胎衣不下对奶牛产后繁殖力的影响研究

通过对574头初产母牛和1269头经产母牛泌乳期资料的生物统计学分析,研究胎衣不下对产后奶牛繁殖力的影响,同时按母牛是否伴发子宫炎或(和)卵巢囊肿分组,比较了它们可能对产后繁殖力的影响。患子宫炎或(和)卵巢囊肿的母牛,其胎衣滞留时间的长短对产后繁殖力无明显影响。单纯胎衣滞留的初产母牛,首次配种受胎率明显降低。经产母牛中,胎衣滞留超过5天者,首次配种受胎率降低25％(P<0.05),空怀时间延长17天(P<0.05);若胎衣滞留时间超过7天,首次配种时间延迟21天(P<0.05),首次配种受胎率降低35％(P<0.01),空怀时间延长66天(P<0.01)。

The Effect of Retention of Placenta on Reproductivity in Postpartum Dairy Cows

The milking period data of 574 primiparous and 1269 pluriparous dairy cows were analysed by biometrics method. The results showed that the dairy cows that complication with metritis (include endometritis, puerperal endometritis and pyometra) and (or) ovarian cyst, there was no effect of the time of retention of placenta on reproductivity in postpartum period. The primiparous dairy cows that only have retention of placenta, its concept rate of postpartum first breeding decreased significently. In the pluriparous dairy cows, if the time of retention of placenta>5 days, the concept rate of postpartum first breeding decreased 25% (P<0. 05), the open days postponed 17 days (P<0. 05); if the time of retention of placenta>7 days, the time of postpartum first breeding postponed 21 days, the concept rate of postpartum first breeding decreased 35% (P<0. 01), the open days postponed 66 days.