate Composition of Experimental Rations 14 and 15 Moisture Protein Fat Fibre N.F.E. Ash No, llj. 10.45 16.35 3.17 8.59 53.45 8.0 No. 15 10.4 15.4 4.0 8.4 53.6 7.7 3. Methods of Determining D i g e s t i b i l i t y Two methods of determining d i g e s t i b i l i t y were used, (a) Total Collection During the period of growth when the animals were on milk a total collection of feces voided was made on selected animals. I n i t i a l l y the collection t r i a l s lasted for three days; later the t r i a l s were extended to five-day periods. Feces were picked up as soon after voiding as they were observed. Care was taken to prevent their being contaminated by urine, shav-ings, or d i r t . The wet weight was recorded, and the feces were then oven-dried at 77 degrees Centigrade for periods ranging from 22 to 32 hours. The dried feces were then weighed and ground through a 60-mesh screen i n a Wiley M i l l . 5 A sample from each 2lj.-hour c o l l e c t i o n period was ex-ploded i n a Parr Peroxide Bomb Calorimeter. The combustion value which was obtained was m u l t i p l i e d by the dry weight of the feces co l l e c t e d during the 2i|-hour period from which the sample was taken (Appendix I I I ) . The c a l o r i e values of each 2lj.-hour period were then summed. This sum, which i s the c a l -o r i c value of a l l feces voided during the t r i a l period, i s then divided by the c a l o r i c value (gross energy) of a l l food ingested during the t r i a l . The quotient times 100 gives the percentage of undigested c a l o r i e s f o r the period. Subtract-ing t h i s percentage from 100 gives the per cent d i g e s t i b i l i t y (or c o e f f i c i e n t of d i g e s t i b i l i t y ) of the r a t i o n , (b) Chromagen Method Reid et a l . (1950) introduced the chromagen method of d i g e s t i b i l i t y i n 1950. The r e s u l t s of t h e i r experiment indicated that natural chromagenic substances which were In-di g e s t i b l e and completely recoverable i n the feces were present i n some natural forages, and could be used i n the measurement of d i g e s t i b i l i t y i n ruminants. Fecal samples were dried at 35 degrees Centrigrade and ground through a 60 mesh screen i n a Wiley M i l l . Dis-t i l l e d acetone was used to extract the chromagenic substances i n the feces. Immediately following extraction samples of the f i l t r a t e were brought to an appropriate volume and an absorption curve determined, using a Beckman spectrophoto-meter. Samples of the p e l l e t r a t i o n were treated as above. A comparison of the o p t i c a l density readings of feed and feces at the peak of the absorption curve reveals the per cent d i g e s t i b i l i t y of the ration at the time the feces was c o l l e c t e d . RESULTS 1 . Environmental Factors Temperature ranges were read and recorded d a i l y from a minimum-maximum thermometer, but other environmental stim-u l i , such as humidity and l i g h t i n t e n s i t y , were not measured. The s i t u a t i o n of the pens was such that the effect of these s t i m u l i was believed to be evenly d i s t r i b u t e d throughout the u n i t . No extremes or wide f l u c t u a t i o n s of temperature were recorded. No perceptible change was observed i n food-intake that could be attributed to variations i n temperature. 2 . M o r t a l i t y With respect to the influence of environment on mor-t a l i t y i t would be l o g i c a l to assume that a bias existed i n favor of the Vancouver Island fawns, most of which were born within a few miles of the Oyster River Farm. D i f f e r e n t i a l m o rtality rates were unexpectedly i n favor of the fawns from Alaska and C a l i f o r n i a . None of the Alaska deer died during the summer season, and only a few were distressed by disease or i l l n e s s . Several losses oc-curred i n the C a l i f o r n i a group but the cause of death was not determined. 8 I n t e s t i n a l i n f e c t i o n ("white scours") caused severe losses among the Vancouver Island and Mule deer groups. Other diseases, accidents, and escapes further reduced the number of experimental animals. Of s i x t y - f i v e fawns re-ceived i n spring and early summer only forty-three were on hand at the beginning of autumn. 3 . Growth Data from the TJ. B. C. deer colony of 1952 (Gowan and Wood, 1955) provide the only standards of growth f o r the sub-species 0. h. columbianus. Body weight was used as the most suitable expression of growth. Growth con-stants were calculated which revealed three d i s t i n c t phases of growth between p a r t u r i t i o n and puberty (Table 4) • Phases I and I I were of b r i e f duration with Phase. I l l beginning ap-proximately two weeks following p a r t u r i t i o n . For the 1956 colony growth constants were calculated f o r most of the animals f o r a twelve week period which i n the high plane animals corresponded t o the growth phase I I I mentioned above. The formula by which the constants were calculated I s : In W2 - In W], Constant (K) = j . • • -t- 2 - t x W = Body weight t = time The period of time f o r which growth constants were measured extended from the f i r s t several days following the a r r i v a l of the animals at the Research Farm to the onset of puberty (as evidenced by the appearance of antler buds and sexual behavior i n male fawns) i n several of the high plane animals This was approximately twelve weeks f o r the majority of the animals. Several of the C a l i f o r n i a deer were not received immediately a f t e r capture. In consequence of being several weeks older than the other animals t h e i r growth could be measured only over a shorter period of eight weeks. TABLE 1+ Growth Constants f o r Deer of the 1952 Colony Phase I I I Sex Deer -No. Phase I Phase I I 1 2 \ .080 .030 .053 .0k9 .0I+9 I 7 8 1H .100 .098 .091 .046 .01+7 .050 .011 F .012 M .015 M .011+ i i .011 M .015" M -.015 M .011+ M .021+ M \ TABLE $ Growth Constants for Deer of the 1956 Colony C a l i f o r n i a High Plane Males Deer #1 0.011 2 0.013 5 0.014 20 0.010 25 0.010 Mean 0.120 High Plane Females 4 0.011 7 0.014 8 0.013 12 0.014 13 0.013 21 Q»oi3 Mean 0.01$ Alaska High Plane Males 31 0.016 32 0.014 35 0.015 38 0.020 Mean" 0.01b High Plane Females 30 0.016 37 0.017 Mean 0.017 Vancouver Island High Plane Males Low Plane Males 50 0.017 . 0.010 51 0.017 64 0.012 55 0.015 Mean o.oii 59 0.011 61 0.015 Mean 0.015 High Plane Female 53 0.018 56 0.015 62 0.014 Mean 0.016 Low Plane Males 19 0.012 22 0.008 lean 0.010 Low Plane Females 6 0.011 10 0.010 15 0.012 21 0.010 Mean 0.011 Low Plane Males \3J 0.010 Mean 0.010 Low Plane Females 3 | 0.014 Mean 0.013 TJToT^ TABLE 5 — Continued Mule Deer High Plane Males Deer #90 92 9k 102 Mean 0.019 0.016 0.017 0.015 High Plane Females 97 0,015 101 0.019 Mean 0.017 Low Plane Males 10l+ 105 Mean 0.013 0.011 0.012 Low Plane Females 96 0.011+ Growth constants (Table 5) of the C a l i f o r n i a deer were of the same order-as those of the 1952 deer; those of the Vancouver Island, Alaska, and Mule deer were higher. In comparison with the growth pattern of the 1952 colony, which was even and si m i l a r f o r ten of the eleven animals, the fawns of the 1956 colony showed considerable v a r i a b i l -i t y . h» Energy Content of the Rations (a) Condensed Milk Analysis of the milk of the Columbian b l a c k - t a i l deer has shown that although the percentages of the milk constituents d i f f e r e d from those of condensed milk the c a l o r i c value per f l u i d ounce was almost i d e n t i c a l ( K i t t s , et a l . , 1956). .12 1 TABLE 6 Comparison of the Constituents and Caloric Values of Doe's Milk with that of Condensed Milk 100 gr Doe's Milk (Mean of .3 Samples)' ( K i t t s , et a l . , 19^6) Constituent Grams Cal/g Calories Protein 8.9 5.6 1+9.7 Pat 10.0 9 4 95.0 CHO 1+.1+ l+.i 18.1 162.8 100 gr Condensed Milk (Prom Hawk, Oser, and . . Summerson, 1951+) Constituent Grams Cal/g Cal Protein 7.0 5.6 39.2 Pat 7.9 9 4 71+.2 CHO 9.9 l+.l 1+0.5 153.9 Eight samples of P a c i f i c Condensed milk were analyzed for !dry matter and colo r i c content. One f l u i d ounce of con-densed milk weighed 29.11+9 grams. The dry weight of the eight samples averaged 21+.5 per cent of the wet weight suggesting 7.11+ grams dry s o l i d s per f l u i d ounce. The average c a l o r i c value f o r one gram of dry milk as determined i n the bomb c a l o r i -meter was 6.1 c a l o r i e s . This value compares favorably with that reported by other workers (Hawk, Oser, and Summerson, 1951+; Gaines, 1928; Overman, et a l . , 1939). (b) Pelleted Ration 15-56 Six random-n&amples were analyzed f o r dry matter and c a l o r i c content. The moisture content was 13 per cent; the dry matter of an ounce of p e l l e t s was therefore 21+.62 grams. 13: The average c a l o r i c value f o r one gram (dry weight) of p e l l e t s as determined i n the bomb calorimeter was If.,7 c a l o r i e s . The gross energy of an ounce of p e l l e t s as fed was therefore 115.7 calories (24»62 x If.7). 5. D i g e s t i b i l i t y The data obtained from the digestion t r i a l s was i n -s u f f i c i e n t to y i e l d other than trends i n the d i g e s t i b i l i t y patterns of the animals. As was expected the d i g e s t i b i l i t y of milk was high, the majority of samples showing co e f f i c i e n t s of the order of 90 Per cent or greater. (Table 7) . The d i -g e s t i b i l i t y c o e f f i c i e n t s of the pel l e t e d r a t i o n ranged from 62 per cent to 77 per cent (Table 8 ) , values which approxi-mate those of feed concentrates l i s t e d f o r c a t t l e and sheep (Morrison, 1954)• TABLE 7 D i g e s t i b i l i t y Coefficients of Milk T r i a l Periods Deer June 2 June 19 June 28 July 6 July If? J u l y 25 August 10 No. June 5 June 22 J u l y 2 J u l y 11 J u l y 20 July 30 August 15 51 94 9? 94 56 90 68 79 58 96 93 91 60 95 92 61 93 82 62 97 96 92 91 63 96 94 64 93 99 91 99 96 93 104 95 99 96 105 96 96 3 88 8 (95) 13 19 22 92 i4 TABLE 8 Chromagen Analysis of D i g e s t i b i l i t y of Pel l e t e d Ration 15-56 UBC, 1956 C o l l e c t i o n Per Cent Optical Per Cent Deer No.v Date s Transmission Density D i g e s t i b i l i t y P e l l e t Ration 1 9 9/6 102 9/4 30 9/6 37 9/6 13 9/4 19 9/h 51 9/« 79 0.102 47 0.328 69 49.5 0.306 67 51 0.292 65 $k 0.268 62 78 (?) -50 „ ... 0.301 67 41 0.387 74 P e l l e t Ration 79 0.102 102 9/6 51 0.2Q2 65 9 0 9/6 , 54 0.268 62 61 9/6 41 0.387 74 35 9/6 79 (?) 13 7/7 4».5 0.315 68 19 7/6 41 0.387 73 38 7/18 49 0.310 68 P e l l e t Ration 79 ©.102 55 9/4 46.5 0.332 70 6 53 0.276 6J 9/ 3 0.301 0.260 0.409 0.444 0.367 3o* 7/i7 5b " ' 0.301 67 9/^ 5q 67 IC Ii 6 19 7/7 9 | 9/6 55 61 J6 13 7/6 43 0.367 7 2 56 8/10 39 . 75 5 8/12 36 77 6. Dry-Matter Intake Pood intake was recorded on the basis of ounces of milk drunk and ounces of p e l l e t s eaten. Dry-matter coef-f i c i e n t s were applied to the sum of a l l food ingested through-out the study period, and the ca l o r i c value of the dry-matter was computed. Columns 2 and 5 of Tables 1 1 a through l i d give the dry-matter intake ( i n terms of gross calories i n -gested) of f o r t y - f i v e animals for periods of eight to twelve weeks• The summation of dry-matter intake does not reveal the d a i l y v a r i a t i o n i n quantity of food ingested p a r t i c u l a r l y among the animals on the high plane of n u t r i t i o n . In some Instances the v a r i a b i l i t y could be att r i b u t e d to i l l n e s s or nervousness; i n others the v a r i a b i l i t y could not be accounted f o r . \ 16 TABLE 9 Average Growth Gain f o r 8i|.-Day Period During Ea r l y Phases of Growth CALIFORNIA1 HIGH PLANE OF NUTRITION 18.6** pounds LOW PLANE OF NUTRITION 13.9 ALASKA 4HH5- HIGH PLANE OF NUTRITION 26.5 LOW PLANE OF NUTRITION 15.2 VANCOUVER ISLAND HIGH PLANE OF NUTRITION 22.1 LOW PLANE OF NUTRITION 12.3 MULE DEER HIGH PLANE OF NUTRITION 37.6 LOW PLANE OF NUTRITION 1 7 . 7 VANOOUVER ISLAND mm (Nursed does and fed ad l i b i t u m upon weaning) 3 5 4 Exclude numbers 1, 2, ij., 5 (early records Incomplete). Average lowered by several animals with" history of I l l n e s s . *** Exclude number 38 (early record incomplete). DISCUSSION 1. Significance of Growth i n Dry-Matter Intake Dry-Matter intake i s i n part a function of the net energy requirements • Although the c a l c u l a t i o n of the net energy requirement i s l a r g e l y independent of the rate of growth, dry-matter intake w i l l vary to some considerable extent depending upon the rate of growth achieved. The ex-planation l i e s i n the f a c t that growth rates are dependent i n large measure on the plane of n u t r i t i o n . Diminishing returns lower the e f f i c i e n c y of food u t i l i z a t i o n i n moving from low to high planes. Thus the increment of net energy y i e l d i s lower on a large quantity of ingested food than on a smaller quantity. A complete pic t u r e of growth i s lacking for the deer of the 1956 colony due to the circumstances by which they were co l l e c t e d . The exact date of b i r t h was known f o r only two of the C a l i f o r n i a group which were born into c a p t i v i t y . Records of t h e i r immediate post-natal weight gains and food intake were not av a i l a b l e . A l l of the remaining animals were procured i n the w i l d , and no knowledge was had of t h e i r e a r l y growth and n u t r i t i o n . Hence, the growth picture f o r the v i t a l period embracing growth phases I and I I could 18 not be determined. The importance of immediate post-natal growth i s shown i n the comparison of weight gains (Table 9) a n <* growth rates (Tables 1+ and 5) between the 1952 colony and the 1956 colony. Growth constants f o r Phase -III were higher i n the Vancouver Island, Alaska, and Mule deer groups, yet the ab-solute weight gain was lower. The explanation seems to l i e i n the low growth rates which probably occurred i n the im-mediate post-natal period (Phases I and I I ) . Growth i n the l a t e r phases attempts to make up that which was l o s t i n i t i a l l y . This phenomenon was observed i n one of the animals of the 1952 colony (Cowan and Wood, 1955). The larger size of the mule deer at the end of the summer, despite growth rates that did not d i f f e r s i g n i f i -cantly from those of-the Alaska and Vancouver Island black-t a i l s , would indicate a larger r e l a t i v e size at b i r t h . B i r t h weights of most mammals tend to be a constant per-centage of the mother 1 s normal body weight. This i s i n agreement with the well-established f a c t that mule deer are, on the average, larger than the b l a c k - t a i l race (Cowan, 1 9 3 6 ) . The question has been raised as to whether the size differences r e s u l t from genetic differences i n growth po-t e n t i a l or--if they are -due to better n u t r i t i o n and environ-ment on the mule deer ranges. Because of the s i m i l a r growth 19 rates there was no evidence either way i n ear l y growth other than s l i g h t differences i n body weight. Later stages of grosth revealed s i g n i f i c a n t differences i n ske l e t a l s i z e and body weight (Table 1 0 ) . The genetic f a c t o r i s the only ex-planation f o r there were no differences i n n u t r i t i o n a l and environmental h i s t o r y . The v a r i a b i l i t y of the growth constants w i t h i n each group may be due i n part to i n d i v i d u a l differences i n genetic growth p o t e n t i a l . Much of i t , however, resulted from the high incidence of i l l n e s s among the animals which tended to disrupt the growth pattern. TABLE 10 Body Weights of Animals on High Plane of N u t r i t i o n February, 1957 C a l i f o r n i a Weight Average Males i n lbs. Weight In l b s . 81+ 62 Ik 69 67 62 67 73.0 67.8 Vancouver Island ~~" ' Weight Males i n lbs, #50 51 55 59 6 i Females 53 62 56 71 66 66 59 73 59 57 71 Average Weight i n l b s . 67.0 62.3 38 Females 30 37 81 86 64 7 2 Mule Beer 83.5 Males Weight #90 iol+ 92 117 68.0 9l+ 105 102 97 Females #97 95 105.8 95.0 21 2. Influence of D i g e s t i b i l i t y on Dry-Matter Intake The phenomenon of d i g e s t i b i l i t y i s complex, "Di-gestion c o e f f i c i e n t s f o r any p a r t i c u l a r species vary with environmental conditions, stage of plant maturity, animal s e l e c t i v i t y , s i t e and s o i l conditions, species of animal, age of animal, plane of n u t r i t i o n and n u t r i t i v e balance of the d i e t (Cook et a l . , 1951, p. 336)." The importance of d i g e s t i b i l i t y i s pointed out by Maynard (1951, p. 21^9), ". . . the aetual value of ingested nutrients i s dependent upon the use which the body i s able to make of them. The f i r s t consideration here Is d i g e s t i -b i l i t y , since undigested nutrients do not get i n t o the body proper." Thus, the d i g e s t i b i l i t y of a r a t i o n tends to re-f l e c t the net energy value of the r a t i o n , that i s , the higher the d i g e s t i b i l i t y , the higher the net energy. The accuracy of a digestion t r i a l can be influenced by the quantity of food Ingested d a i l y during the t r i a l per-i o d . I t i s 1 desirable to feed the same amount of r a t i o n each day t o avoid fluctuations i n both ingested energy and ex-creted energy. Some variations i n d a i l y food consumption were noted i n our t r i a l animals but the variations seldom were of an order of more than ten per cent. Dukes (1955) observed that In the post-natal growth period the digestive tr a c t of the ruminant Is not unlike the simple canal of Carnivora. The passage of milk through the 22 t r a c t probably does not take over 2lf hours. On t h i s assump-t i o n food-intake was measured beginning 2ij. hours p r i o r to the f i r s t feces c o l l e c t i o n and ended 2i| hours before the f i n a l 2^ hour feces c o l l e c t i o n . Other workers (Moore and Wright, 193i|.) have used markers t o measure the rate of pas-sage of food through the alimentary t r a c t . In the present experiment markers were not used f o r fear of the deleterious eff e c t which they might have exerted on the animals' growth and development • Several t o t a l feces coll e c t i o n s were made when the animals were on p e l l e t s e x c l u s i v e l y . The purpose of these co l l e c t i o n s was to provide a check on the chromagen method of d i g e s t i b i l i t y determination. Studies of the rate of passage of foodstuffs through the digestive t r a c t of a rumin-ant (Ewing and Wright, 1918) indicated that at least 72 hours must pass a f t e r ingestion before the average food residue w i l l appear i n the feces. Because i t s components are r e a d i l y broken down and assimilated milk i s especially adapted f o r the digestive tra c t of young animals. Morrison (1954) pointed out that the proportions of the components i n milk vary widely be-tween species. D i g e s t i b i l i t y , growth and condition may be seriously affected i f the milk fed to a young animal does not match that of i t s mother with respect to the proportions of the nutrients. The percentage of f a t i s es p e c i a l l y 23 c r i t i c a l ; a higher than normal percentage r e s u l t s i n d i a r -rhea and lowered d i g e s t i b i l i t y . I n the present experiment the high c o e f f i c i e n t s of d i g e s t i b i l i t y attained on the milk diet indicated that differences i n f a t content between doe's milk and condensed cow's milk were s l i g h t . Diarrhea (scour-ing) occurred sporadically, but mainly as a r e s u l t of intes-t i n a l i n f e c t i o n . Prom lat e June to l a t e J u l y when the animals were fed milk e x c l u s i v e l y the d i g e s t i b i l i t y c o e f f i c i e n t s declined from 98 per cent to about 91 P© r cent. The explanationfbr the decline seems to l i e i n the p h y s i o l o g i c a l and biochemi-c a l changes concomitant with growth which occurred i n the digestive system. Lactose, the only s i g n i f i c a n t carbohydrate present i n both cow's and doe's milk, i s a disaccharide which must undergo hydrolysis or s p l i t t i n g into monosaccharides before absorption can take place. The enzyme which catalyzes the above reaction is lactase. Studies on the amount of lactase a c t i v i t y present i n the digestive tract of the young of sev-er a l species show that lactase a c t i v i t y decreases as the a n i -mal approaches the age of weaning (Bailey, et a l . , 19£6). No studies have been undertaken on lactase a c t i v i t y In deer, but there i s no reason to believe that i t would d i f f e r s i g n i -f i c a n t l y from that i n other species. Therefore changes i n lactase a c t i v i t y would be r e f l e c t e d i n similar changes i n 24 d i g e s t i b i l i t y c o e f f i c i e n t s . The change was best evidenced by the animals on the high plane of n u t r i t i o n . Coefficients of the animals on low plane were complicated by other factors as explained below, and did not exhibit the steady decline of the high plane animals. The p r i n c i p l e of diminishing returns i s applied by Brody (1945) to food intake. With a r i s e i n the l e v e l of food intake the e f f i c i e n c y of u t i l i z a t i o n of the r a t i o n de-c l i n e s . In terms of energetics, as gross energy of the d a i l y r a t i o n i s increased the percentage of d i g e s t i b l e energy de-creases. E a r l i e r i t was pointed out that the l e v e l of milk and p e l l e t intake was determined by c a l c u l a t i n g the mainten-ance and growth requirements of animals of a given body weight from Brody's formulae. The formulae are u s e f u l as general p r i n c i p l e s , but an accurate application would have to be based on experimental work with the actual species employed. To avoid f l u c t u a t i o n s i n d a i l y intake the milk r a t i o n was modified a r b i t r a r i l y from the o r i g i n a l computa-t i o n . The l e v e l of milk intake therefore may have varied considerably with respect to the actual energy needs of the animals. For example, i f the l e v e l of milk intake i n the early weeks was low r e l a t i v e to the maintenance and growth requirements of the animals, then the per cent d i g e s t i b i l i t y could have been expected to be higher. That the l e v e l was low at that time i s indicated by the f a i l u r e of the animals to achieve the rate of growth of the 1952 colony. 25 The p r i n c i p l e of diminishing returns appears evident i n the d i g e s t i b i l i t y c o e f f i c i e n t s for the t r i a l s of August tenth to August f i f t e e n t h . Three of the t r i a l animais (Nos. 5>1, 58, and 6ij.) were on milk e x c l u s i v e l y at that time. In the attempt to bring about weaning the d a i l y milk r a t i o n of these animals was cut to between s i x t y and seventy per cent of the calculated l e v e l . The d i g e s t i b i l i t y c o e f f i c i e n t s f o r these animals averaged 93 per cent, a higher f i g u r e than the average found i n the t r i a l s two w e e k s e a r l i e r . Brody (1945, p. 90) states, "Underfed animals develop a 'growth debt' which may enable them to u t i l i z e food more e f f i c i e n t l y than w e l l -fed animals." In e a r l y September when a l l of the animals were on the p e l l e t e d r a t i o n the d i g e s t i b i l i t y c o e f f i c i e n t s of four mule deer were found to be lower than those of three Van-couver Island b l a c k - t a i l s . The mule deer had been weaned for w e l l over a month; weaning of the Vancouver Island deer had taken place only two weeks e a r l i e r . I t was observed that the a b i l i t y of a l l weaned animals on high planes of nu-t r i t i o n to approach the l i m i t of t h e i r calculated d a i l y r a -t i o n increased with time. Several reasons are suggested f o r t h i s trend. The intake curve could have been calculated i n -co r r e c t l y ; rumen development may have been incomplete; a 'psychological' adjustment to weaning may have diminished food intake. 26 3 . Dry-Matter Intake The significance of dry-matter intake can better be appreciated i f the amount of feed ingested can be trans-l a t e d into one of the categories of dietary energy. A pound of milk does not equal a pound of p e l l e t s i n c a l o r i c content. Further, the two foodstuffs d i f f e r i n d i g e s t i b l e and metabol-i z a b l e energies so that the f i n a l c a l o r i c value to the animal of an equal mass of each r a t i o n w i l l not be the same. This f i n a l value i s net energy, " I t i s the energy convertible into the maximum amount of work, milk, egg, meat, etc (Brody, 191+5, P. 3k) »tt Tha direct computation of the net energy value of a foodstuff i s d i f f i c u l t . Species d i f -ferences, digestion, metabolism, s p e c i f i c dynamic action, and plane of n u t r i t i o n are complicating factors i n the process of converting gross energy into net energy. Net energy values may, however, be estimated by ind i r e c t means based on c e r t a i n broad p r i n c i p l e s of metabolism and n u t r i t i o n which have been found to apply to a l l homeotherms. D i g e s t i b i l i t y c o e f f i c i e n t s of a r a t i o n are valuable i n assessing the net energy of the r a t i o n i n that they re-f l e c t net energy values more accurately than the gross energy. The digestion t r i a l s which were run on the animals yielded s u f f i c i e n t data from which the net energy value of both the milk and p e l l e t rations could be estimated. 27 The net energy needs of the animals can be divided into two basic requirements. One i s the basic maintenance requirement of the animal's c e l l u l a r mass. To t h i s energy requirement must be added the increment necessary to support muscular work and a c t i v i t y . For the captive deer t h i s incre-ment was considered to be very small and was incorporated into the c a l c u l a t i o n of "resting metabolism," to be explained. The other category of net energy requirement i s growth, which i s represented by the c a l o r i c value of the increase i n body mass. The maintenance'requirement can be estimated from the basal metabolic ra t e . Basal metabolism Is a function of body surface area and body mass and i s c a l c u l a t e d from the equa-t i o n Cals./2l|. hrs. = 70.5 Wkg 0.73. Brody (1945) shows th i s equation to be constant f o r mature animals of a l l species. The case for growing animals i s different since the regula-tory mechanisms f o r heat production and control are not f u l l y developed. Growth also involves an energy cost d i f f i c u l t to separate from basal metabolism. The basic maintenance cost i n growing animals i s termed "resting metabolism" (Brody, 1945) • The l e v e l of resting metabolism ranges from 70 per cent to 90 per cent above the basal metabolism of mature animals of corresponding weight depending on weight and age. In Tables 11a through l i d an attempt was made to equate f o r f o r t y - f i v e experimental animals the known food 28 TABLE 11a Caloric Intake and Output of High Plane Males Twelve Week Period Pre-pubertal Growth Phase (Alaska Group Ten Weeks) (1) (2) (3) (4> (5) (6) Milk Calories P e l l e t Calories Total Net Ingested Net Energy Ingested .Net Energy Caloric Gross (63 Per Cent „ Gross (50 Per Gent Intake Energy Gross) Energy Gross) (3) & (5) CALIFORNIA i * 2* 5* 20 25 8,7l4 10,194 11,125 40,185 19,627 5,489 6,422 7,009 25,316 12,365 91,093 79*533 *?'!2 2 34,680 67,742 45,547 39,766 26,646 17,340 33,871 51,036 46,188 42,656 I 46,236 ALASKA 31 32 38* 17,6c3l l?,754 16,852 none 11,139 12,445 10,477 none 84,388 77,221 83,463 75,487 42,194 38,610 41,731 37,743 51,055 52,208 37,743 VANCOUVER ISLAND 50 51 55 I 9 61 32,444 20,k40 31,514 i9»?53 29,652 18,681 31,471 19,827 29,822 18,788 74,215 52,367 68,20k 84,041 37,107 26,183 34,102 22,889 42,020 MULE DEER 90 92 94 102 16,530 10,414 21,750 13,703 18,896 11,904 20,010 12,606 170,079 213,8l4 168,691 115,200 85,039 106,907 84,346 57,600 MM Eight weeks T A B L E 1 1 a C o n t i n u e d ( 7 ) ( 8 ) <9) do) R e s t i n g M e t a b o l i s m 1+0,013 3 2 , 7 2 5 31,385 38,675 40,310 G a i n L b s . W e i g h t G a i n 1 8 , 5 15*0 10.5: 10.0 1 6 . 5 16,650-13,500 .9,450 .9,000 l4,05G T o t a l E s t i m a t e d C a l o r i c O u t p u t ( 7 ) & ( 9 ) 56,66, 40,*S2*>-39 4 8 , 4 7 2 40,012 23.0 1 9 . 0 1 9 . 5 1 8 . 5 2 0 , 7 0 0 17,100 17,550 16,650 60,118 g p f c 5 6 , 0 4 2 45,963 3 6 , 2 9 5 4 7 , 3 0 3 4 1 , 3 5 3 4 1 * 5 0 2 27.0 2 0 . 5 2 6 . 5 16.5 25.0 2 k , 3 0 0 18,450 2 3,850 14,850 2 2,500 70,26 71i _. , fci+,002 60,540 76,457 59,648 56,400 41.0 39.0 3 9 . 5 3 0 . 5 36,900 35,100 35,550 27,450 12440 30 TABLE l i b C a l o r i c Intake and Output of High Plane Females Twelve Week Period Pre-pubertal Growth Phase (Alaska Group Ten Weeks) d 1) (?2> ^(3) m Milk Calories ^ P e l l e t Calories Total Net , Ingested Net Energy Ingested Net Energy Caloric Deer Gross (63 Per Gent . Gross (£0 Per Cent Intake No # Energy Gross) , Energy Gross) (3) & (5) CALIFORNIA 4 * 11,082 6,982 70,7i+7 35,373 7 12,309 7,755 110,745 55,372 . 8 13,409 8,448 83,116 4l*553 50,001 ,553 12 12',352 7,7652 116,294 58*147 65,929 13 9,687 6,103 120,294 60,147 bb,250 21 12,182 7,675 120,023 60,012 b7 ,bB7 ALASKA 30 18,527 11,672 75,4?7 37,743 49 415 37 15,143 9,54o 98,260 49,130 58,b7Q VANCOUVER ISLAND 53 27*918 17,588 80,573 4©,287 57,875 56 25,634 16,1U9 102,884 51,442 b7;5?l 62 36,040 24,251 39,651 19,826 U , 5 3 l MULE DEER 97 20,010 12,663 185,126 92,563 105,226 101 19,653 12,003 155,617 77,809 WMZ #Eight weeks 31 TABLE l i b — Continued (7) Resting Metabolism 3,765 ,,4^ 75 il.0,905 57,320 P4P 49,682 (8) Weight Gain Lbs. 14.5 20.5 17.5 20.5 22.0 23.5 (9) Calories i n Weight Gain 13,050 18,450 15,750 I8,k50 19,800 21,150 (10) .. Total Estimated Caloric Output and Storage (7) & (9) 815 w,__ 70,832 35,105 52,210 21.0 23.0 18,900 20,700 44,030 50,976 38,527 27.0 26.0 18.5 24,300 23,400 16,650 68,330 ^7177 61,880 58,755 37.0 39.5 33,300 35,500 I ,180 tS2 32 TABLE 11c Caloric Intake and Output of Low Plane Males Twelve Week Period Pre-pubertal Growth Phase (Alaska Group Ten Weeks) (1) (2) (3) (4) (5) (6) Milk Calories Ingested Net Energy Deer .Gross (63 Per Cent No. Energy .. Gross) CALIFORNIA 19 22 ALASKA 19458 35,405 33 15,482 VANCOUVER ISLAND 58 64 33,925 38,493 MULE DEER 104 105 19,662 22,375 12,259 22,305 9,754 21,373 24,251 12,363 14,096 P e l l e t Calories SPotal Net Ingested Net Energy Caloric . Gross (50 Per Cent Intake Energy .. Gross) (3) & (5) 61,615 15,375 30,807 7,682 51,442 25,721 24,160 12,080 25,432 12,716 73,354 36/677 51,024 25,512 13,066 J 9 J W 35,1+75 33453 49;Q4g 39,b0b-TABLE 11c — Continued 33 C7) Resting Metabolism (.Less 10%) Weight Gain Lbs. (9) Calories i n Weight Gain (10) Total Estimated Calorie Output and Storage "(7) & (9) 35,807 30 ,54l 15.5 7.5 13,950 6,750 37,291 28,591 15.5 13,950 42,54i 35,878 35,700 12.5 12.0 11,250 10,800 47,128 46,500 42,84© 39,895 19.5 15.5 17,550 13,950 60,390 53JBfe 34 TABLE l i d cCalorie Intake and Output of Low Plane Females .Twelve Week Period Pre-pubertal Growth.Phase (Alaska Group Ten Weeks) fe) fe) (4) Cf5> ((6) v Milk Calories . P e l l e t Calories Total Net Ingested Net Energy' Ingested Net Energy Caloric Beer Gross (63 Per Cent Gross (50 Per Cent Intake ,No.. Energy „. Gross) Energy CALIFORNIA Gross) (-3) & (5) 6 10 15 23 11,463 12,055 12,182 12,394 7,222 7,595 7,675 7,808 73,637 67,973 72,250 70,747 36,818 33,986 36,125 35,373 14,040 41,^1 43,800 43,181 ALAS!KA 21,488 21,954 13,537 13,831 41,963 42,194 20,981 21,097 34,518 .34,928 VANCOUVER ISLANB None MULE DEER 96 37,106 23,377 34,479 17,239 4o,6l6 35 TABLE l i d — Continued (7) (8) (9) (10) Total Estimated Resting | Calories Caloric Output Metabolism Weight i n and Storage (Less 10#) Gain Lbs. Weight Gain (7) & (9) 38,820 16.0 l 4 , k 0 0 53,220 36,klk lif.O 12,600 49,01k 36,202 15.0 13,500 U9,702 34,54o 15.0 i3,5oo k6,Qko 36,4l4 14.0 12,600 k?,Qlk 35,743 12.5 11,250 k6,99J -34,941 18.0 16,200 5 i , i 4 i 36 intake expressed as net energy with the calculated net energy requirement for maintenance and growth. A l l of the animals were i n pre-pubertal phases of growth, and the per-iod of time covered i n the tables i s from eight to twelve weeks depending on the history of the i n d i v i d u a l animals. Column (1) l i s t s the animals according to subspecies, sex, and plane of n u t r i t i o n . The values i n column (2) were computed by multiply-ing the t o t a l ounces of milk consumed by lj.2.3 c a l o r i e s . In estimating the net energy value of the ingested milk as given i n column (3) the d i g e s t i b i l i t y c o e f f i c i e n t s of the milk were used. These c o e f f i c i e n t s ranged between 85 per cent and 98 per cent. Ninety per cent was a r b i t r a r -i l y selected as the c o e f f i c i e n t f o r a l l animals f o r the en-t i r e period; i t i s probably a conservative value. To com-pute net energy from d i g e s t i b l e energy Brady's data, which showed the net to be about 70 per cent of the d i g e s t i b l e , was used (1945* PP. 80-85). Net energy then becomes 63 per cent of the gross. The values i n column (ij.) are computed by multiply-ing the t o t a l ounces of p e l l e t s consumed by 115.6 c a l o r i e s . The average d i g e s t i b i l i t y c o e f f i c i e n t f o r the p e l l e t s was 70 per cent. Again taking the net energy as 70 per cent of d i g e s t i b l e , net becomes about 50 per cent of the gross. (Column 5 ) . In computing the resting metabolism of the fawns 37 (column 7) the assumption was made that the metabolism of growing deer would approximate that of growing c a t t l e . I t was necessary to compute the basal metabolism f o r each a n i -mal. Basal metabolism (Cals./2l+ hrs.) f o r the weight range of each animal was regressed against time• Total basal meta-bolism f o r the period was computed by summing the squares beneath the curve. Basal metabolism was increased by 70 per cent to give r e s t i n g metabolism. In accordance with the findings of Moulton (1923) and Armsby (1917) that a n i -mals on a low plane have a lower maintenance requirement, the metabolism figure f o r the low plane animals was a r b i -t r a r i l y reduced ten per cent. Column (9) was computed by multiplying each pound of weight gain by 900 c a l o r i e s , a figure which represents the stored energy i n a pound of average body mass. Body composition varies with physiological age and the n u t r i t i v e state of the animal. Prom data given by Morrison (1954, p. 202) on the average composition of beef steers at v a r i -ous stages' of growth the c a l o r i c value of a pound of average body mass increased from approximately 730 calories at 100 pounds body weight to 980 c a l o r i e s at 1|00 pounds body weight. At a body weight of 700 pounds, the c a l o r i c value was ap-proximately 1,300 pounds. Hawk et a l . (1954, P- 1078) l i s t the f a t component as 12.5 per cent and the protein component as llj . , 4 per cent of an adult human body mass. On th i s basis 38 a pound of average body mass would have a c a l o r i c value of approximately 89O c a l o r i e s . Similar composition figures f o r adult humans are given by West and Todd (19£2, p. 1+07). Prom t h e i r figures a pound of average body mass had a c a l o r i e value of approximately 1,000 c a l o r i e s . In the absence of any knowledge of body composition or changes therein i n the deer the a r b i t r a r y value of 900 calories was applied to the weight gains of a l l the animals throughout the early growth phases. I f the foregoing computations were accurate and the assumptions on which they were based v a l i d , then column (6), Total Net Caloric Intake, would exactly balance column (10), Total Net Caloric Output and Growth Storage. A c t u a l l y , the figures of twenty per cent of the animals were within f i v e per cent of balancing exactly; f o r t y per cent were w i t h i n ten per cent; but thirty-three per cent were out of balance by twenty per cent or greater. In assessing these r e s u l t s i t was apparent that a number of corrections could be made, the magnitude of the correction varying with the i n d i v i d u a l animal's plane of n u t r i t i o n , health, previous n u t r i t i o n a l h i s t o r y , etc. I t was f e l t that discussion of the corrections and the reasons underlying them should be l i m i t e d to the text as a l t e r a t i o n of the figures i n Tables 11a through l i d wauld unnecessarily complicate the presentation. Almost a l l of the discrepancies i n balancing were such that the energy output and storage value were higher 39 than the value of energy input. This would suggest that one or both of the c o e f f i c i e n t s of net energy of the two foods were too low. A l l of the animals whose balances d i f f e r e d less than s i x per cent were on the high plane of n u t r i t i o n . With the exception of Deer #6l the ratios of p e l l e t net energy to milk net energy range from 6 to 1 to 10 to 1. Of the animals whose balances d i f f e r e d by twenty per cent or more the r a t i o s of p e l l e t net energy to milk net energy were a l l under 5 to 1; four were about 1 to 1; and f o r three of the animals the rati o s were 1 to 2 . I t is apparent that the discrepancies i n balancing are least when the milk r a t i o n i s proportionally small i n the ov e r a l l d i e t . I t was concluded that i f a l l other factors were reasonably correct the net energy value of the milk as com-puted was too low. Corrections upward on the order of 5 to 10 per cent would bring the balances more i n l i n e f o r almost a l l of the animals. As pointed out e a r l i e r the amount of milk fed d a i l y was determined a r b i t r a r i l y , hence the plane of n u t r i t i o n dur-ing the period of milk feeding i s not accurately known. That i t was somewhat low i s borne out by (1) the f a i l u r e of the animals to achieve optimum growth while on milk and ( 2 ) the a b i l i t y of the animals to consume the f u l l d a i l y r a t i o n with palpable willingness to take even more. In i t s e l f a low plane of n u t r i t i o n would bring about a r i s e i n the net energy value of the ration (Blaxter and Graham, 1955)• The principle just mentioned would probably raise the net energy value of the pellet ration for the low plane animals. Upon weaning the animals were divided into two planes of nutrition. A slight difference in d i g e s t i b i l i t y of the pellets was noted between high and low plane animals, although other factors, principally physiological age, tended to obscure the comparisons in d i g e s t i b i l i t i e s . Several of the animals (numbers 50# 55, 61+, 10l+* 105, 25) suffered illnesses in degrees ranging from moderate to severe. The disruption i n metabolism and food intake was probably sufficient to make their record of limited value (Dubois, 19ll+). It should be pointed out that such animals as numbers 1, 2, 12, 13, 21, and 90 were among the healthiest animals, and had discrepancies of no more than ten per cent in their energy balances. Most of the animals were procured in the wild, and we had no knowledge of their prenatal and immediate post-natal nutritional history. Several of the animals came to the experimental farm i n an obvious state of inanition. Their condition undoubtedly affected growth, metabolism, and e f f i -ciency of food u t i l i z a t i o n . At the other extreme, Alaska #38 appeared, superficially, to be obese upon a r r i v a l . That i t brought some energy with i t from Alaska i s evidenced by the fact that i t gained more weight on less calories than any other animal save one. The c a l o r i c value of a pound of gain was probably lower i n the low plane animals than i n the high plane groups. Some l i p i d s must be present i n a l l body growth gains as struc-t u r a l constituents of new tissue (e.g., nervous tissue,), but storage of f a t would not take place i n the low plane animals. With increasing physiological age there i s a greater a b i l i t y to store f a t i f on a high plane of n u t r i t i o n . Consequently a s l i g h t correction downward f o r the low plane animals and a s l i g h t correction upward for the high plane animals could be made i n the c a l o r i c value of a pound of gain. Another consideration i n explaining the discrepancies i n energy balances i s the probable v a r i a t i o n i n metabolic e f f i c i e n c y of the in d i v i d u a l animals• Just as there are genetic differences i n growth so there may be genetie d i f -ferences In metabolism not only between subspecies but among the animals w i t h i n each taxonomic group. 42 Application of the above corrections could bring a l l of the energy computations within a ten per cent range of a perfect balance. Prom this we assume that the bases on which the computation were made are reasonably correct. Given complete growth data for the several subspecies of deer i t i s possible to compute the net energy requirements for any plane of nutrition during the prepubertal phases of growth. 4» Subspeciflc Differences i n Growth and Nutritional Efficiencies There are apparent differences in growth gain (Table 9)» efficiency of the gain (Table 12), average net calories per pound of gain (Table 13)* growth constants (Table 5), and length of pre-weaning period (Table li|.)» between the four subspecific groups. The mule deer exhibit the best e f f i -ciency in the u t i l i z a t i o n of food energy, and the Galifornia deer the least. It i s regrettable that the records of several of the largest and healthiest-of the California deer were not complete, for their inclusion would have improved the e f f i -ciencies of the group. The greatest similarity i n these categories is shown by the Vancouver Island and Alaska black-t a i l s . An important difference is that although total net-energy requirements were about equal, the amount of milk calories required by the Vancouver Island deer was about 43 d o u b l e t h a t o f t h e A l a s k a d e e r ( T a b l e 15). I n v i e w o f t h e b e t t e r g r o w t h p e r f o r m a n c e o f t h e 1952 b l a c k - t a i l c o l o n y t h e " h i g h p l a n e " l e v e l o f n u t r i t i o n o f t h e 1956 b l a c k - t a i l c o l o n y w o u l d m o r e c o r r e c t l y b e t e r m e d a " m e d i u m - h i g h p l a n e . " D a t a f r o m t h e 1952 c o l o n y ( T a b l e l 6 ) , w a s u s e d t o c o m p u t e t h e h i g h - p l a n e n e t e n e r g y r e q u i r e m e n t f o r t h e V a n c o u v e r I s l a n d s u b s p e c i e s . T A B L E 12 E f f i c i e n c y o f G a i n H I G H P L A N E OF N U T R I T I O N S u b s p e c i e s C a l i f o r n i a 27.5$ A l a s k a 32.0 V a n c o u v e r I s l a n d 31.0 M u l e D e e r 35.3 LOW P L A N E ,0F N U T R I T I O N C a l i f o r n i a 26.0 A l a s k a 27.0 V a n c o u v e r I s l a n d 23 .0 M u l e D e e r 29.0 T A B L E 13 A v e r a g e N e t C a l o r i e s C o n s u m e d p e r P o u n d o f G a i n H I G H P L A N E OP N U T R I T I O N S u b s p e c i e s C a l i f o r n i a 3099; A l a s k a 2 l 0 7 V a n c o u v e r I s l a n d 2308 M u l e D e e r . 2^6 1 LOW P L A N E * OP N U T R I T I O N C a l i f o r n i a 30I4.9 A l a s k a 2£l6 V a n c o u v e r I s l a n d 2878 M u l e D e e r 2432 N e t c a l o r i e s c o n s u n e d n o t c o r r e c t e d f o r l o w p l a n e l e v e l o f n u t r i t i o n . 45 T A B L E 14 A p p r o x i n a t e N u m b e r o f W e e k s i n P r e - W e a n i n g P e r i o d S u b s p e c i e s C a l i f o r n i a A l a s k a V a n c o u v e r I s l a n d M u l e D e e r D a t e W h e n A p p r o x i m a t e R a n g e M a j o r i t y N u m b e r o f o f B i r t h D a t e s A n i m a l s W e a n e d W e e k s o n M i l k M a y 5 t o M a y 1 2 J u n e 8 t o J u n e If? J u n e 1 2 t o J u n e 19 J u n e 17 J u l y 30 A u g u s t 22 J u n e 12 t o J u n e 19 A u g u s t 2 5 t o 6 6-1/2 t o 7-1/2 9 t o 10 6 t o 7 E x c l u d e N o s . 1, 2, 4, 5, a n d 20. T A B L E 15 P e r c e n t a g e o f M i l k C a l o r i e s i n T o t a l N e t C a l o r i c C o n s u m p t i o n H I G H P L A N E C a l i f o r n i a A l a s k a V a n c o u v e r I s l a n d M u l e D e e r 18J* 22 38 13 46 Because the circumstances of feeding were the same for the mule deer as for the rest of the colony i t i s as-sumed that t h e i r growth rate was below the optimum l e v e l and the high plane animals were a c t u a l l y on a medium-high plane. TABLE 16 Total Estimated C a l o r i c Output and Storage of 1952 Colony Vancouver Island Deer for 84-Day Period Following P a r t u r i t i o n (1) (2) (3) (k) (5) Resting Calories Total Estimated Metab- Weight i n Caloric Output ollsm Gain Lbs. Weight Gain (2) & (4) l ' 54,697 34.O 30,600 8 5 , 2 9 7 2 61,135 39.5 35,550 q6,685 59,075 31.5 28,350 87,425 53,635 33.3 29 , 970 83,605 7 56,525 36.2 32,580 8Q,105 8 54,590 33.4 30,060 84,650 5 59,947 38.5 34,650 54*597 6 55,930 34.0 30,600 86,530 1 H 61,880 36.1 32,490 94,370 2 H 57,417 38.0 34,200 91,617 5. Experimental Results Applied to F i e l d Conditions Leopold et a l . (1951) U3ed dry-matter Intake as one of the factors on which they based recommendations on the management of deer range i n C a l i f o r n i a . Their estimates of browse consumption were based on experimental t r i a l s with captive adult mule deer. Tables (17) and (18) attempt to apply OVLV experimental r e s u l t s to f i e l d conditions. Growth differences between the several races were allowed f o r , and several assumptions (noted below) were necessary. Cowan (1936) noted differences i n body weight among the several races of 0. h. columblanus. " . . . a gradual increase In body size takes place from the south to the north, specimens from . . . B r i t i s h Columbia greatly ex-ceeding those from coastal C a l i f o r n i a , both i n l i n e a l and mass requirements, (p. 220)." The Alaskan b l a c k - t a i l s (0. h. sitkensis)are c l a s s i -f i e d as a race apart (Cowan, 1936). Brooks (p. 213) states that s i t k e n s i s i s a c t u a l l y a larger animal than the black-t a i l of Vancouver Island. On the basis of body weights of our animals, both fo r the summer period, 1956 and February, 1957* the above size differences are apparent even i n ea r l y growth. Only high plane animals were compared. The Alaska deer, both males and females, are larger than the other two b l a c k - t a i l races. Although the C a l i f o r n i a deer average weights are 48 larger than the Vancouver Island deer, allowance must be made f o r the older age of the former. C a l i f o r n i a deer #1 and #2 were as much as two and one-half months older than any of the Vancouver Island animals. TABLE 17 Wet Energy Requirements f o r Twelve Week Period Following P a r t u r i t i o n DEER C a l i f o r n i a Medium-high plane Low plane (1) (2) p ) Average Average Estimated Average Weight B i r t h Weight (lbs.) ^ Gain Weight (lbs.) 84 Days p.p. (lbs.) 6.75 6.75 27.35 20.65 20.6 13.9 (4) Calories i n Gain 18,540 12,510 Alaska Medium-high plane Low plane 6.75 6.75 33.25 21.95 26.5 15.2 23,850 13,680 Vancouver Island High plane r 6.75 Medium-high plane 6.75 Low plane 6.75 Mule Medium plane 8.5 Low plane 8.5 41.75 28.85 19.05 46.1 26.2 35.0 22.1 12.3 37.6 17.7 31,500 19,890 11,070 33,840 15,930 p.p. = post p a r t u r i t i o n 49 T A B L E 17 — C o n t i n u e d : (5) (6) (7) T o t a l A c t i v i t y N e t . C a l o r i e s R e s t i n g I n c r e m e n t R e q u i r e d M e t a b o l i s m (20% R . M . ) ( C o l s . l i ,5,6), 37,527 7,505 63,572 34,360 - 46,870 41,203 8,241 73,294 34,614 - 48,294 46,410 9,282 87,192 37,830 7,566 65,286 33,910 - 44,980 49,087 9,817 92,744 40,607 - 56,597 1 T A B L E 18 D r y - M a t t e r I n t a k e f o r T w e l v e Week P e r i o d F o l l o w i n g P a r t u r i t i o n T o t a l N e t C a l o r i e s R e q u i r e d R a t i o n A 6.1 C a l / g r a 90$ D i g e s t i b l e R a t i o n B 5.2 C a l / g m 70$ D i g e s t i b l e N . E . * 70% D i g . N . E . 702 \ D i g . N . E . 50% D i g 45,000 26.3 l b s . 39.0 l b s . 54.7 l b s . 50,000 2 8 . 9 43.3 60.6 55 , o o o 31.8 47.6 66.7 60,000 34.8 52.0 72.8 65,000 37.3 56.3 78.8 70,000 46.2 6o.6 84.9 75,000 43.1 65.0 91.0 80,000 45.9 69.3 97.0 85,000 48.8 73.7 103.1 90,000 51.7 78.0 109 . I 95,000 54.6 82.1 115.2 * N . E . = N e t E n e r g y 51 T A B L E 1 8 — C o n t i n u e d R a t i o n C R a t i o n D 5.2 C a l / g m 50$ D i g e s t i b l e 5.2 C a l / g m 30$ D i g e s t i b l e N . E . 70% D i g . _ . „ _ N . E . 50% B i g . N . E . Wo D i g . . . N . E . 50% D i g , 54.7 76.4 290.9 127.3 60.6 81+.9 101.0 li+1.6 66.7 9 3 4 111.2 155.6 72.8 101.9 121.3 I69.8 , 78.8 110.1+ 1314 183.9 81+.9 118.8 Up..* 198.1 91.0 127.3 151.6 212.2 97.0 135.8 161.7 2264 103.1 1*44 171.7 21+0.6 109.1 153.0 181.8 251+.8 115.2 l 6 l . 7 191.9 269.9 52 Accurate b i r t h weights exist only f o r Vancouver Island deer. To sim p l i f y b i r t h weight comparisons (Table 17) the average b i r t h weight of the 1952 colony was used f o r a l l j b l a c k - t a i l s . Since b i r t h weights tend to be a percentage of the mother's body weight, the b i r t h weights are probably s l i g h t l y high for the C a l i f o r n i a deer and s l i g h t l y low f o r i • the Alaska deer. The assumption was made that the b i r t h weight of the mule deer was 8.5 pounds. Most of the f i r s t recorded weights of this group were heavier than the above weight but a l l of the animals were known to be at least several days o l d . The c a l o r i c value of the gain i n body weight was as-sumed to be 900 c a l o r i e s per pound. Resting metabolism was computed as before (Table 11), and an increment of twenty per cent of r e s t i n g metabolism was added to compensate for a c t i v i t y of animals i n the wi l d state. Total net energy requirements (column 7) serve as the basis for estimating the dry-matter intake necessary to sustain the animals for the twelve week period following b i r t h . Most of the animals on the medium-high and high planes of n u t r i t i o n reach puberty at the end of t h i s period. Table (18) gives the approximate amounts of feed intake for feeds with di f f e r e n t d i g e s t i b i l i t i e s . For each d i g e s t i b i l i t y c o e f f i c i e n t (except Ration A) two net energy 53 values are given. "Net energy values are considerably more variable than t o t a l digestible nutrients (Morrison, 1954* p. 54)»" Important factors which reduce the net energy value of a d i e t are: (1) High levels of food intake. (2) A n u t r i t i v e deficiency. (3) Low f a t content. (4) Single food d i e t s , excepting milk, as opposed to combination of feeds. Ration A could only be m i l k , and a 90 per cent d i -g e s t i b i l i t y c o e f f i c i e n t would apply only while the animals were on milk e x c l u s i v e l y , i . e . before the development of the rumen. I t is not l i k e l y that the net energy value of the milk would vary, hence only one value i s given. D i g e s t i b i l i t y Coefficients of Certain Forage Species on C a l i f o r n i a Deer Ranges TABLE 19 Sagebrush Bitterbrush 52 Live Oak and Chamise 54 Live Oak 20 ( B i s s e l l , et a l . , 1955) 54 T A B L E 2 0 D i g e s t i b i l i t y C o e f f i c i e n t s o f C e r t a i n F o r a g e . S p e c i e s o n E a s t e r n W h i t e - T a i l D e e r R a n g e s A c o r n s 36.6 D o g w o o d 28.3 W i l l o w 28.9 ( F o r b e s , I9I4.I) T a b l e 19 w a s c a l c u l a t e d f r o m B i s s e l l ' s d i g e s t i b i l -i t y s t u d i e s o n C a l i f o r n i a m u l e a n d b l a c k - t a i l d e e r . T h e f i g u r e s i n T a b l e 20 w e r e t a k e n f r o m F o r b e s 1 d a t a o n w h i t e -t a i l d i g e s t i b i l i t i e s . I t w o u l d a p p e a r t h a t R a t i o n s C a n d D ( T a b l e 18) a r e m o s t r e p r e s e n t a t i v e o f r a n g e f o r a g e s p e c i e s . I n a s s e s s i n g r a n g e f o r a g e f o o d s f o r t h e i r n u t r i t i v e v a l u e , t h e c h a n g e s i n c o m p o s i t i o n m u s t b e c o n s i d e r e d . N u t r i -t i v e v a l u e s c h a n g e t h r o u g h o u t t h e p l a n t |s l i f e c y c l e ( G o r d o n a n d S a m p s o n , 1939) a n d t h r o u g h o u t t h e y e a r ( H e l l m e r s , I9I+O). D i f f e r e n t p a r t s , o f t h e p l a n t a l s o d i f f e r i n c o m p o s i t i o n ( R e y n o l d s a n d S a m p s o n , 1943)• D i g e s t i b l e p r o t e i n may a l s o d i f f e r b e t w e e n p l a n t s p e c i e s w i t h a p p r o x i m a t e l y e q u a l c r u d e p r o t e i n c o e f f i c i e n t s ( H a g e n , 1953). T h e a m o u n t o f d i g e s t i b l e p r o t e i n h a s a n i m -p o r t a n t e f f e c t o n t o t a l d i g e s t i b i l i t y o f t h e r a t i o n ( M o r r i s o n , 1954). The p e r i o d o f l i f e w i t h w h i c h we a r e c o n c e r n e d ( i . e . t h e f i r s t t w e l v e w e e k s o f l i f e ) g e n e r a l l y c o i n c i d e s w i t h t h e s e a s o n a l p e r i o d o f o p t i m a l n u t r i t i v e v a l u e o f t h e f o r a g e p l a n t s w h i c h t h e y o u n g a n i m a l s m a y u t i l i z e . SUMMARY AND C O N C L U S I O N S F o r t y - f i v e f a w n s o f t h e y e a r , r e p r e s e n t a t i v e o f r a c e s o f O d o c o i l e u s h e m i o n u s c o l u m b i a n u s , O d o c o i l e u s h e m i o n u s s i t k e n s i s , a n d O d o c o i l e u s h e m i o n u s h e m i o n u s , w e r e r a i s e d t o g e t h e r u n d e r s i m i l a r e n v i r o n m e n t a l c o n d i t i o n s . A c o n d e n s e d m i l k ( c o w s ) r a t i o n w i t h m i n e r a l s u p p l e -m e n t was f e d t o a l l a n i m a l s u n t i l w e a n i n g w h e n a p e l l e t c o n -c e n t r a t e , U . B . C . D e e r 15-56, w a s s u b s t i t u t e d . A d a i l y r e c o r d o f a l l f o o d i n g e s t e d w a s k e p t f o r a l l a n i m a l s . T h e a n i m a l s w e r e w e i g h e d a t l e a s t t w i c e e a c h w e e k a n d t h e w e i g h t s d u l y r e c o r d e d . A c a l c u l a t i o n w a s made f o r e a c h a n i m a l t o d e t e r m i n e t h e t o t a l n e t c a l o r i c o u t p u t a n d s t o r a g e f o r a t w e l v e w e e k p e r i o d o f p r e - p u b e r t a l g r o w t h . T h e c a l c u l a t i o n w a s b a s e d o n t h e a s s u m p t i o n t h a t m e t a b o l i c m a i n t e n a n c e ( r e s t i n g m e t a b -o l i s m ) i n y o u n g r u m i n a n t s w a s a t t h e l e v e l o f s e v e n t y p e r c e n t h i g h e r t h a n t h e b a s a l m e t a b o l i s m f o r m a t u r e a n i m a l s o f t h e same b o d y w e i g h t . B a s a l m e t a b o l i s m , i n t u r n , w a s c o m p u t e d f r o m t h e e q u a t i o n , Cal/2lj. h r s . i s e q u a l t o 39*5 * l b s . ( B o d y w e i g h t ) G * 7 3 4 . p 0 r a n i m a l s o n t h e l o w p l a n e o f n u t r i t i o n t h e r e s t i n g m e t a b o l i s m w a s r e d u c e d t e n p e r c e n t , a n a r b i t r a r y f i g u r e b a s e d o n l o w e r m a i n t e n a n c e n e e d s f o r 56 57 l o w p l a n e a n i m a l s . E a c h p o u n d o f w e i g h t g a i n w a s c o m p u t e d a s r e p r e s e n t i n g n i n e h u n d r e d c a l o r i e s o f s t o r e d e n e r g y . T h e g r o s s e n e r g y o f t o t a l f o o d c o n s u m p t i o n o v e r t h e t w e l v e w e e k p e r i o d w a s c o n v e r t e d i n t o n e t e n e r g y . G r o s s e n e r g y v a l u e s f o r t h e m i l k a n d p e l l e t r a t i o n s w e r e d e t e r -m i n e d b y c o m b u s t i o n i n a P a r r p e r o x i d e bomb c a l o r i m e t e r . T h e d i g e s t i b i l i t y o f b o t h r a t i o n s w a s d e t e r m i n e d t h r o u g h t o t a l f e c e s c o l l e c t i o n s a n d t h e c h r o m a g e n m e t h o d . T h e a v e r -a g e d i g e s t i b i l i t y c o e f f i c i e n t f o r t h e m i l k w a s n i n e t y p e r c e n t a n d f o r t h e p e l l e t s , s e v e n t y p e r c e n t . T h e n e t e n e r g y was e s t i m a t e d a s s e v e n t y p e r c e n t o f t h e d i g e s t i b l e e n e r g y . T h e n e t e n e r g y v a l u e o f t h e f o o d c o n s u m e d w a s c o m -p a r e d w i t h t h e n e t e n e r g y v a l u e o f t h e r e s t i n g m e t a b o l i s m a n d w e i g h t g a i n f o r t h e t w e l v e w e e k p e r i o d . T h e o r e t i c a l l y b o t h v a l u e s s h o u l d b e e q u a l . F o r t y p e r c e n t o f t h e a n i m a l s h a d v a l u e s t h a t b a l a n c e d w i t h i n t h e r a n g e o f t e n p e r c e n t . T h e v a l u e s o f o n e - t h i r d o f t h e a n i m a l s w e r e o u t o f b a l a n c e t b y t w e n t y p e r c e n t o r m o r e . V a l i d c o r r e c t i o n s a p p l i e d t o t h e v a l u e s o f t h e l a t t e r a n i m a l s r e d u c e d t h e m a g n i t u d e o f t h e d i s c r e p a n c i e s . T h e r e s u l t s s u p p o r t t h e m e t h o d o f c o m -p u t i n g n e t e n e r g y r e q u i r e m e n t s . O n t h i s b a s i s , g i v e n (1) t h e p a t t e r n o f g r o w t h a n d (2) t h e p l a n e o f n u t r i t i o n , t h e n e t e n e r g y r e q u i r e m e n t f o r t h e s u b s p e c i e s o f O d o c o i l e u s h e m i o n u s d u r i n g t h e e a r l y p h a s e s o f g r o w t h may b e c a l c u l a t e d . G i v e n t h i s n e t e n e r g y 58 r e q u i r e m e n t a n d t h e d i g e s t i b i l i t y c o e f f i c i e n t o f t h e r a t i o n t h e d r y - m a t t e r i n t a k e c a n b e e s t i m a t e d . Q u a n t i t a t i v e d i f f e r e n c e s i n n e t e n e r g y r e q u i r e m e n t s o f t h e f o u r g r o u p s o f d e e r r e f l e c t e d d i f f e r e n c e s i n b o d y w e i g h t a n d p l a n e s o f n u t r i t i o n . E a c h o f t h e f o u r r a c e s d i f f e r e d i n ( 1 ) A v e r a g e n e t c a l o r i e s p e r p o u n d o f g a i n ; ( 2 ) E f f i c i e n c y o f g a i n ; ( 3 ) L e n g t h o f t h e p r e - w e a n i n g p e r i o d ; a n d (Ij.) P e r c e n t a g e o f m i l k c a l o r i e s i n t o t a l n e t c a l o r i c c o n s u m p t i o n . G r o w t h c o n s t a n t s f o r t h e A l a s k a , V a n c o u v e r I s l a n d , a n d m u l e d e e r w e r e a p p r o x i m a t e l y t h e s a m e . The g r o w t h c o n s t a n t s o f t h e C a l i f o r n i a d e e r w e r e s l i g h t l y l o w e r . T h e a b o v e d i f f e r e n c e s m a y be o n l y a p p a r e n t f o r t h e f o l l o w i n g f a c t o r s c o m p l i c a t e d t h e e x p e r i m e n t : (1) D i f f e r e n t b i r t h d a t e s , m o s t o f t h e m u n k n o w n , o f t h e a n i m a l s . ( 2 ) N o k n o w l e d g e o f t h e p r e - n a t a l a n d i m m e d i a t e p o s t - n a t a l n u t r i t i o n a l h i s t o r y . ( 3 ) No k n o w l e d g e o f g e n e t i c v a r i a b i l i t y b e t w e e n i n d i v i d u a l s o f t h e same g r o u p . F a i l u r e t o p l a c e t h e a n i m a l s o n l o w a n d h i g h p l a n e s o f n u t r i t i o n d u r i n g t h e p e r i o d o f m i l k f e e d i n g . (5) V a r y i n g d e g r e e s o f s i c k n e s s i n s e v e r a l o f t h e a n i m a l s d u r i n g t h e e x p e r i m e n t . 59 The value of the knowledge of dry-matter Intake during the early phases of growth l i e s i n I t s being a r e f l e c t i o n of the net energy demand of the animals during a c r u c i a l stage of growth. The n u t r i t i o n a l status of the young deer during t h i s growth phase w i l l profoundly affect (1) the animal's future growth and development (McCay et a l . , 1935) and (2) the chances of s u r v i v a l during the f i r s t year of l i f e (Robinson, 1957). "The struggle f o r existence Is a struggle f o r free energy (Boltzmann)*" 60 BIBLIOGRAPHY 1. Association O f f i c i a l A g r i c u l t u r a l Chemists, 1955. Methods of Analysis, Assoc. O f f i c . Agr. Chemists, Washington, D. C. 2. B a i l e y , C. B., W. D. K i t t s , and A. J. Wood, 1956. The Development of the Digestive Enzyme System of the Pig During i t s Pre-Weaning Phase of Growth, Canadian Jour. of A g r i . S c i . , 36: 51-58. 3. B i s s e l l , H. D., B. H a r r i s , H. Strong, and P. James, 1955. The D i g e s t i b i l i t y of Certain Natural and A r t i f i c i a l Poods Eaten by Deer i n C a l i f o r n i a , . . C a l i f . P i s h and Game, i f l : 57-78. 4. Blaxter, K. L. and N. McC. Graham, 1955, Methods of Assessing the Energy Values of Poods f o r Ruminant Animals, Proc. of the Nut. S o c , l i j . : 131-139. 5. Brody, S. and R. C. Proctor, 1932. Growth and Develop-ment with Special Reference,to Domestic Animals, Missouri Agr. Exp. Sta. B u l l . , 166. 6. Brody, S., 1945. Bioenergetics and Growth, Reinhold Publishing Company, New York. 7. Brooks, A., 1939. Hunting the Columbian Black-T a i l Deer i n North American Big Game, Chas. Scribners Sons , New York. r 8. Cook, C. W. and L. E. H a r r i s , 1951. A Comparison of the Lignin Ratio Technique and the Chromagen Method of Determining D i g e s t i b i l i t y and Forage Consumption of Desert Range Plants by Sheep, Jour. Anim. S c i . 10: 565-573. 9. Cook, c\ W.j L. A. Stoddart, and Lor i n E. H a r r i s , 1951. Measuring Consumption and D i g e s t i b i l i t y of Winter Range Plants by Sheep, Jour. Range Mgt. l±i 3.35-346. 10. Cowan, I . MoT., 1936. D i s t r i b u t i o n and Va r i a t i o n i n Deer (Genus Odocoileus) of the P a c i f i c Coastal Region of North America, C a l i f . F i s h and Game, 22:155-246. ~ : ~ ~ " 61 11. Cowan, I . MoT. and A. J . Wood, 1955. The Growth Rate of the Black-Ta l l Deer (Odocoileus hemionus oolumbianus) Jour. Wldl. Mgt. 19:331-336. 12. DuBols, E. F., 1914. The Total Energy Requirement i n Disease, Cornell Univ. Med. B u l l e t i n , 4:1-12* 13. Dukes, H. H., 1955. The Physiology of Domestic Animals. Comstock Press, Ithaca, New York. 14. Ewing, P. V., and L. H. Wright, 1918. A Study of Physical Changes i n Feed Residues which Take Place i n Cattle During Digestion. Jour. Agr. Res., 13: 639-646. 15. Forbes, E. B., L. F. Macy, A. LeRoy V o r i s , and C. E. French, 1941. The Digestive Capacities of the White-Tall Deer, Jour. Wldl. Mgt., 5:108-114. 16. Forbes, E. B. and R. W. Swift, 1943. Conditions Affect-ing the D i g e s t i b i l i t y and the Metabollzable Energy of Feed f o r C a t t l e , Penn. Agr. Exp. Sta. B u l l . , 454. 17. Gaines, W. L., 1928. The Energy Basis of Measuring Milk Y i e l d i n Dairy Cows, I l l i n o i s Agr. Exp. Sta. B u l l . , 308. 18. Gordon, A., and A. W. Sampson, 1939. Composition of Common C a l i f o r n i a F o o t h i l l Plants as a Factor i n Range Management, Univ. C a l i f . Agr. Exp. Sta. B u l l . , 627. 19. G u i l b e rt, H. R., and J . K. L o o s l i , 1951. Comparative N u t r i t i o n of Farm Animals, Jour. Anlm. S c i . 10:22-41. 20. Hagen, H. L., 1953. N u t r i t i v e Value f o r Deer of Some Forage Plants i n the Si e r r a Nevada, C a l i f . F i s h and Game, 39:163-176. 21. Hawk, P. B., B. L. Oser, and W. H. Summerson, 1954. P r a c t i c a l Physiological Chemistry. McGraw-Hill Book Co., New York. 22. Hellmers, H., 1940. A Study of Monthly V a r i a t i o n i n the N u t r i t i v e Value of Several Natural Winter Deer Foods, Jour. Wldl. Mgt.. 4:315-325. 23. K i t t s , W. D., I . McT. Cowan, J . Bandy, and A. J . Wood, 1956. The Immediate Post-Natal Growth i n the Columbian Black-Tailed Deer i n Relation to the Composition of the Milk of the Doe, Jour. Wldl. Mgt.. 20:212-214. 62 24. Leopold, A. S., T. Riney, R. McCain, and L. Tevis, J r . ; 1951. The Jawbone Deer Herd, C a l i f . Dlv. F i s h and Game, Game B u l l . 4. 25. Lofgreen, G. P., 1951. The Use of Digestible Energy i n the Evaluation of Feeds, Jour. Anlm. S c i . , 10: 344-351. ! — 26. Lusk, G., 1917. Science of N u t r i t i o n , W. B. Saunders Co., New York. 27. Lusk, G., 1921. The Physiological Effect of Under-n u t r i t i o n , Physiological Reviews, 1:523-552. 28. Maynard, L. A., 1951. Animal N u t r i t i o n , McGraw-Hill Book Company, New York. 29. Mendell, L. B., and R. B. Hubbell, 1935. Relation of the Rate of Growth to Diet, Jour. Nutr. 10:557-563. 30. M i t c h e l l , H. H«, 1932. The E f f e c t of the Amount of Feed Consumed by Cattle on the U t i l i z a t i o n of I t s Energy Content, Jour. Agr. Res., 45:163. 31. Moore, L. A., and 0. B. Winter, 1934. Rate of Passage of Inert Materials Through the Digestive Tract of the Bovine, Jour. Dairy S c i . , 17:297-305. 32. Morrison, F. B., 1954. Feeds and Feeding, Morrison Publ. Co., Ithaca, New York. 33. Moulton, C. R., 1923. Normal Growth of Domestic Animals, Missouri Agr. Exp. Sta. Res. B u l l . 62. 34. McCay, C M . , M. F. Crowell and L. A. Maynard, 1935. The E f f e c t of Retarded Growth upon the Length of L i f e Span and Upon the Ultimate Body S i z e , Jour. Nutr., 10:63-79. 35. Osborne, T. B. and L. B. Mendell, 1926. The Relation of the Rate of Growth to Diet, Jour. B i o l . Chem. 69:661-673. ' ! "~~ " 36. Overman, 0. R«, 0. F. Garrett, K. E. Wright, and F. P. Sanmann, 1939. Breed Differences i n Composition of M i l k , I l l i n o i s Agr. Exp. Sta. B u l l . 457. 37. ReId, J . T., P. G. WooIfoik, C. R. Richards, R. W. Kaufmann, J . K. L o o a l l , E. L. Turk, J . I . M i l l e r , and R. E. Blaser, 1950. A New Indicator Method f o r Determination of D i g e s t i b i l i t y and Consumption of Forages by Ruminants, Jour. Dairy S o l . , 33:60-71. 63 38. R o b i n s o n , D . , 1951. P r e l i m i n a r y S t u d i e s u p o n t h e E f f e c t o f L o g g e d O v e r A r e a s o h Q u a l i t y a n d S i z e o f D e e r P o p u l a t i o n s o n V a n c o u v e r I s l a n d , ( P a p e r g i v e n a t A n n . M e e t i n g N o r t h w e s t S e c . W l d l . S o c , 1957, S e a t t l e , ? / a s h . ) . ( M i m e o . ) 39. S m i t h , A . D . , 1952. D i g e s t i b i l i t y o f Some N a t i v e F o r a g e s f o r M u l e D e e r , J o u r . W l d l . , M g t . , 16:309-312. 4 0 . S w i f t , R. W . , 1948. D e e r S e l e c t M o s t N u t r i t i o u s F o r a g e , J o u r . W l d l . M g t . , 12:109-110. 4 1 . S w i f t , R. W . , a n d C . E . F r e n c h , 1954. E n e r g y M e t a b o l i s m a n d N u t r i t i o n , S c a r e c r o w P r e s s , W a s h i n g t o n , D. C . 4 2 . W e s t , E . W . , a n d W. R . T o d d , 1952. T e x t b o o k o f B i o -c h e m i s t r y , The M a c M i l l a n C o m p a n y , New Y o r k . APPENDIX I I Animal Weight Records \ Body Weights f o r Comparative Growth Periods of High Plane Males CALIFORNIA M No. 1 20.5 21.0 No. 2 13.0 ; lif.5 No. 5 13.0 , li+.0 No. 20 11.5 11.5 No. 25 9.5 . 10.0 J u n e 6 13 26 23.0 25.0 28.0 16 .0 17 .0 19.0 15.5 16.5 19.5 12.5 13.5 14.0 11.5 13.0 13.5 -57 28.5 21.5 19.5 14.5 l4 .0 32.0 24.0 21.5 13.0 14.5 11 36.0 27.0 23.0 13.0 13.5 39.0 28.0 23.5 13.5 15.5 I F A u g u s t 1 V 15 14.5 IT.© 20.0 21.5 17.0 20.0 23.0 26.0 ALASKA June No. 31 9*5 12.0 No. 32 10.5 12.0 No. 35 9.5 10.5 No. 38 VANCOUVER ISLAND J u l y 9 16 23 14.0 15.0 16.5 14.0 l4 .5 15.5 13.0 l4 .0 15.5 17.5 19.0 No. 50 8.5 9.0 11.0 No. 51 6.0 6.5 ~ 7.5 No. 55 8.5 10.0 11.5 No. 59 8..5 9.5 11.5 No. 6 l 9.0 10.0 12.5 MULE DEER No. 90 10.5 12.0 14.0 No. 92 19.0 20.0 21.5 No. 94 12.0 14.0 17.0 No.102 12.5 12.5 l4 .0 13.0 9.0 l4 .0 13.0 13.5 18.0 23.0 18.5 16.0 20.0 25.0 19.5 16 .0 "10" 17,5 16.5 16.5 20.0 15.5 12.0 17.5 14.5 16.5 22.0 28.5 20.0 17.5 A u.,g u s t 6 ij - 20 21.0 22.5 25.0 18.0 20.0 23.0 18.5 20.5 22.5 23.5 27.5 29.0 17.0 12.5 16.5 l 6 . 0 17.0 18.5 15.0 18.5 16.5 18.0 29.0 39.0 25.0 22.0 20.0 15.O 20.5 17.0 20.5 32.0 45.0 31.5 25.5 -27 28.0 25.5 26.0 31.5 24.0 17.5 24.0 .18.0 23.0 36.0 50.0 36.0 30.0 September 3\ 10 17 32.5 29.5 29.0 35.5 27.0 19.5 27.5 20.0 27.0 39.0 53.0 40.5 33.5 36.0 33.0 31.5 39.0 31.0 23". 0 29.5 22.5 30.5 46.0 60.O 45.o 38.5 4 f . 5 36.0 35.0 51.5 68.0 5i.o 43.o Body Weights for Comparative Growth Periods of High Plane Females CALIFORNIA • • .- -M a y •*& —IT No. k llf.5 15.5 No. 7 11.0 No. 8 8.0~ 9.0 No. 12 10.0 11.0 No. 13 io.5 12.0 No .21 n . 5 12.0 ALASKA June " 2 T " No. 30 8.0 9.0 No. 37 9.0 10.0 J u n e 6 13 26 17.0 12.0-10.5 12.0 li+.O 13.5 21.0 16.5 12.0 i5.o 17.5 16.0 9 J u 1 y . 16 23 11.0 12.0 13.5 12.5 13.5 15.5 ~ 2 7 23.0 18.0 12.5 16.5 18.0 17.5 ^ 0 15.0 18.0 25.0 18.5-lk.O 18.5 19.5 18.5 J u 18.0 20.0 27.0 21.0 16.0 21.0 22.0 21.5 29.0 23.5 18.0 23.5 24.O 24.O A u g u s t 13 20 21.0 23.0 23.0 25.0 ~Z5 ~2T 25.0 28.5 A u g u s t 1 - 8 27.0 21.5 26.0 28.0 28.5 28.5 2k.0 26.5 30.0 32.0 T5 30.0 25.5 30.5 32.5 35.0 September 1—10 17 29.0 31.5 35.5 32.0 34.5 35.5 VANCOUVER ISLAND No. 53 7.5 No. 56 10.5 No. 62 6.5 8.5 11.0 8.0 10.0 13.5 9.5 12.5 15.5 11.5 13.5 16.0 12.0 15.0 17.5 1J+.0 16.0 20.5 15.0 19.0 22.0 15.0 21.5 2k.0 16.0 21+.5 27.0 17.0 28.0 30.0 19.0 31.0 33.0 22.0 3k.5 36.5 25.0 MULE DEER No. 97 13.0 15.5 No.101 10.5 13.0 17.5 16.0 18.5 18.0 20.0 18.5 22.5 21.0 26.0 21+.5 29.0 27.0 33.0 30.5 36.5 34.0 i+0.5 39.0 k5.o i+5.5 50.0 50.0 Body Weights f o r Comparative Growth Periods of Low Plane Males CALIFORNIA ^W1. a y - J u n e J u l y A u g u s t No No M a y JJ u n e J ± / A u g u t 21+ 31 F ~ 1 3 — 2 0 27 4 .11 18 ,25 1 8 15 . 19 8.0 9.0 11.0 12.0 13.0 13.5 13.5 15.5 16.5 19.0 20.5 22.5 23.5 . 22 10.0 11.5 13.5 li+.o 14.5 14.0 13.0 12.5 il+.0 14.0 15.0 16.0 17.5 ALASKA June J u 1 y A u g u s t September ~2T~ 2~ 9 16 23 30 6 13 20 -27 3\. r i o 17 No. 33 7.5 9.0 11.0 13.0 li+,5 17.5 18.5 19.0 19.5 20.0 23.0 23.0 2i+.0 VANCOUVER ISLAND No. 58 9.5 9.0 11.0 13.0 ll+.O 15.0 16.0 16.5 17.0 18.0 20.0 21.0 22.0 No. 64 6.5 7.0 9.0 10.0 11.0 13.0 li+.O 15.0 15.5 15.5 16.5 18.0 18.5 MULE DEER No.10k 9.0 10.5 13.0 15.0 15.5 16.5 20.5 21.0 23.5 26.0 26.5 27.5 28.5 No. 105 9.0 11.0 13.0 lk.O lk.5 16.5 17.0 18.0 20.0 21.0 22.0 23.5 21+.5 Body Weights for Comparative Growth Periods of Low Plane Females CALIFORNIA '.' ' , J K a 7 J u n e J u l y A u g u s t 2k 31 7 Ik- 21 28 12 19 26 2 9 16 No. 6 No. 10 No. 15 No. 23 9.5 8.0 8.5 9.0 10.0 10.0 io.5 12.0 n . 5 11.0 ll+.O lI^.O 13.5 12.5 13.0 li | . . 0 i i i . 0 ll | . 0 13.5 14.5 13.5 15.0 14.0 16.0 14.0 16.5 16.0 17.5 15.0 17.5 18.5 19.0 16.5 19.5 18.5 20.0 17.5 20.0 19.5 23.0 19.0 21.5 21.0 24.0 20.5 23.0 22.5 25.5 22.0 23.5 24.0 ALASKA June J u 1 y A u g u s t September & 2 . : 9 16 23 30 6 13 20 21 3 10 17 No. 3li No. 3o 7.0 7.0 8.0 7.5 io.5 10.0 12.0 11.0 13.5 12.5 14.5 14.0 16.5 I6.0 18.5 17.5 19.0 18.5 19.5 19.5 21.0 19.5 21.5 19.5 22.5 20.5 MULE DEER No. 96 7.0 8.0 9.0 11.5 12.5 14.0 14.5 16.0 16.5 18.0 20.0 22.0 25.0 APPENDIX III Gross Energy of Fecal Samples Gross Energy Of Fecal Samples (1) (2) (3) (4) (5) Deer No. CALIFORNIA 3 8 13 19 22 ALASKA 30 34 38 Date (1956) 6/2 6/3 6/4 6/2 6/4 7/6 7/7 7/8 7/9 7/10 7/6 7/7 7/8 7/9 7/10 6/2 6/3 6/4 6/19 6/20 6/21 6/19 6/20 6/21 7/15 7/16 7/17 7/18 7/19 Dry Weight of Feces (Grams) 15.0 18.7 10.2 4.6 5.7 71.0 67.9 108.3 107.5 131.3 71.1 52.1 31.7 61.8 54.7 10.9 11.6 8.2 2.9 1.0 3.9 1.3 0 1.6 48.9 41*2 54.8 44.7 84.1 Calorie Value Of Fecal Sample 5.1 5.0 5.0 5.2 5.0 5.1 5.0 4.8 5.2 4.6 5.0 4.1 4.8 4.5 4.8 5.1 5.0 4.9 5.6 5.2 5.1 5.5 5.4 4.7 4.5 4.5 4.4 4.3 Total (3) x (4) 76.5 93.5 51.0 23.9 28.5 362.1 339.5 519.8 559.0 604.0 355.5 213.6 142.2 278.1 262.6 55.6 58.0 40.2 16.2 5.7 19.9 7.1 8.6 229.8 185.4 246.6 196.7 361.6 (1) (2) (3) (4) (5) Deer No. Date (1957) VANCOUVER ISLAND 51 56 58 7/15 7/16 7/18 7/19 7/25 7/26 7/27 7/28 7/29 8/10 8/11 8/12 8/13 8/4 7/15 7/16 7/17 7/18 7/19 7/25 7/26 7/27 7/28 7/29 8/10 8/11 8/12 7/15 7/16 7/17 ,7/18 7/19 7/25 7/26 7/27 7/28 7/29 Dry Weight .of Feces (Grams) 2 4 7.9 i:Z 10.2 12.3 4.9 10.0 9.6 8.Q 6.8 ? 9 $ 23.9 11.5 15.9 15.2 11.9 22.2 20.1 13.2. 12.Q 12.8 47.5 46.5 29.-8 C a l o r i c Value of Fecal Sample .2' 11.3 3.7 7.2 1.3 11.0 .6 4 12.3 5.3 5.5 5.8 5.9 6.1 5.6 5.6 5. 5.7 5.8 5.7 5.3 5.2 5.0 5.2 5.2 6.0 5.6 5.2 .0 .7 45.0 ^ • l 7 4 4 4.8 5.0 5.p 5 4 5.2 5.3 5.2 5.2 5.2 Total (3) x (4) 14.7 4 3 4 15.7 21.2 61.2 65.2 27.4 56.0 30.2 51.8 50.7 39 4 30.8 51.9 124.3 57.5 82.7 79.0 61.9 133.2 112.6 68.6 64.5 60.2 237.5 218.6 131.1 4l .o 20.2 56.5 18.5 38.9 6.8 58.3 18.7 73.9 64.0 (1) (2) (3) (k) (5) Dry Weight Caloric Value Deer Date of Feces of Fecal Total •Mo. (1957) (Grams) Sample (3) x (4) VANCOUVER ISLAND (continued:) 8/10 6 4 5.3 33.9 8/11 l l .k 5.1 58.1 8/12 12.8 5.0 61 .^0 8/13 13.3 5.1 67.8 8/14 10*3 5.0 51.5 6o ' 7/6 .1.7 4.9 8.3 7/7 2.2 5.1 H . 2 7/8 6.8 5.0 34.O 7/9 11.2 5.0 56.0 7/10 5.6 5.0 28.0 7/8 7/9 7/15 3.? 5.5 21.5 7/16 8.4 5.5 46.2 7/17 11.3 5.5 62.2 7/18 6.6 5.5 36.3 7/19 13.6 5.8 78.9 61 7/25 13.9 5.3 73.7 7/26 12.8 5.5 79.4 7/27 5.0 5.3 26. 7/28 2.4 5.5 13.2 7/29 8.7 5.4 47.0 8/10 21.2 4.7 99.6 8/11 21.4 5.1 109.1 8/12 27.5 4.7 129.3 8 / 1 3 51.5 4.& 237.0 8/l4 50.7 4.6 . 233.2 62 6/28 5.0 5.7 28.5 6/29 0.2 5.3 1.0 6/30 2.3 5.8 13.3 7/1 3.0 5.3 15.9 7/6 3.0 4.9 14.7 7/7 0 3.1 5.1 15.8 5.0 4.9 54.5 7/10 10.4 5.2 54.1 (1) (2) (3) (4) Dry Weight Caloric Value Date .of Feces of Fecal (1957) (Grams) Sample VANCOUVER ISLAND (continued) 7/12 11+.9 5 .2 7/16 9 . 5 5 4 7/17 11.9 5.2 7/18 15.6 5 .6 7/19 8 . 5 5 .3 7/25 H . 9 5 .7 7/26 7 .9 5 . 6 7/27 14.8 5 . 6 7/28 12.6 5 .6 7/29 9 .1 5 .5 63 7/6 5 .8 , 5 . 3 7/7 1.6 5 .1 7/8 3 . 8 5 .1 7/9 5 . 6 5 .0 7/10 2 . 5 5 .0 7/15 0 7/16 7.5 5 .8 7/17 9 . 9 5 4 7/18 4 . 7 5 .2 7/19 o.o 5 .3 63 8/10 16.2 8/11 7.5 8/12 20.8 7* MULE DEER 8/l4 9 4 96 7/6 5 . 3 5 .0 7/7 8 .1 £ 4 7/8 8 . 0 4.9 7/9 9 . 6 5 . 0 7/10 11.7 5 .0 105 7/6 2 . 5 4-9 7/7 6.7 5 .0 7/8 6.0 5 .0 7/9 11.8 4.7 7/10 4.8 4.9 (1) (2) (3) (4) (5) Dry Weight Caloric Values Deer Date .of Feces of Fecal Total J o . (1957) (Grams) Sample (3:) x (ii) MULE DEER (continued) 7/25 " 1.8 5 4 9.7 7/26 6.9 5.2 35.9 7/27 9.3 5.5 51.2 7/28 0 7/29 2.1+ 5.0 12.0 90 6/19 6.7 5 4 36.2 6/20 5.6 6.7 37.5 6/21 6.9 64. 6/28 2.3 5.2 14.2: 6/29 3.1 5.2 12.1 6/30 1 4 5.5 7.7 7/1 0 4 5.1 2.1 l O l i 6/28 0 , , _ * 6/29 13.3 3.5 1+6.55 6/30 6.5 6.0 39.0 7/6 9.8 1+.9 48.p 7/7 18.2 1+.6 87.4 7/8 28.4 4.7 133.5 7/9 17.0 4.8 81.6 7/10 21.5 4.9 1054 7/25 0 7/26 11.4 5.1 58.1 7/27 2.9 4.8 13.9 7/28 7.5 .. 4.8 36.0 7/29 3.5 5.0 17.5 APPENDIX IV Constituents of Pelleted Ration 15-56 CONSTITUENTS OF U.B.C.RATION 15-56 Pounds Constituent Per 4,000 l b s . Corn meal 1,200 Bran 550 Beet pulp 400 Molasses 300 Ground Wheat 500 Dehydrated A l f a l f a 400 Soya Meal 200 Copra Meal 150 P i s h Meal 220 Iodized Salt . l+o Bone 40 4,000 APPENDIX I Animal Growth Curves 10£L_ ion 9 10 11 10X3L -P-e-r-i.-oc.-~ -June i n 24 vfeeks --to-r i : : is " x c r T T -12-10.fi.
Thesis/Dissertation
eng
Zoology
Vancouver : University of British Columbia Library
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
Graduate
Dry-matter intake during early phases of growth for subspecies of deer (Odocoileus hemionus)
Text