饲喂水平对泌乳期牦牛生产性能、瘤胃发酵和血清生化指标的影响

Effect of feeding level on production performance,rumen fermentation and serum biochemical indicators of yak during lactation

试验探究不同饲喂水平对泌乳期牦牛生产性能、瘤胃发酵和血清生化指标的影响。选择15头体重、产犊日期接近的健康经产母牦牛,随机分为3组,即自由采食组(AL组)、80%采食组(IR80组)和60%采食组(IR60组),每组5个重复。结果显示,IR60组的牦牛平均日增重、泌乳后期乳产量、泌乳前期乳蛋白含量显著低于AL组(P<0.05)。泌乳期牦牛瘤胃液氨态氮含量随饲喂水平的降低而升高(P<0.05),瘤胃总挥发性脂肪酸含量随饲喂水平的降低而降低(P<0.05)。牦牛泌乳后期血清尿素氮含量显著高于泌乳前期(P<0.05),AL组牦牛泌乳前期血清谷丙转氨酶活性显著高于其他组(P<0.05)。AL组与IR80组牦牛泌乳后期血清中黄体酮含量高于泌乳前期(P<0.05),IR60组牦牛泌乳前期的催乳素含量和泌乳后期的雌二醇含量显著高于其他组(P<0.05)。研究表明,泌乳期牦牛需供给高营养水平的日粮以保证牦牛良好的瘤胃代谢、激素代谢水平及较高的生产性能。

The experiment explored the effect of different feeding levels on lactation yak production performance,rumen fermentation and serum biochemical indicators.15 healthy female yaks with close calving dates were randomly divided into three groups,namely free feeding group(AL group),80%feeding group(IR80 group)and 60%feeding group(IR60 group),with five replicates in each group.The results showed that the average daily gain,milk production in late lactation and milk protein content during pre-lactation period of yak in IR60 group were significantly lower than those in AL group(P<0.05).The content of ammonia nitrogen in rumen fluid of yak during lactation increased with the decrease of feeding level(P<0.05),and the content of total volatile fatty acid in rumen decreased with the decrease of feeding level(P<0.05).The serum urea nitrogen content of yak in late lactation period was significantly higher than that in pre-lactation period(P<0.05),and the serum alanine aminotransferase activity of yak in AL group was significantly higher than that of other group(P<0.05).The serum progesterone content of yaks in AL group and IR80 group during late lactation was higher than that of pre-lactation period(P<0.05),and the prolactin content of the yak in the IR60 group during prelactation period and the estradiol content in late lactation were significantly higher than other groups(P<0.05).The experiment indicates that the yak during lactation needs to be supplied with high nutritional level diets to ensure good rumen metabolism,hormone metabolism level and high production performance of the yak.