Protein nutrition in red deer (Cervus elaphus)

Abstract

Red deer can adjust to seasonal change of forage quality to maintain a relatively constant crude protein level (21.1±4.0, 14.7±1.0, 11.1±1.1 and 6.5±0.8 in spring, summer, fall and winter, respectively). Apparent protein digestibility is variable from −99.9% to 97.5% depending upon season and forage type. True protein digestibility is 99%. Digestion of protein is significantly influenced by phenolics in diets. Minimum digestible energy intake of 153.5 kcal/kg^0.75/day is necessary to maintain a positive nitrogen balance. Red deer recycles 18–85% of the urea produced and urea kinetic parameters (urea pool size urea entry rate and urea excretion rate) are correlated to plasma urea concentration. Rumen NH₃-N production changes with season, but seasonal changes in other NH₃-N kinetic parameters (NH₃-N concentration, NH₃-N pool size and NH₃-N outflow rate) are in dispute. Protein metabolism may be promoted in response to cold stress. Endogenous urinary nitrogen is 0.09 (red deer) and 0.16 g N/kg^0.75·day (elk). and metabolic fecal nitrogen is 5.58 g N/kg dry-matter intake. Protein requirements ranges from 100 g/kg DM to 170 g/kg DM for red deer of various ages and physiological stages. In conclusion, the knowledge of protein nutrition of red deer is limited. Much work is urgently needed in metabolism and requirements of protein before the appropriate feeding standard of red deer is coming.

Keywords

red deer / cervus elaphus / protein / nutrition