Maintenance Protein Requirement And Utilization Of Protein And Energy By Weaned Sika Deer

In Experiment I, three weaned sika deer with similar age and at healthy condition housed in individual metabolic cages were successively fed 5 diets with crude protein levels being 10 %(diet A) ,12 %(diet B), 14 %(diet C) ,16 %(diet D) and 18 %(diet E), respectively. Each diet were given to the animals for 10 days of preliminary feeding followed by 5 days samples collecting period. Dietary nutrient digestion and nitrogen metabolism in the experimental animal were determined, and maintenance protein requirement for weaning sika deer was suggested.In experiment II, 4 iso-nitrogenous diets with maintenance level of protein, based on the suggested protein requirement of Experiment I, but different levels of metabolizable energy achieved by inclusion of different levels of corn (0 % (diet 1), 5 %(diet 2), 10 %(diet 3) and 15 %(diet 4)) were formulated and fed to the above animals. The percentages of concentrate in the diets were 28.6,32.2,35.7 and39.3 respectively. Feed intakes, dietary nutrient digestion and uric acid equivalent excretion in the urine by the animals were examined.The results of Experiment I showed that as the dietary protein level increased, N intake ,urinary N excretion were significantly increased (p<0.05), N apparent digestibility were significantly increased (p<0.01), with protein level of 16.5 % being the highest and 9.95 % the lowest. N retention for diets diet A, diet B, diet C, diet D and diet E were -0.94,0.01,1.01,2.27 and 1.88 g/d respectively. Linear regression analysis indicated that N retentions (Y) were linearly related to CP content (X) of diets in the range of protein levels investigated in the experiment. Following equation was derived:Y = - 4.808 + 0.3915X (r=0.96, R~2=0.92, p<0.05)The equation suggests that as dietary protein is zero, N balance is -4.808g. If N excretion is considered as maintenance requirement of weaned sika deer when they are fed protein free diet, the maintenance requirement of deer at this stage will be 4.808 g N or (4.808x6.25) g crude protein. If N balance is zero (maintenance), the corresponding dietary CP level would be 12.27 % (when Y=0, X=12.27 %). It is argued that the protein requirement of weaned sika deer is 4.808g N/d or the protein content of diet is 12.27 %.Protein levels of diets did not significantly affect intakes of dietary DM, OM, NDF and GE and digestibilities of these nutrients.The results of Experiment II, as energy levels (the inclusion of corn) increased, dry matter intake, organic matter intake, N retention, CP intake, crude fiber intake and gross energy intake were not significantly...