不同蛋白质水平代乳粉对牦犊牛体重及血清生化指标的影响

为探究西藏地区牦牛代乳粉哺育犊牛的适宜蛋白质水平,本试验以藏区高山牦牛为研究对象,研究不同蛋白水平对哺乳期牦犊牛的体重和血清学指标的影响,以筛选出蛋白质水平最佳的代乳粉。选取40头新生当雄县牦犊牛,随机分为4组(n=10):对照组犊牛随母牦牛哺乳(CON),试验组犊牛分别饲喂蛋白水平为21.95%低蛋白组(LP)、24.28%中蛋白组(MP)和26.11%高蛋白组(HP)3种牦牛代乳品。饲喂时间为犊牛30～90d日龄,期间跟踪测定犊牛体重,并分别在30、60和90d日龄采集血清进行分析。结果表明:饲喂3种代乳粉的犊牛体重均显著高于对照组(P0.001),120d日龄时HP组犊牛体重达到最高值;3种代乳粉对犊牛血清抗氧化指标和免疫指标产生一定的影响,其中HP组谷胱甘肽过氧化物酶活性有高于LP组的趋势(0.05P0.1),且HP组丙二醛含量及肿瘤坏死因子a较其他3组低,而免疫球蛋白(IgG、IgM)及谷胱甘肽过氧化物酶、丙氨酸氨基转移酶、天冬氨酸氨基转移酶活性均较其他3组高。综合分析显示在西藏地区蛋白水平为26%的牦牛代乳粉饲喂哺乳期牦犊牛的效果较好。

Effects of different protein levels of milk replacer on the body weight and serum biochemical indexes of yak calves

In order to explore the appropriate protein level of milk replacer for yak calves, three milk replacers of different protein levels were used in this study to investigate their effects on the body weight and serum parameters of mountain yak calves during lactation period. Forty newborn male yaks in Dangxiong County were selected and randomly divided into four treatment groups(n=10). The calves in the control group were fed naturally by their mothers, and the calves in the test groups were fed with three yak milk replacers with protein content of 21. 95%(LP), 24. 28%(MP)and 26. 11%(HP), respectively. From age of 30 to 90 d, the body weight of yak calves was measured and their serum samples were collected at 30, 60 and 90 d of age. The results showed that the body weight of yak calves in the experimental groups were significantly higher than in the control group(P<0. 001). At 120 d of age, the body weight of yak in MP group was the highest, and there was a significant difference between the control group and HP group(P<0. 05). The GSH-Px activity in HP group was significantly higher than that of LP group. The contents of MDA and TNF-a in HP group were relatively low. And the IgG, IgM, ALT and AST levels were relatively high. In conclusion, the growth performance and serum index of yak were the best in the HP group with protein level of milk replacer 26%.