Nitrogen metabolism in elk cervus elaphus nelsoni
Mould, E.D.; Robbins, C.T.
Journal of Wildlife Management 45(2): 323-334
ISSN/ISBN: 0022-541X Accession: 005986852
N metabolism of elk (C. e. nelsoni) was investigated during 15 feeding trials of single- and multiple-component rations. Endogenous urinary N was 0.16 g N/kg0.75 per day, metabolic fecal N was 5.58 g N/kg dry-matter intake, apparent N digestibility ranged from -99.9-88.0% and true N digestibility was 98.0%. Feed N concentration was significantly related to fecal N content for phenolic-free rations. Ingested phenolies significantly increased fecal N excretion. Urea kinetic experiments were conducted in conjunction with 8 of the in vivo trials in which elk recycled 18-85% of the urea produced, which represented 23.9-198.0% of their dietary N intake. Biological value of dietary protein fell from 100-42% as dietary protein content increased from 5.6 to 29.3%. Digestible energy intake necessary to maintain a positive N balance was 153 kcal/kb0.75 per day. Estimates of dry matter intake needed to meet maintenance N requirements at varying dietary crude-protein concentrations are presented.