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. r...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.Minimumm digestible energy intase of 153.5kcal/kg0.75/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 conccntration. Rumen NH3-N production changes with season, but seasonal changcs 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 strcss. Endogenous urinary nitrogen is 0.09 (red deer) and 0. 16 g N/kg0.75day (elk), and metabolic frcal 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 limite.Much work is urgently needed in metabolism and requirements of protein before the appropriate feeding standard of red deer is coming.展开更多
文摘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.Minimumm digestible energy intase of 153.5kcal/kg0.75/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 conccntration. Rumen NH3-N production changes with season, but seasonal changcs 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 strcss. Endogenous urinary nitrogen is 0.09 (red deer) and 0. 16 g N/kg0.75day (elk), and metabolic frcal 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 limite.Much work is urgently needed in metabolism and requirements of protein before the appropriate feeding standard of red deer is coming.
