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Efficiency of protein utilization by growing chinchilla fed two levels of protein. Rogier, John Charles 1971

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EFFICIENCY OF PROTEIN UTILIZATION BY GROWING CHINCHILLA FED TWO LEVELS OF PROTEIN by JOHN CHARLES ROGIER B.Sc, University of British Columbia, 1965 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of Animal Science We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA October, 1971 In presenting t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r reference and study. I f u r t h e r agree that permission f o r extensive copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . I t i s understood that copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n permission. Department of /A /Vwwi J k The U n i v e r s i t y of B r i t i s h Columbia Vancouver 8, Canada Date i i i ABSTRACT Six male and six female chinchilla (Chinchilla lanigera) in the late phase of growth were used to study the effects of sex, crude protein level in the ration and duration of experiment on body weight gains, digestibility of energy, dry matter, organic matter and protein and efficiency of protein utilization, as measured by biological value and net protein utilization. Two isocaloric rations of differing crude protein content (16.25% and 19.56%) were supplied ad libitum for three one-week experi-mental periods. The results showed that female chinchilla had significantly (P<0.05) greater body weight gains than males after adjustment for i n i t i a l body weight and feed intake. There was a significant (P<0.05) effect of ration on the digestibility coefficients studied. The mean apparent digestibility coefficients for energy, dry matter, organic matter and protein for ration 1 (16.25% crude protein) were 65.09, 66.44, 67.73 and 62.83%, respectively; while for ration 2 (19.56% crude protein) the values were 67.32, 68.52, 70.21 and 73.23%, respectively. On the other hand, sex had no significant (P<0.05) effect on digestibility. There was a significant (P<0.05) effect of ration on the protein utilization indices studied. Biological value was not significantly (P<0.05) different for the two rations. The mean values for biological i v value and net protein u t i l i z a t i o n for ration 1 (16.25% crude protein) were 66.38 and 42.02%, respectively; while for ration 2 (19.56% crude protein) the values were 66.96 and 48.17%, respectively. On the other hand, sex had no significant (P<0.05) effect on protein u t i l i z a t i o n . The sensitivity of growing chinchilla to protein quality suggests a major role for prececal digestion and absorption although this does not preclude the synthesis and subsequent breakdown of microbial protein in the postcecal part of the gut. TABLE OF CONTENTS Page TITLE PAGE i ABSTRACT i i i TABLE OF CONTENTS v LIST OF TABLES v i i LIST OF FIGURES v i i i ACKNOWLEDGMENTS ix I. INTRODUCTION 1 II. LITERATURE REVIEW 2 A. The Animal: Chinchilla lanigera 2 1. General 2 2. Nutritional Physiology 2 B. Protein Utilization in the Whole Animal 4 1. Physiological State and Protein Reserves . . . 5 2. Caloric Intake 5 a. The Effects of Constant Protein Levels with Varying Energy Intake . 6 b. The Effects of Constant Energy Levels with Varying Protein Intake 6 c. The Effects of Carbohydrate and Fat on Protein Utilization 7 3. Essential Amino Acid and Total Nitrogen Intake 7 4. Amino Acid Imbalance 8 C. Methodology of Evaluation of Protein Utilization . 9 1. Weight Gain Method 9 2. Nitrogen Balance 10 vi Page III. EXPERIMENTAL 11 A. Object of Research . . . . . . . . . 11 B. Experimental Approach 11 C. Experimental Design 12 D. Materials 12 1. Animals 12 2. Housing 14 3. Rations 14 E. Methods 16 1. Data Collections 16 2. Chemical Analysis 17 3. Statistical Analysis 17 F. Calculations 19 1. Apparent Digestibility . . . . 19 2. Biological Value 20 3. Net Protein Utilization 21 G. Results and Discussion 21 1. Formulation and Chemical Composition of Rations 21 2. Body Weight Gains 21 3. Digestibility Coefficients 25 4. Biological Value, Net Protein Utilization . . 27 IV. CONCLUSIONS 32 V. BIBLIOGRAPHY . 33 VI. APPENDIX 39 v i i LIST OF TABLES Table Page 1 Design of Experiment 13 2 Formulation of Experimental Rations 22 3 Chemical Composition of Experimental Rations 23 4 Least Squares Means of Weekly Body Weight Gains Adjusted for Initial Body Weight and Type of Nutrient Intake 24 5 Least Squares Means of Digestibility Coefficients Adjusted for Nutrient Intake and Initial Body Weight 26 6 Least Squares Means of Protein Utilization Indices Adjusted for Protein Intake and Initial Body Weight 28 v i i i LIST OF FIGURES Figure Page 1 Photograph of a Digestibility Cage 15 ix ACKNOWLEDGMENTS During this study I became indebted to a number of people. Dr. R. M. Beames, Department of Animal Science, directed the project. Dr. W. D. Kitts, Department of Animal Science, provided financial support and allowed the use of the necessary facilities. Dr. R. C. Fitzsimmons, Department of Poultry Science, Dr. L. E. Lowe, Department of Soil Science, Drs. W. D. Kitts and C. R. Krishnamurti, Department of Animal Science, offered many help-ful suggestions during the preparation of the manuscript. Dr. R. G. Peterson and Mr. C. J. Williams of the Department of Animal Science assisted with the statistical analysis of the data. EFFICIENCY OF PROTEIN UTILIZATION BY GROWING CHINCHILLA FED TWO LEVELS OF PROTEIN I. INTRODUCTION Information on the biology of the chinchilla is scarce. To date, chinchilla research has been focussed on studies of metabolic rate (13), reproductive physiology (22) and the biochemistry of digestion (52). A few nutritional investigations have been reported (28, 31, 32). Nutritional requirements for maintenance, growth and repro-duction are unknown. At the present time i t is standard commercial practice to feed the same diet to a l l animals regardless of their stage in production. In particular, information on protein nutrition is lacking (32). The purpose of this study is to measure the efficiency of protein utilization and to establish the protein requirements of chinchilla in the late phase of growth. II. LITERATURE REVIEW A. The Animal: Chinchilla lanigera 1. General Chinchilla were introduced into North America about f i f t y years ago. Since then, there has been a rapid increase in their numbers due to their importance as a luxury fur animal. At present there are approximately 16,000 animals in British Columbia (17). Bickel (3) measured the growth curve of Chinchilla lanigera. The average weight of adult males on a ranch diet i s about 475 g, with females weighing approximately 50 g more (3, 28). Most animals reach mature weights at approximately nine to eleven months of age (53). 2. Nutritional Physiology The chinchilla i s a nonruminant herbivore with a large cecum. The role of the cecum as a possible site of fermentation, digestion and absorption in the chinchilla and other nonruminant herbivores, such as the rabbit and the horse, was, u n t i l recently, poorly defined. Smith (52) found that in chinchilla the main sites of cellulose break-down were the cecum and the large intestine. Although low levels of vo l a t i l e fatty acids were found in the stomach and small intestine, these have been attributed to coprophagy (52). It is generally assumed 3 that in the rabbit, feces-eating in conjunction with fermentation in the large intestine probably provides insurance against essential amino acid deficiency and may permit further digestion of fiber and other nutrients by a second passage through the digestive tract (54). To date, the importance of the cecum in the protein nutrition of the nonruminant herbivore has been studied only i n the horse (24, 44). Although some results suggest that the major si t e of protein digestion i s prececal they also demonstrate that there i s a significant amount of nitrogen absorbed from the lower gut. If the major s i t e of protein digestion i s the small intestine, the protein quality of the diet would be an important consideration for the growth of young foals. On the other hand, i f the major s i t e of protein digestion i s the cecum the quality of the dietary protein would be of less importance. The fact that mature rabbits (26), horses (24) and chinch i l l a (17, 25) have been maintained on low quality forages would indicate that the quality of dietary protein i s not of great importance for maintenance. Growing animals, however, are found to be more responsive to protein quality than adults because the amino acid requirements for growth are much greater than those for maintenance (43). For example, Hintz et a l . (23) found that young horses fed diets containing milk products, a good source of amino acids, grew much faster than animals fed diets containing poorer quality proteins. On the other hand, i t is possible that the maintenance requirements of amino acids i n the nonruminant herbivore can be met by bacterial synthesis followed by enzymatic degradation and absorption of amino acids in the lower gut (24,54). 4 Commercial chinchilla diets normally consist of pellets supple-mented with hay or alfalfa (25). The ingredients of the pellets are usually cereal grains, alfalfa and a source of good quality protein (25). Brickel (3) recommended the use of hay as a source of roughage in addition to pellets. This combination was reported to reduce the incidence of digestive upsets observed when only pelleted rations were fed. On the other hand, Farmer (14) reported that animals per-formed satisfactorily when fed pellets only. B. Protein Utilization in the Whole Animal Since there are no reports on work specifically designed to evaluate the utilization of protein by chinchilla, this topic will be discussed in terms of work done with other animals. The requirement for protein is not for protein as such, but for specific amounts and proportions of the essential and nonessential amino acids (43). The animal synthesizes proteins and other nitrogenous compounds from the amino acids. However, protein synthesis can take place only i f energy needs are met; i f they are not, dietary protein is used to meet the primary need of the body which is for energy. The technique most commonly employed to evaluate specific amino acid and total nitrogen requirements is the nitrogen balance (43). Several interacting factors affect the interpretation of nitrogen balance data. Among the most important of these factors are physiological state, protein reserves, caloric value of the diet and the levels of essential and nonessential amino acids in the diet. 5 1. Physiological State and Protein Reserves A positive nitrogen balance is characteristic of a growing animal. It is an indication of the degree of protein synthesis occurring in the animal (11). Increased nitrogen retention is also exhibited during protein repletion of animals depleted of labile protein (56). In this latter case, the extent of positive balance reflects the extent of protein depletion (1). In the case of animals in a negative nitrogen balance the reverse pattern is exhibited. 2. Caloric Intake The effect of caloric intake on nitrogen balance has been widely reported (1). If energy intake is reduced below a critical level, caloric intake rather than nitrogen intake becomes the limiting factor in nitrogen balance. The utilization of protein for energy purposes is indicated by an increased nitrogen excretion (58). This means that the primary function of protein, which is , tissue synthesis, can take place only i f the energy needs of the animal are met. Conversely, i f nitrogen excretion is reduced when energy intake is increased then protein previously used to meet energy requirements is now used for protein synthesis (40). Several workers have studied the relationship between protein utilization and energy intake in rats and man (4, 5, 7, 8, 9). The effects of constant protein levels with varying energy intake and the effects of constant energy levels with varying protein intake were investigated, as well as the effects of carbohydrate and fat on protein utilization. 6 (a) The Effects of Constant Protein Levels with Varying Energy Intake  As caloric intake increases, with protein intake held constant, protein utilization as measured by carcass analysis increases to a maximum, beyond which no additional protein utilization occurs (7). On the other hand,animals restricted in energy intake below the mainten-ance level f a l l into a negative nitrogen balance. The extent of the negative balance is related to the degree of caloric restriction (9). Any increase in nitrogen excretion on an energy-deficient diet is the result of the breakdown of dietary and labile protein to meet energy demands. If the degree of caloric restriction is limited, the in i t i a l loss of body nitrogen will diminish indicating an adaptation to caloric restriction through a reduction of metabolic activity (38). For example, Bosshardt (4) found that in growing rats a 34% decrease in energy intake resulted in a 14% decrease in energy expenditure. It would appear that an animal can regulate nitrogen balance by adjusting metabolism. (b) The Effects of Constant Energy Levels with Varying Protein Intake  As protein intake increases with caloric intake held constant, protein utilization increases to a maximum rate after which the rise becomes progressively smaller (43). The rate of decrease is character-ist i c for each protein (38). Calloway and Spector (9) have shown that the nitrogen utilization in rats diminished from approximately 55% to 17% when the level of dietary nitrogen increased from 75 mg to 604 mg daily. 7 (c) The Effects of Carbohydrate and Fat on Protein U t i l i z a t i o n Carbohydrate has an effect on protein u t i l i z a t i o n which is distinct from i t s calorigenic function (43). It has a protein-sparing effect which cannot be taken by fat. In diets adequate i n protein and energy, the replacement of carbohydrate calories by fat calories results in an increase in nitrogen excretion (55). Thomson and Munro (55) suggest that this i s due to the removal of carbohydrate rather than to an adverse effect of feeding fat with the protein. According to Munro, evt _al. (39), the mechanism through which carbohydrate has an effect on protein u t i l i z a t i o n may be related to the fact that carbohydrate, but not fat, i s responsible for a temporary drop in plasma amino acids with the amino acids being deposited in muscle. They suggested that the agent causing the s h i f t of amino acids into muscle is insulin, whether the insulin has a protein-sparing effect by increasing the permeability of the muscle c e l l membrane to amino acids or whether the hormone has an effect on polypeptide syn-thesis within the c e l l has not been elucidated (33). 3. Essential Amino Acid and Total Nitrogen Intake If energy and other nutrient intakes are adequate, nitrogen balance i s dependent primarily on (43): (i) the amounts and proportions of essential amino acids supplied by the diet, and ( i i ) the total nitrogen intake. The interrelationship between amino acid composition of the diet and 8 total nitrogen intake was i l l u s t r a t e d in early studies by Sherman (50). He showed that replacement of 10% of the protein in a cereal diet by milk resulted in a marked decrease in the total nitrogen requirement necessary to maintain nitrogen equilibrium. Evidence of the importance of amino acid composition, expressed as biological value, on the total protein requirement was also presented by Bricker (6). The requirement for the essential amino acids i s generally considered the main factor in the determination of protein requirement (6). It i s becoming increasingly obvious that nonessential amino acids also play an important role. Several studies (50, 53) suggest that the relative proportions of essential and nonessential amino acids i n the diet are more important than has been supposed. 4. Amino Acid Imbalance In protein nutrition i t i s important to distinguish between amino acid deficiency and amino acid imbalance. Amino acid deficiency refers to a protein of low biological value which can be improved by the addition of one or more of the limiting amino acids. On the other hand, amino acid imbalance (20) refers to an already deficient protein which i s made even more deficient by the addition of one or more amino acids. The significance of amino acid imbalance i n protein nutrition i s somewhat vague (43). It seems possible that supplementing an already poor protein with certain amino acids or proteins could have detrimental effects. The effects of feeding a combination of low quality proteins, as is the case in many human and animal diets, require further investigation. 9 C. Methodology of the Evaluation of Protein Utilization The relative usefulness of the protein of a particular feed in meeting the animal's protein needs is often referred to as its quality (12). Methods for the evaluation of protein quality in foods have been reviewed frequently (37, 40). It is generally accepted that biological evaluation, as distinct from chemical and microbiological evaluation, is the most reliable method for determining protein quality since i t is the ability of a protein to support maintenance and growth that determines its ultimate value (43). Many methods are available for the biological evaluation of proteins. No attempt will be made to discuss a l l methods which have been reported. This review will be concerned with some of the more common methods for assessing the efficiency of protein utilization (10, 35, 43). 1. Weight Gain Method The rate of growth of an animal under defined conditions provides a relatively simple way of measuring the value of dietary protein (43). If the diet contains insufficient amounts of one or more of the essential amino acids or i f i t is lacking in total nitrogen, growth will be severely reduced. Thus growth is a sensitive index of the amount and proportions of amino acids assuming that a l l other nutrients are adequately supplied. Although the weight gain method or feeding t r i a l requires a relatively long period of time and provides l i t t l e information on the metabolism of 10 protein (10), i t is s t i l l the most useful way of obtaining results which have a direct application to feeding practice (34). 2. Nitrogen Balance A determination of the nitrogen in the food and excreta under controlled conditions provides a quantitative measure of the protein metabolism and specifically shows whether the body is gaining or losing protein (34). A nitrogen-balance experiment involves a record of nitrogen consumed and nitrogen voided in the feces and urine. The nitrogen-balance method is used to determine the protein requirements for various body functions and to study the efficiency of protein utilization by the animal. The results of the nitrogen balance are used to calculate nutri-tional indices that provide a measure of protein utilization. The more commonly used indices are biological value and net protein utilization (43, 35). Biological value is a measure of nitrogen retained for growth or maintenance and is expressed as nitrogen retained divided by nitro-gen absorbed (36). Net protein utilization is a measure of both the digestibility of the food protein and the biological value of the amino acid mixture absorbed from food (43). Net protein utilization represents the proportion of food nitrogen retained, whereas biological value represents the proportion of absorbed nitrogen retained. III. EXPERIMENTAL A. Object of Research The efficiency of utilization of dietary protein in nonruminant herbivores depends on the site of protein digestion and absorption (23, 46). If the protein is digested and absorbed in the small intes-tine, the protein quality of the diet would be as important for the growth of the chinchilla as any other monogast. On the other hand, i f a significant amount of nitrogen reaches the cecum and is subjected to the degradative and synthetic action of cecal microorganisms the in-gested nitrogen can be converted into microbial protein prior to possible proteolytic digestion in the lower gut (45). In that case the chinchilla would be similar to the ruminant and not dependent on the diet for essential amino acids. The object of this research is to measure the efficiency of protein utilization and to establish the protein requirements of chin-chilla in the late phase of growth. B. Experimental Approach Practical feeding experiments and nitrogen balance studies are common methods for assessing the efficiency of protein utilization (10, 12 35, 43). In this study a feeding t r i a l was run during which digesti-bili t y and nitrogen balance measurements were taken on male and female chinchilla in the late phase of growth. To investigate the suitability of the rations and other experimental conditions the experiment was conducted over three consecutive one-week periods. C. Experimental Design The experiment was designed as a 2 x 2 x 3 factorial. The effects of sex, two levels of crude protein (16.25% and 19.56%) and time (3 consecutive one-week experimental periods) on protein utiliza-tion in chinchilla during the late phase of growth were investigated. Three individually-caged animals were allocated per treatment. The treatments are described in Table 1. The following performance traits were calculated and analyzed by the least squares method of Harvey (21): body weight gains, digesti-b i l i t y coefficients (energy, dry matter, organic matter and protein), biological value and net protein utilization. D. Materials 1. Animals The animals used were Chinchilla lanigera born and raised at The University of British Columbia Chinchilla Unit. Twelve young adult chinchilla with mean body weight of 460 g at start of feeding were Table 1 Design of Experiment Treatments^ Sex Rations Periods Female 16.25% protein Week 1 II II Week 2 II II Week 3 Female 19.56% protein Week 1 ti II Week 2 ti II Week 3 Male 16.25% protein Week 1 it it Week 2 ii II Week 3 Male 19.56% protein Week 1 II II Week 2 II it Week 3 Three individually-caged animals per treatment 14 randomly assigned to two rations with three males and three females per ration. A l l animals were between 6 and 8 months of age and kept under the same conditions of feeding and housing prior to experimenta-tion. A l l animals were in good health throughout the experimental period. The experiment proper was started after a ten day acclimation period during which time the animals became accustomed to routine experimental procedures. 2. Housing Animals were randomly and individually allocated to galvanized wire mesh cages (15" x 18" x 12") with 1/2" mesh spacing. A l l cages were equipped with a stainless steel urine-feces collecting funnel. An extra fine (6 mesh per cm) wire screen was placed on top of the funnel to ensure the separation of feces and urine. A photograph of one of the digestibility cages is shown in Figure 1. A dustbath, con-sisting of pulverized rock, was provided twice a week for fur-cleansing purposes. Small blocks of f i r for gnawing and fresh drinking water were available at a l l times. The animals were kept at The University of British Columbia Chinchilla Unit in a temperature-controlled room (20°C ± 1°C) and in natural illumination. 3. Rations The experimental rations were fed in pelleted form ad libitum. The two rations were isocaloric but of differing crude protein content. The control ration consisted of a commercial chinchilla feed Figure 1 Photograph of a d i g e s t i b i l i t y cage 16 (National Feeds Ltd., Abbotsford, British Columbia) which was ground and repelleted. The other ration was formulated by replacing one-tenth of the control ration with fat-extracted soybean meal (48.5% protein). Soybean meal was used as the protein supplement because i t is an excellent source of amino acids for nonruminants herbivores (23). The composition and proximate analysis of the test rations are given in Table 2 and Table 3, respectively. Water was supplied ad libitum. E. Methods 1. Data Collections (a) Body Weights Al l animals were weighed at the beginning and end of each of the three one-week experimental periods. (b) Feed Intake Individual food consumption was measured every day and totalled for each week. No appreciable food wastage occurred. (c) Feces Feces were collected daily from the fine wire screen described in the section on housing, air dried, and stored at room temperature. The weekly output was pooled for each animal.' (d) Urine Urine was collected under a toluene layer (3 drops per 250 ml erlenmeyer flask) to prevent interaction between the urine and the 17 atmosphere). Sulphuric acid (1 ml of 50% H^ SO^ ) was added to the collection flask as a preservative. Daily collections were stored in a freezer (-11°C) and the weekly output was pooled for each animal. 2. Chemical Analysis (a) Dry Matter Feed and fecal dry matter were determined on samples of air-dry material which were ground and mixed prior to drying at 85-90°C to a constant weight. (b) Gross Energy Gross energy values of feed and feces were obtained by combustion in a Gallenkamp^" adiabatic oxygen bomb calorimeter (18). (c) Crude Protein Crude protein content determinations were made on feed, feces and urine samples using the official A.O.A.C. procedure (2). Nitrogen content was converted to crude protein by multiplying by 6.25 (34). (d) Ash Ash determinations were done on oven dry feed and feces by dry ashing samples according to the official A.O.A.C. procedure (2). 3. Statistical Analysis A least squares analysis developed by Harvey (21) was used to estimate the effects of sex, ration and time and a l l interactions on the performance traits mentioned earlier (see III. C. Experimental Design). Gallenkamp, London, E.C. 2. 18 Initial body weight and feed intake were used as covariables to adjust performance traits studied for differences due to these factors. The linear mathematical model assumed was: Y i j k l = ° + S i + r j + \ + ( s r > i j + ( 8 t ) i k + ( r t ) j k + ( 8 r t ) i j k + where: J :k i j jk b B i j k l + f F i j k l + e i j k l ' Y . , = The observed value of the various performance traits under i j k l study of the l*" * 1 animal of the i*"* 1 sex on the j*"*1 ration til during the k week of the experiment, a = The population mean for the trait under study. til s. = The effect of the i sex. x th r. = The effect of the j ration. t, = The effect of the k*"*1 week. til til (sr).. = The joint effect of the i sex on the j ration when the effects of sex and ration are held constant. (st)_j^ = The joint effect of the i t b sex during the k ^ week when the effects of sex and time are held constant. (rt)., = The joint effect of the j f c ^ ration during the k*"** week when the effects of ration and time are held constant. til til (srt) . = The joint effect of the i sex on the j ration during the k ^ week when the effects of sex, ration and time are held constant. = The partial regression coefficient of Y. ., . on B. ., ,. i j k l i j k l 19 th B . - = The i n i t i a l body weight associated with the 1 animal of i j k l the i*"* 1 sex on the j 1"* 1 ration during the k*"*1 month. f = The partial regression coefficient of ^ ^jj.-^ o n F,.., = The feed intake associated with the l* " * 1 animal of the i* " * 1 i j k l sex on the j*"*1 ration during the k ^ month. e.., - = The random effect associated with the l ' * 1 animal of the i j k l i* " * 1 sex on the j " 1 ration during the week, which is assumed to be independent and normally distributed with mean equal zero and variance a^. All effects in the model except were regarded as fixed. The level of significance was 0.05. All significant effects were tested by Duncan's new multiple range test, as modified by Kramer (30). F. Calculations 1. Apparent Digestibility The apparent digestion of energy, dry matter, organic matter and protein was calculated as the difference between nutrient intake and feces excretion, expressed as a per cent of nutrient intake. Since no corrections were made for fecal components of endogenous origin, i t was assumed that the feces represented residues of dietary origin only, and thus the term apparent digestibility would describe a l l such coefficients calculated in this experiment. The following formula was used to calcu-late digestibility: 20 % Digestibility _ (F o x Ao) - (F x x A l ) x 100 F x A o o where, F o grams of feed consumed. A o per cent "nutrient" content of feed: energy, dry matter, organic matter or protein. F 1 grams of feces excreted. per cent "nutrient" content of feces: energy, dry matter, organic matter or protein. 2. Biological Value Biological value (BV) is a measure of dietary nitrogen retained for growth or maintenance and is expressed as nitrogen retained divided by nitrogen absorbed. Such data can be obtained from a nitrogen balance experiment. The calculation is as follows: and is called the Thomas equation for apparent biological value (43). The Thomas equation was later modified by Mitchell (36) to correct for metabolic fecal losses and endogenous urinary losses. Since both of these fractions are difficult to measure this latter method was not used. 3. Net Protein Utilization Since the overall usefulness of a given source of protein depends on its digestibility as well as on the biological value of the N Intake - (Fecal N + Urinary N) N Intake - Fecal N x 100 = Biological Value 21 absorbed fraction, net protein utilization is expressed as follows (34): Net Protein Utilization = Biological Value x Protein Digestibility Net protein utilization (NPU) represents the proportion of food nitrogen retained, whereas biological value represents the proportion of absorbed nitrogen retained (43). Since apparent digestibility and apparent biological value were used only apparent net protein utilization values are reported. G. Results and Discussion 1. Formulation and Chemical Composition of Rations The ingredients of the test rations are given in Table 2. The average chemical compositions of the test rations are presented in Table 3. Both rations are essentially isocaloric with gross energy values of about 4.45 kcal/g. The crude protein content of ration 1 and ration 2 was 16.25 and 19.56%, respectively. The ash content of ration 1 was higher (9.4%) than that of ration 2 (8.9%). All analyses were performed on oven-dried material. Both rations contained 89.9% dry matter. 2. Body Weight Gains Body weight gains were analyzed and the least squares means for the main effects presented in Table 4. A record of i n i t i a l and final body weights and body weight gains is shown in Appendix Table I. 22 Table 2 Formulation of Experimental Rations Ingredients Ration 1 (16.25% crude protein) Ration 2 (19.56% crude protein) Ground wheat % 15.0 % 13.5 Ground corn 5.0 4.5 Ground barley 5.0 4.5 Soybean meal (48.5% crude protein) 13.5 22.1 Sun-cured alfalfa 30.0 27.0 Ground beet pulp 5.0 4.5 Distiller's solubles 10.0 9.0 Defluorinated phosphate 2.5 2.25 Dried whey 0.8 0.75 Iodized salt 0.5 0.45 Molasses 10.0 9.0 Durabond"'" 2.5 2.25 Vitamin-mineral-anti-biotic premix^ 0.25 0.25 Durabond is a commercial lignin sulphate product which has the ability to "harden" the pellets. It is manufactured by Georgia-Pacific Co. Ltd., Bellingham, Washington. 'Contributed the following amounts of vitamins, minerals and antibiotics per kg. of complete diet: vitamin A, 4410 I.U.; vitamin D3, 1100 I.U.; vitamin E, 5.5 I.U.; riboflavin 4.4 mg.; calcium pantothenate 8.8 mg.; niacin, 19.8 mg.; vitamin B12, 6.6 meg.; choline chloride, 250 mg.; D-L methionine, 610 mg.; vitamin K, 1 mg.; oleandomycin, 2 mg.; zinc oxide, 66 mg.; potassium iodide, 0.5 mg.; manganese oxide, 88 mg. 23 Table 3 Chemical Composition of Experimental Rations Ration 1 (16.25% crude protein) Ration 2 (19.56% crude protein) Mean ± S.D. Mean ± S.D. Gross Energy (kcal/g) 4.45 ± .05 4.44 ± .03 % Crude Protein 16.25 ± .07 19.56 ± .08 % Ash 9.40 ± .02 8.90 ± .06 Al l values are means of triplicate determinations. 24 Table 4 Least Squares Means of Weekly Body Weight Gains Adjusted for Initial Body Weight and Type of Nutrient Intake Comparison Type of Nutrient Intake Groups Energy (g) Dry Matter (g) Organic Matter (g) Protein (g) Female 13.l a 13.0a 12. 7 a 13. l a Male 1.5b - 0.6b - 0.2b 0.9b Ration 1 (16.25% crude protein) 8.6a 8.5a 8.4a 10.6a Ration 2 (19.56% crude protein) 6.0a 4.1a 4.1a 5.3a Week 1 6.3a 4.2a 2.7a 3.5a Week 2 2.3a 2.4a 2.9a 2.0a Week 3 13.3a 12.5a 13.13 13. l a Mean Initial Body Weight (g) 456 456 456 456 Mean Nutrient Intake (g/week) 6451 144.5 125.5 25.84 Within comparison groups, values not having a common superscript are significantly different (P<0.05). Given in kcal/week. 25 Individual nutrient intakes of energy, dry matter, organic matter and protein are given in Appendix Table II. Sex was a significant source of variation on body weight gains. Females had better gains and better feed utilization than males. Whether this finding can be attributed to greater rate of gains in females or earlier mature weights in males is not known. Rations and time were not significant effects; also, none of the interactions was significant. The effects of the two covariables, i n i t i a l body weight and feed intake, were a significant source of variation. 3. Digestibility Coefficients Table 5 summarizes the results of the least squares analyses on the apparent digestibilities of energy, dry matter, organic matter and protein. A complete record of the derivation of the four categories of digestibility coefficients is presented in Appendix Tables III, IV, V and VI, respectively. The females had significantly greater apparent digestibilities of energy, dry matter and organic matter than the males. Although there was no significant effect of sex on apparent protein digestibility, females tended to have higher values than males. The greater apparent digestibility of energy by the females may have contributed to greater gains in the feeding t r i a l . Rations were a significant source of variation. Ration 2 (19.56% crude protein) was more digestible than ration 1 (16.25% crude protein) for a l l four digestibility coefficients. However, there was no signifi-cant effect of ration on body weight gains. It could be that the greater 26 Table 5 Least Squares Means of Digestibility Coefficients Adjusted for Nutrient Intake and Initial Body Weight Digestibility Coefficients Comparison Groups Apparent Digestible Energy (%) Apparent Digestible Dry Matter (%) Apparent Digestible Organic Matter (%) Apparent Digestible Protein (%) Female 67.803 69.013 70.793 69.163 Male 64.46b 65.95b 67.15b 66.903 Ration 1 (16/25% crude protein) 65.093 66.44a 67.73a 62.83a Ration 2 (19.56% crude protein) 67.32b 68.52b 70.21b 73.23b Week 1 68.71° 67.18C 69.95C 69.80C Week 2 65.43° 70.18C 71.24C 72.14C Week 3 64.26C 65.08d 65.72d 62.16d Within the sex and ration comparison groups, values not having a common superscript are significantly different (P<0.05). ^Within the period comparison group, values not having a common superscript are significantly different (P<0.05) from each other by Duncan's new multiple range test as modified by Kramer (30). 27 digestibility of ration 2 was not large enough to result in significantly greater body weight gains. Time was also a significant source of variation for a l l digesti-bi l i t y coefficients except apparent digestible energy. During the third week of the experiment the apparent digestibility of dry matter, organic matter and protein was significantly lower than for the first and second weeks. A similar trend was observed for the apparent digestibility of energy. However, the drop in digestibility during the third week had no significant effect on body weight gains. None of the interactions had a significant effect on digestibi-l i t y . The two covariables, i n i t i a l body weight and feed intake, had no significant effect on the digestibility coefficients studied. A comparison between the apparent digestibility of energy and dry matter indicated that, as is the case with cattle and sheep (19), these values are very close. Therefore, a reliable estimate of apparent digestible energy can be obtained from apparent digestible dry matter. Bomb calorimetry of feces should thus seldom be necessary. 4. Biological Value and Net Protein Utilization A summary of the least squares means of the nutritional indices derived from the nitrogen balance is shown in Table 6. Least squares means for the main effects are listed for biological value and net protein utilization. A complete record of input and output parameters of the nitrogen balance is given in Appendix Table VII. 28 Table 6 Least Squares Means of Protein Utilization Indices Adjusted for Protein Intake and Initial Body Weight Protein Utilization Indices Comparison Groups Biological Value (%) Net Protein Utilization (%) Female 68.403 46.90a Male 64.94a 43.28a Ration 1 (16.25% crude protein) 66.38a 42.02a Ration 2 (19.56% crude protein) 66.96a 48.17b Week 1 67.24C 46.08C Week 2 67.38c 48.53C Week 3 65.39d 40.67d Within the sex and ration comparison groups, values not having a common superscript are significantly different (P<0.05). ^Within the periods comparison group, values not having a common superscript are significantly different (P<0.05) from each other by Duncan's new multiple range test as modified by Kramer (30). 29 Sex was not a significant source of variation for any of the two protein utilization indices studied. Consequently better protein utilization by females did not account for their greater body weight gains. However, better feed utilization, as indicated by greater apparent digestibility of energy, dry matter and organic matter, con-tributed towards the larger gains by females. Ration 2 (19.56% crude protein) showed a significantly greater net protein utilization than ration 1 (16.25% crude protein). Differ-ences in biological value for rations were not significant; however, ration 2 tended to have a greater biological value than ration 1. This would mean that the animals utilized efficiently supplemental protein of high quality. Time was a significant source of variation for both protein utilization indices studied. During the third week of the experiment there was a decrease in the utilization of the protein. The lower values for the digestibility coefficients and protein utilization indices were, however, not large enough to result in any significant decrease in body weight gains. It is possible that during repelleting, the experimental rations became deficient in one or more essential nutrients and that this deficiency only became manifest during the third week of the experiment. Another possible explanation is the absence of unpelleted hay or alfalfa from the ration. However, no signs of digestive upsets were observed throughout the experiment. The effect of a source of roughage on the physiology of the digestive system remains to be investigated. 30 None of the interactions had a significant effect on protein utilization. The two covariables, i n i t i a l body weight and protein intake, had no significant effect on the protein utilization indices studied. Although i t has been suggested that the large intestine is the main site of digestion and absorption in the horse (29), rabbit (26) and, possibly, chinchilla (52), information concerning the relative importance of different segments of the digestive tract in protein nutrition is not available. Recent studies by Reitnour et al. (44) and Hintz et_ al. (24) indicated that in the equine the major site of protein digestion is prececal although there is a significant disappear-ance of nitrogen from the lower gut. According to Hintz jet al. (23) the site of digestion of a component of the feed was not influenced by the diet. For instance, they found that the major site of fibre digestion was the cecum and colon whereas the major site of available carbohydrate and protein digestion was prececal regardless of the hay : grain ratio. These results suggest a major role of prececal protein digestion and absorption in the equine, and i t appears that protein digestion and absorption in this species more closely resemble those functions reported for the chick (46) and the pig (47) than for cattle (41). The results of the protein utilization study suggest that the animals on the higher protein ration utilized the protein more efficiently than the animals on the lower protein ration. This could be attributed to a greater utilization of the higher quality protein supplement over 31 the lower quality protein of the basal ration. The sensitivity of the growing chinchilla to protein quality suggests a major role for prececal protein digestion and absorption although this does not necessarily preclude the synthesis of microbial protein in the lower gut. Identification of digestive products and quantification of their absorption is needed before the contribution of different parts of the alimentary canal to the protein nutrition of the chinchilla can be fully evaluated. 32 IV. CONCLUSIONS Female chinchilla utilized feeds more efficiently than male chinchilla during the late phase of growth as indicated by greater body weight gains for females after adjustment for i n i t i a l body weight and feed intake. These gains were not the result of better protein utilization but of a better energy utilization. The growing chinchilla utilized the protein in the 19.56% crude protein ration approximately 9% more efficiently than in the 16.25% crude protein ration. The efficient utilization of high quality protein suggests a considerable amount of prececal digestion and absorption. Apparent digestible dry matter is a reliable estimate of apparent digestible energy. A decrease in protein utilization occurred during the third week of the experiment. However, this decrease did not result in a reduction in body weight gains. BIBLIOGRAPHY 34 Bibliography 1. Allison, J. B. (1957). Interpretation of nitrogen balance data. Fed. Proc. 10: 676. 2. A.O.A.C. (1965). Official Methods of Analysis (10th ed.). Association of Official Agricultural Chemists, Washington, D.C. 3. Bickel, E. (1962). (The subject of chinchilla feeding) Deutsch. Peltzterzuchter. 36: 66. 4. Bosshardt, D. K., W. Paul, K. O'Doherty and R. H. Barnes (1946). The influence of caloric intake on the growth utilization of dietary protein. J. Nutr. 32: 641-652. 5. (1948). Caloric restriction and protein metabolism in the growing mouse. _J. Nutr. 36: 773-783. 6. Bricker, M., H. H. Mitchell, and G. M. Kinsman (1945). The protein requirements of adult human subjects in terms of the protein contained in individual foods and food combinations. <J. Nutr. 39: 455-461. 7. Benditt, E. P., E. M. Humphreys, R. W. Wissler, C. H. Steffee, L. E. Frazier, and P. R. Cannon (1948). The dynamics of protein metabolism. I. The interrelationship between protein and caloric intakes and their influence upon the utilization of ingested protein for tissue synthesis by the adult protein-depleted rat. J_. Lab. Clin. Med. 33: 257-268. 8. , R. L. Woolridge, and R. Stepto (1948). The dynamics of protein metabolism. II. The relationship between the level of protein intake and the rate of protein utiliza-tion by protein-depleted man and rats. J^ . Lab. Clin. Med. 33: 269-279. 9. Calloway, D. H. and H. Spector (1954). Nitrogen balance as related to caloric and protein intake in active young men. Amer. J. Clin. Nutr. 2: 405-412. 35 10. Conrad, H. R., J. W. Hibbs and A. D. Pratt (1960). Nitrogen metabolism in dairy cattle. I. Efficiency of nitrogen utilization by lactating cows fed various forages. U.S.D.A. Research Bulletin 861. 11. Coons, C. M., and G. B. Marshall (1934). Some factors affecting nitrogen economy during pregnancy. J_. Nutr. 7: 67-68. 12. Crampton, E. W. and L. E. Harris (1969). Applied animal nutri-tion. 2nd ed. W. H. Freeman and Company, San Francisco, p. 88. 13. Drozdz, A. and A. Gorecki (1967). Oxygen consumption and heat production in chinchillas. Acta Theriologica 12: 81-86. 14. Farmer, F. S. (1957). A study of protein in the diet of chinchilla. Fur Trade J. Can. 35: 35. 15. Food and Nutrition Board (1963). Natl. Acad. Sci. - Natl. Res. Council Publ. 843. 16. Fries, J. A., W. W. Braman, and M. Kriss (1924). On the protein requirement of milk production. J_. Dairy Sci. 7: 12. 17. The Fur Farm Industry in B. C. (1967). Province of B.C. Dept. Agric. Livestock Branch publ. 18. Gallenkamp and Co. Ltd. Oxygen bomb calorimetry and combustion methods. Technical Manual. Gallenkamp and Co. Ltd., London, E.C. 2. 19. Graham, N. McC. (1969). Relation between metabolizable and digestible energy in sheep and cattle. Aust. J_. Agric. Res. 20: 1117-1122. 20. Harper, A. E., P. Leung, A. Yoshida and Q. R. Rogers (1964). Some new thoughts on amino acid imbalance. Fed. Proc. 23: 1087-1092. 21. Harvey, W. R. (1960). Least squares analysis of data with unequal subclass numbers. ARS-20-8 U.S.D.A. Beltsville, Maryland. 22. Hilleman, H. H., F. D. Tibbitts and A. I. Gaynor (1959). Repro-ductive biology in chinchilla. NCBA Research Bulletin No. 1. Middletown, New York. 23. Hintz, H. F., D. E. Lowe and H. F. Schryver (1969),. Protein sources for horses. Proc. Cornell Nutr. Conf. p. 65. 36 24. Hintz, H. F., D. E. Lowe, H. F. Schryver, D. E. Hogue, and E. F. Walker Jr. (1971). Apparent digestion in various segments of the digestive tract of ponies fed diets with varying roughage-grain ratios. _J. An. Sci. 32: 245-248. 25. Houston, J. W. and J. P. Prestwich (1962). Chinchilla care, 4th ed., Borden Publ. Co. 26. Huang, T. C, H. E. Ulrich and C. M. McCay (1954). Antibiotics, growth, food utilization and the use of chromic oxide in studies with rabbits. J^ . Nutr. 54: 621. 27. Kidwell, J. F. (1955). Heritability of body weight in the chinchilla. J_. Heredity 46: 251-2. 28. King, K. W. and F. S. Orcutt (1952). Nutritional studies of the chinchilla with special reference to ascorbic acid and thiamine. J_. Nutr. 48: 31. 29. Kolb, E. and G. Wujanz (1958). Uber das vorkommen und die verteiling der sauren und alkalischen phosphatase in der schleinhaut verschiedener abschnitte des magendarm-kanals beim pferd. Zbl. Vet. Med. 6: 118. 30. Kramer, C. Y. (1957). Extension of multiple range tests to group correlated adjusted means. Biometrics 13: 13-18. 31. Larrivee, C. P. and C. A. Elvehjem (1954). Studies on the nutritional requirements of chinchilla. J_. Nutr. 52: 427. 32. Leoschke, W. L. and C. A. Elvehjem (1959). Riboflavin in the nutrition of the chinchilla. J_. Nutr. 69: 214. 33. Manchester, K. L. and F. G. Young (1961). Insulin and protein metabolism. Vitamins and Hormones 19: 95-132. 34. Maynard, L. A. and J. K. Loosli (1962). Animal Nutrition, 5th ed. McGraw-Hill, Toronto, p. 283. 35. McLaughlan, J. M., and J. A. Campbell (1969). Methodology of protein evaluation. In Mammalian Protein Metabolism, Vol. I l l , pp. 391-422, H. N. Munro and J. B. Allison, eds. Academic Press, New York, 1969. 36. Mitchell, H. H. (1924). A method of determining the biological value of protein. >J. Biol. Chem. 58: 873-903. 37. Morrison, A. B. (1964). In Symposium on Foods: Proteins and their Reactions. (H. W. Schultz and A. E. Angelmier, eds.). p. 361. Avi Publ., Westpost, Connecticut. 37 38. Morrison, A.B. and M. N. Rao (1967). Some relationships between proteins and calories. World Rev. Nutr. Diet. 7: 204. 39. Munro, H. N., J. G. Black, and W. S. T. Thomson (1959). The mode of action of dietary carbohydrate on protein metabolism. Brit. J. Nutr. 13: 475-485. 40. Munro, H. N. (1964). General aspects of the regulation of protein metabolism by diet and by hormones. In Mammalian Protein Metabolism. Vol. I, pp. 381-481, H. N. Munro and J. B. Allison, eds. Academic Press, New York. 41. Oltjen, R. R., A. S. Kozak, P. A. Putman and R. P. Lehmann (1967). Metabolism, plasma amino acid and salivary studies with steers fed corn, wheat, barley and milo all-concentrate rations. J_. Anim. Sci. 26: 1415. 42. Osborne, T. B. and L. B. Mendel (1917). The use of soybean as food. J. Biol. Chem. 32: 369-387. 43. Pike, R. L. and M. L. Brown (1967). Nutrition: An integrated approach. John Wiley & Sons, New York. 44. Reitnour, C. M., J. P. Baker, C. E. Mitchell Jr. and C. 0. Little (1969). Nitrogen digestion in different segments of the equine digestive tract. J^ . An. Sci. 29: 332-334. 45. Reitnour, C. M., J. P. Baker, G.E. Mitchell Jr., C. 0. Little and D. D. Kratzen (1970). Amino acids in equine cecal contents, cecal bacteria and serum. J_. Nutr. 100: 349. 46. Richardson, L. R., L. G. Blaylock and C. M. Lyman (1953). Influence of dietary amino acid supplements on the free amino acids in the blood plasma of chicks. J^ . Nutr. 51: 515. 47. Richardson, L. R., F. Hale and S. J. Ritchey (1965). Effect of fasting and levels of dietary protein on free amino acids in pig plasma. J_. Anim. Sci. 24: 368. 48. Rose, W.C. (1938). The nutritive significance of the amino acids. Physiol. Rev. 18: 109-138. 49. Scrimshaw, N.S., V. R. Young, R. Schwartz, M. Piche, and J.B. Das (1966). Minimum dietary essential amino acid-to-total nitrogen ratio for whole egg protein fed to young men. J. Nutr. 89: 9-16. 3 8 50. Sherman, H. C. (1920). Protein requirement of maintenance in man and the nutritive efficiency of bread protein. J. Biol. Chem. 41: 97-109. 51. Slade, L. M., D. W. Robinson, and K. E. Casey (1970). Nitrogen metabolism in nonruminant herbivores. I. The influence of nonprotein nitrogen and protein quality on the nitrogen rentention of adult mares. J_. Ariim. Sci. 30: 753-760. 52. Smith, D.C. (1970). Carbohydrate digestion in the chinchilla. M. Sc. Thesis, The University of British Columbia. 53. Stucki, W. P. and A. E. Harper (1962). Effects of altering the ratio of indispensible to dispensible amino acids in diets for rats. J. Nutr. 78: 278-286. 54. Thompson, H. W., and A. N. Worden (1956). The Rabbit. Wellmer Bros, and Co. Ltd., London and Glasgow, pp. 26-31. 55. Thompson, W. S. T. and H. N. Munro (1955). The relationship of carbohydrate metabolism to protein metabolism. IV. The effect of substituting fat for dietary carbohydrate. J. Nutr. 56: 139-150. 56. Whipple, C. H. (1948). Hemoglobin, plasma protein and cell protein. Charles C. Thomas, Springfield, 111. 57. White, M. C. (1964). Chinchilla Research. A bibliography. NCBA Research Bulletin No. 41, Middletown, New York. 58. Young, C. M., E. L. Empey, V. U. Serraon, and Z. H. Pierce (1957). Weight reduction in obese young men. Metabolic studies. J. Nutr. 61: 437. VI. APPENDIX TABLE I Initial and Final Body Weights TREATMENTS Animal No. Week 1 Week 2 Week 3 Sex Ration Initial Weight (g) Final Weight (g) Weight Gain (g) Initial Weight (g) Final Weight (g) Weight Gain (g) Initial Weight (g) Final Weight (g) Weight Gain (g) 1 464 452 -12 452 470 18 470 482 12 16.25% crude protein 2 454 460 6 460 467 7 467 464 - 3 Female 3 443 476 33 476 470 - 6 470 484 14 4 468 495 27 495 497 2 497 504 7 19.56% crude protein 5 549 556 7 556 542 -14 542 545 3 6 468 464 - 4 464 459 - 5 459 470 11 7 466 460 - 6 460 465 5 465 475 10 16.25% crude protein 8 467 461 - 6 461 465 4 465 486 21 Male 9 406 430 24 430 455 25 455 461 6 10 403 417 14 417 421 4 421 430 9 19.56% crude protein 11 414 395 -19 395 424 29 424 410 -14 12 413 411 - 2 411 411 0 411 428 17 o TABLE II Nutrient Intakes TREATMENTS Animal No. Week 1 Week 2 Week 3 Sex Ration Energy Intake (kcal) Dry Matter Intake (g) Organic Matter Intake (g) Protein Intake (g) Energy Intake (kcal) Dry Matter Intake (g) Organic Matter Intake (g) Protein Intake (g) Energy Intake (kcal) Dry Matter Intake (g) Organic Matter Intake (g) Protein Intake (g) Female 16.25% crude protein 1 2 3 332 584 775 75 132 175 68 120 159 12.2 21.5 28.4 475 710 879 107 160 198 97 145 179 17.4 26.0 32.0 581 484 519 131 109 117 119 99 106 21.3 17.7 19.0 19.56% crude protein 4 5 6 667 871 553 151 196 125 138 179 114 29.5 38.3 24.5 730 538 556 164 121 125 149 110 114 32.1 23.7 24.5 494 445 356 111 100 80 101 91 73 21.7 19.6 15.6 Male 16.25% crude protein 7 8 9 523 669 758 118 151 171 107 137 155 19.2 24.5 27.8 520 821 955 116 185 215 105 168 195 18.9 30.1 34.9 298 618 670 67 139 151 61 126 137 10.9 22.6 24.5 19.56% crude protein 10 11 12 827 508 636 187 115 144 170 105 131 36.6 22.5 28.2 707 725 734 159 163 165 145 148 150 31.1 31.9 32.3 450 570 538 101 128 121 92 117 110 19.8 25.0 23.7 4> Table III Apparent Digestible Energy Data TREATMENTS Animal No. Total ene consumed( cgy ccal) Total feces excreted (gm) Caloric density feces3(kcal/gm) Total fecal energy (kcal) Percent digestible energy Sex Ration Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Female 16.25% crude protein 1 2 3 332 584 775 475 710 879 581 484 519 27.4 47.7 55.3 37.4 46.9 51.9 54.2 44.3 38.9 4.32 4.23 4.14 4.33 4.26 4.36 4.26 4.16 4.08 118 202 229 185 227 259 231 184 159 64.5 65.5 70.5 62.1 68.0 70.5 60.3 62.0 69.6 19.56% crude protein 4 5 6 667 871 553 730 538 556 494 445 356 46.6 54.7 36.7 46.9 41.3 36.4 43.7 34.5 26.0 4.37 4.23 4.20 4.49 4.18 4.21 4.20 4.10 4.07 204 232 154 241 197 175 184 142 106 69.4 73.3 72.2 67.0 63.4 68.5 62.8 68.1 70.3 Male 16.25% crude protein 7 8 9 523 669 758 520 821 955 298 618 670 36.4 54.0 56.6 37.4 61.2 63.8 35.2 55.8 64.3 4.12 4.14 4.32 4.29 4.20 4.30 4.04 4.14 4.22 150 224 245 183 294 313 142 231 271 71.3 66.5 67.7 65.0 64.2 67.3 53.4 62.6 60.0 10 827 707 450 57.7 51.2 43.4 4.21 4.34 4.30 243 254 187 70.6 64.1 58.5 19.56% crude 11 508 725 570 40.4 52.5 45.6 4.13 4.19 4.15 167 251 189 67.1 65.4 66.9 protein 12 636 734 538 50.4 48.5 43.9 4.32 4.25 4.33 218 236 190 65.7 68.9 64.7 A l l yalues are means of duplicate determinations. Table IV Apparent Dry Matter Digestibility Data TREATMENTS Animal Feed Intake (g) D.M. Intake (g) D.M. Fecal Percent Dry Matter No. Output (g) Digestibi! Lity Sex Ration Week 1 Week 2 Week 3 Week 1 Week 2 Week 3 Week 1 Week 2 Week 3 Week 1 Week 2 Week 3 1 84 1 2 0 1 4 7 75 1 0 7 1 3 1 2 7 . 4 3 7 . 4 5 4 . 2 6 3 . 5 6 7 . 5 6 1 . 3 1 6 . 2 5 % crude 2 1 4 8 1 8 0 1 2 3 132 1 6 0 1 0 9 4 7 . 7 4 6 . 7 4 4 . 3 6 3 . 9 7 2 . 4 6 2 . 5 protein u' _m *_ 1 a 3 1 9 7 2 2 2 1 3 1 175 1 9 8 1 1 7 5 5 . 3 5 1 . 9 3 8 . 9 6 8 . 4 7 4 . 8 6 8 . 9 r cmcixc 4 1 7 0 184 1 2 5 1 5 1 1 6 4 1 1 1 4 6 . 6 4 6 . 9 4 3 . 7 6 9 . 1 7 2 . 9 6 3 . 6 1 9 . 5 6 % crude 5 2 2 1 1 3 6 112 1 9 6 1 2 1 1 0 0 5 4 . 7 4 1 . 3 3 4 . 5 7 2 . 2 6 8 . 2 6 8 . 4 protein 6 1 4 0 1 4 0 90 1 2 5 1 2 5 80 3 6 . 7 3 6 . 5 2 6 . 0 7 0 . 6 7 2 . 8 7 0 . 8 7 1 3 3 1 3 0 75 1 1 8 1 1 6 67 3 6 . 4 , 3 7 . 4 3 5 . 2 6 9 . 2 7 0 . 1 6 0 . 5 1 6 . 2 5 % crude 8 1 7 0 2 0 8 1 5 6 1 5 1 1 8 5 139 5 4 . 1 6 1 . 2 5 5 . 8 6 4 . 3 6 8 . 5 6 2 . 3 protein M a i a 9 1 9 3 2 4 2 1 7 0 1 7 1 2 1 5 1 5 1 5 6 . 6 6 3 . 8 6 4 . 3 6 7 . 1 7 1 . 5 6 0 . 0 naj-e 1 0 2 1 0 1 7 9 1 1 4 1 8 7 1 5 4 1 0 1 5 7 . 7 5 1 . 2 4 3 . 4 6 9 . 2 6 9 . 5 6 0 . 5 1 9 . 5 6 % crude 1 1 1 2 9 1 8 3 1 4 4 1 1 5 1 6 3 1 2 8 4 0 . 4 5 2 . 5 4 5 . 6 6 4 . 9 6 9 . 5 6 6 . 8 protein 12 162 1 8 5 1 3 6 1 4 4 1 6 5 1 2 1 5 0 . 4 4 8 . 5 4 3 . 9 6 5 . 0 7 2 . 1 6 6 . 3 Table V Apparent Organic Matter Digestibility Data TREATMENTS Animal O.M. intake Fecal D.M. Percent fecal Fecal O.M. Percent O.M. No. (g) (g) ash a (g) digestibility Sex Ration Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 1 68 47 1 1 9 2 7 . 4 3 7 . 4 5 4 . 2 1 5 . 5 1 7 . 9 1 6 . 2 2 3 . 2 3 0 . 7 4 5 . 4 6 5 . 9 6 8 . 4 6 1 . 9 1 6 . 2 5 % crude 2 1 2 0 1 4 5 99 4 7 . 7 4 6 . 7 4 4 . 3 1 7 . 0 1 7 . 9 1 7 . 8 3 9 . 6 3 8 . 3 3 6 . 4 6 7 . 0 7 3 . 6 6 3 . 3 protein L i 1 s*\ m A 1 y— 3 159 1 7 9 1 0 6 5 5 . 3 5 1 . 9 3 8 . 9 1 8 . 0 1 9 . 5 1 9 . 2 4 5 . 3 4 1 . 8 3 1 . 4 7 1 . 5 7 6 . 6 7 0 . 4 remaxe 4 1 3 8 1 4 9 1 0 1 4 6 . 6 4 6 . 9 4 3 . 7 1 8 . 0 1 7 . 6 1 7 . 7 3 8 . 2 3 8 . 6 3 6 . 0 7 2 . 3 7 4 . 1 6 4 . 4 1 9 . 5 6 % crude 5 1 7 9 1 1 0 91 5 4 . 7 4 1 . 3 3 4 . 5 1 9 . 0 1 8 . 9 1 8 . 8 4 4 . 3 3 3 . 5 2 8 . 0 7 5 . 3 6 9 . 6 6 9 . 2 protein 6 114 1 1 4 7 3 3 6 . 7 3 6 . 5 2 6 . 0 1 9 . 5 1 9 . 2 1 9 . 5 2 9 . 5 2 9 . 5 2 0 . 9 7 4 . 1 7 4 . 1 7 1 . 4 7 107 1 0 5 61 3 6 . 4 3 7 . 4 3 5 . 2 1 9 . 5 1 8 . 2 1 9 . 1 2 9 . 3 3 0 . 6 2 8 . 5 7 2 . 6 7 0 . 9 5 3 . 3 1 6 . 2 5 % crude 8 1 3 7 1 6 8 126 5 4 . 1 6 1 . 2 5 5 . 8 1 8 . 5 1 7 . 9 1 6 . 5 4 4 . 1 5 0 . 2 4 6 . 6 6 7 . 8 7 0 . 1 6 3 . 0 protein M ^ l _» 9 155 1 9 5 1 3 7 5 6 . 6 6 3 . 8 6 4 . 3 1 7 . 0 1 7 . 4 1 6 . 9 4 7 . 0 5 2 . 7 5 3 . 4 6 9 . 7 7 3 . 0 6 1 . 0 _iaxe 1 0 1 7 0 1 4 5 92 5 7 . 7 5 1 . 2 4 3 . 4 1 7 . 0 1 7 . 4 1 6 . 7 4 7 . 9 4 2 . 3 3 6 . 2 7 1 . 8 7 0 . 9 6 0 . 7 1 9 . 5 6 % crude 1 1 105 1 4 8 1 1 7 4 0 . 4 5 2 . 5 4 5 . 6 1 7 . 5 1 7 . 7 1 7 . 8 3 3 . 3 4 3 . 2 3 7 . 5 6 8 . 3 7 0 . 8 6 7 . 9 protein 1 2 131 1 5 0 1 1 0 5 0 . 4 4 8 . 5 4 3 . 9 1 7 . 0 1 7 . 8 1 6 . 6 4 1 . 8 3 9 . 9 3 6 . 6 6 8 . 1 7 3 . 4 6 6 . 7 A l l values are means of duplicate determinations. Table VI Apparent Digestible Protein Data TREATMENTS Animal Total protein Total D.M. Fecal Percent fecal Total fecal Percent digestible No. intake (g) output (g) protein protein (g) protein Sex Ration Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 1 12.2 17.4 21.3 27.4 37.4 54.2 17.6 15.7 20.7 4.8 5.9 11.2 60.7 66.1 48.5 16.25% crude 2 21.5 26.0 17.7 47.7 46.7 44.3 14.6 17.2 16.4 7.0 8.0 7.3 67.4 69.3 58.8 protein 3 28.4 32.2 19.0 55.3 51.9 38.9 17.6 13.9 15.5 9.7 7.2 6.0 65.9 77.6 68.4 Female 4 29.5 32.1 21.7 46.6 46.9 43.7 13.3 15.7 15.0 6.2 7.4 6.6 79.0 77.0 69.6 19.56% crude 5 38.3 23.7 19.6 54.7 41.3 34.5 18.8 17.6 17.0 10.3 7.3 5.9 73.1 69.2 69.9 protein 6 24.5 24.5 15.6 36.7 36.4 26.0 17.0 17.0 15.2 6.2 6.2 4.0 74.7 74.7 74.3 7 19.2 18.9 10.9 36.4 37.4 35.2 13.0 12.8 11.1 4.7 4.8 3.9 75.5 74.6 64.3 16.25% crude 8 24.5 30.1 22.6 54.0 61.2 55.8 17.6 19.1 19.4 9.5 11.7 10.8 61.3 61.1 52.2 protein Mo "1 9 27.8 34.9 24.5 56.6 63.8 64.3 18.0 18.7 20.3 10.2 11.9 13.0 63.3 66.0 47.0 riaxe 10 36.6 31.1 19.8 57.7 51.2 43.4 17.8 16.7 14.3 10.3 8.6 6.2 71.9 72.3 68.7 19.56% crude 11 22.5 31.9 25.0 40.4 52.5 45.6 13.0 14.3 18.0 5.2 7.5 6.8 76.9 76.5 72.8 protein 12 28.2 32.3 23.7 50.4 48.5 43.9 18.0 19.4 20.3 9.0 9.4 8.9 68.1 70.9 62.5 Al l values are means of duplicate determinations. Table VII Protein Utilization Indices TREATMENTS Animal N Intake (mg) Fecal N (mg) Urinary N (mg) Apparent Bio- Apparent Net Pro-No. logical Value % tein utilization % Sex Ration Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 Wk.l Wk.2 Wk.3 1 1,950 2,782 3,406 773 938 1,794 356 535 569 69.8 71.0 64.7 42.1 47.0 30.6 16.25% crude 2 3,432 4,160 2,834 1,116 1,284 1,161 658 938 534 71.3 67.4 68.1 48.3 46.6 40.2 protein 3 4,550 5,148 3,042 1,559 1,152 965 1,035 1,227 790 65.4 69.3 62.0 43.0 53.8 42.3 Female 4 4,723 5,133 3,474 993 1,177 1,049 1,078 1,088 732 71.1 72.5 69.8 56.2 55.9 48.7 19.56% crude 5 6,135 3,787 3,130 1,685 1,165 938 1,571 975 728 64.7 62.8 66.8 46.9 43.5 46.7 protein 6 3,913 3,913 2,504 998 993 632 936 899 747 67.9 69.2 60.1 50.6 51.6 44.9 7 3,068 3,016 1,742 757 767 627 825 762 391 64.3 66.1 65.0 48.4 49.3 41.6 16.25% crude 8 3,926 4,810 3,614 1,526 1,873 1,769 896 1,075 756 62.7 63.4 59.0 38.3 38.7 30.1 protein Mo 1 *a 9 4,446 5,590 3,926 1,630 1,908 2,089 811 1,256 625 71.2 65.9 66.0 45.1 43.4 30.9 riaxe 10 5,853 4,976 3,161 1,644 1,367 994 1,317 1,075 737 68.7 70.2 66.0 49.7 50.9 45.2 19.56% crude 11 3,600 5,101 4,006 840 1,202 1,094 1,041 1,525 1,025 62.3 60.9 64.8 47.8 46.5 47.1 protein 12 4,507 5,164 3,787 1,451 1,537 1,427 914 1,005 767 70.1 72.3 67.5 47.5 50.8 42.1 

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