The Effect of Placenta Retention on Lactation Performances of Holstein Cows
To study the effect of placenta retention on lactation performance of dairy cows in different year,season,calving season,lactation stage and parity,and in order to provide a reliable theoretical basis for improving the lactation performance and milk quality of dairy cows.A total of 4247 dairy cows’ DHI production performance recorded were collected from 2013 to 2015,the lactation performances of dairy cows were measured by multiple factor variance (ANOVA) in different year,season,calving season,parity and lactation stage.The results showed that:the 4 traits of milk production,including somatic cell score,lactose and milk urea nitrogen were significantly affected (P＜0.05) by dairy cows with placenta retention in different calving season,season,year,lactation stage and parity.Placenta retention cows with spring,summer and autumn calves,had a lower significant effect on daily milk production than the normal cows (P＜0.05).Placenta retention cows with early lactation calves,had a lower significant effect on daily milk production than the normal cows (P＜0.05).Placenta retention cows tested in autumn and winter,had a lower significant effect on daily milk production than the normal cows (P＜0.05).Placenta retention cows with first and third parity calves,had a lower significant effect on daily milk production than the normal cows (P＜0.05).
国家科技期刊平台
NSTL
万方数据
维普
