[目的]探讨维生素AD和亚硒酸钠维生素E对母牛胎衣不下的预防作用。[方法]选取健康西门塔尔乳肉兼用母牛240 头,随机分为试验组A（A1组、A2 组、A3 组）和对照组（B组）。试验组分别在产前40 天、15 天及产后20 min,深部肌内注射维生素AD注射液10 mL（A1组）、亚硒酸钠维生素E注射液10 mL（A2组）、维生素AD与亚硒酸钠维生素E注射液各10 mL（A3组）,对照组不注射（B组）。统计牛胎衣不下的比例和高发季节。[结果]母牛联合注射维生素AD与亚硒酸钠维生素E注射液,对预防母牛产后胎衣不下效果极显著（P<0.01）。夏季高发于其他季节。[结论]母牛产前及产后联合注射维生素AD、亚硒酸钠维生素E,可有效预防胎衣不下。

[Objective] To investigate the preventive effect of Vitamin AD and sodium selenite and Vitamin E on the retention of afterbirth in dairy Cows. [Method] Two hundred and forty healthy simmental dairy cows were selected and randomly divided into experimental group A1,A2,A3,and control group B. The experimental groups were treated at 40,15 days before birth,and 20 minutes after delivery,respectively,deep intramuscular injection of Vitamin AD injection 10 mL（group A1）,sodium selenite and Vitamin E injection 10 mL（group A2）,Vitamin AD and soudiun selenite and Vitamin E injection 10 mL each（group A3）,control group did not receive injection（group B）.The proportion and season of cows with the retention of afterbirth were counted. [Result] The effect of Vitamin AD combined with sodium selenite and Vitamin E injection on the prevention of the retention of afterbirth in cows is very significant（P<0.01）,with higher incidence in summer than in other seasons. [Conclusion] Prenatal and postpartum combined injection of Vitamin AD,sodium selenite and Vitamin E can effectively prevent the retention of afterbirth in dairy cows.