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Bibliography Note: |
Includes bibliographical references (leaves 25-30, 49-51,70-72). |
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Dissertation Note: |
Ph. D. Washington State University |
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General Note: |
"Doctor of Philosophy, Washington State University, Department of Zoology, 1980." |
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Dissertation Note: |
Ph. D. Washington State University 1980 |
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Summary, Etc. Note: |
Abstract: Part 1. Nitrogen metabolism of elk was investigated during 15 feeding trials of single and multiple component rations. Endogenous urinary nitrogen was 0.16 g N/kg('0.75)/day, metabolic fecal nitrogen was 5.58 g N/kg dry matter intake, apparent nitrogen digestibility ranged from -99.9 to 88.0%, and true nitrogen digestibility was 98.0%. Feed nitrogen concentration was significantly related to fecal nitrogen content for phenolic-free rations. Ingested phenolics significantly increased fecal nitrogen excretion. Urea kinetic experiments were conducted in conjunction with 8 of the in vivo trials in which elk recycled from 18 to 85% of the urea produced which represented from 23.9 to 198.0% of their dietary nitrogen intake. Biological value of dietary protein fell from 100 to 42% as dietary protein content increased from 5.6 to 29.3%. Digestible energy intake necessary to maintain a positive nitrogen balance was 153 kcal/kg('0.75)/day. Estimates of dry matter intake to meet maintenance nitrogen requirements at varying dietary crude protein concentrations are presented. |
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Abstract: Part 2. The efficiency of carbohydrate and protein extraction from browses by detergent solutions was investigated. Standard and sequential acid detergent extractions removed virtually all of the hemicellulose, total soluble sugars, water soluble polysaccharides, and pectin. Sequential extraction of browses with neutral and acid detergents removed more of the protein than either neutral detergent or separate acid detergent while quantitatively retaining the cellulose. Neutral detergent removed an average of 22.4% of the hemicellulose and may have solubilized portions of the true lignin and cutin. Phenolic extraction and determination is recommended as a pretreatment to the analyses of browses. Because of possibly serious problems in using detergent analyses on browses, a possible modification of the procedure is proposed and the need for further studies is recognized. |
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Abstract: Part 3. Digestion by elk was investigated during 15 feeding trials of single and multiple component rations. Metabolic fecal losses increased in proportion to the fiber content of the feeds and were not significantly different from deer. Phenolics depressed cell soluble digestibility but not cell wall digestibility in single component rations but had no apparent effect upon cell wall or cell soluble digestibilities in mixed rations. Digestion of cell walls was depressed 3.2 units per unit of organic silica and was curvilinearly related to the lignin-cutin content of the acid detergent fiber. Elk digested more of the cell walls than deer. In vivo digestibilities were overestimated by in vitro trials when using poorly digested forages and were underestimated at the other extreme. Fiber digestion results further support a suggested change in detergent analyses. |