奶牛产后胎衣不下对奶牛业造成极大的经济损失。

The retained fetal membranes has caused great ecological damage to the breeding of dairy cows.

它严重影响奶牛的繁殖力，给奶牛业造成严重的经济损失。

It seriously affected the productivity of cow, and cause enormous economic losses to the cow rearing industry.

奶牛业是奶业系统的一个重要组成部分，主要包括奶牛培育、奶牛饲养、疫病防治和原奶生产四个环节。

Milch cow industry is one of important part of dairy industry, including breeding milch cow, raising milch cow, preventing and cure of the epidemic disease and milk production.

奶牛的胎衣不下，是严重影响奶牛经济效益的常见病。

Retention of the afterbirth of the cow is the common disease to seriously affect the economy mileage.

奶牛情期受胎率是影响奶牛繁育率的重要因素之一。

The rate of cow's oestrum fecundation is one key factor of cattle's breeding rate.