日粮能量水平对奶牛繁殖性能、血浆代谢产物和生殖激素的影响

为了解日粮能量水平对泌乳奶牛生殖机能的影响,选取年龄、体重、胎次、泌乳量相近的健康泌乳奶牛40头,按添加过瘤胃脂肪量分为高（H,400g/d/头）、中（M,300g/d/头）、低（L,200g/d/头）和对照组（不添加过瘤胃脂肪）四组,每组10头,试验期为产后30d至70d。产后30d、45d、60d、70d以及发情时记录试验奶牛采食量、体况分,记录繁殖性能,检测奶牛血浆GLU、BUN、ALB、TP、LH、FSH、E2、P4和PG浓度,结果显示：1）试验奶牛繁殖性能高低依次为H组、M组、L组和对照组。2）血浆GLU水平H组〉M组〉L组〉对照组;BUN水平L组〉M组〉H组;ALB和TP各组间无差异。3）血浆LH、FSH、E2水平随能量摄入增加而升高。这些结果提示：高能量摄入能缓解奶牛能量负平衡,促进卵泡正常性周期活动,从而提高奶牛繁殖性能。

The Effect of Dietary Energy Levels on Reproductive Performances, Plasma Metabolites and Reproductive Hormones of Lactating Cows

To understand the effect of dietary energy levels on cow reproductive function during lactation,forty healthy dairy cows with similar ages,body weight,parities and milk yield were selected and divided into four groups according to the adding amount of the rumen bypass protected fat,which were group H（400g/d per cow）,group M（300g/d per cow）,group L（200g/d per cow） and control group（no addition）,ten cows per group.The tested period was from 30 days to 70 days after calving.For all experimented cows,the biochemical indexes（glucose,urea nitrogen,albumin,total protein,LH,FSH,E2,P4 and PG） were detected at days 30,40,50,60,70.The results showed that.1） the level of the blood glucose from high to low was in turn group H,group M,group L,and control group,the level of plasma urea nitrogen from high to low was in turn group L,group M,group H,and control group,and there was no difference in the level of plasma albumin and total protein among three groups.2） with the increase of energy intake,the level of plasma LH,FSH,and E2 rised.These results suggested that high dietary energy levels could alleviate negative energy balance of cows,and promote follicles cycle activity,eventually improve reproductive performance.