【摘要】 随着奶牛养殖业的持续发展,现代化奶牛场对提高繁殖力有了更高的需求。为了改良同期发情-定时输精(Ovsynch-TAI)技术,试验将250头产后50天左右荷斯坦奶牛分为5组,对照组为正常Ovsynch-TAI组; A组、B组在原Ovsynch-TAI程序之前和之后分别肌肉注射亚硒酸钠-维生素E,C组在定时输精后5天肌肉注射人绒毛膜促性腺激素(h CG),D组在定时输精后5天肌肉注射促性腺激素释放激素(GnRH),测定各组受胎率。结果表明:对照组受胎率为34%,A、B、C、D组受胎率分别为36%、28%、52%、50%,其中C、D组极显著高于对照组(P <0.01),A、B组与对照组差异不显著(P> 0.05)。说明在实施同期发情处理前后肌肉注射亚硒酸钠-维生素E对同期发情处理奶牛的受胎率没有影响,定时输精后5天肌肉注射hCG和GnRH均能显著提高奶牛受胎率。更多还原

【Abstract】 With the continuous development of dairy farming,modern dairy farms have a higher demand for improving fecundity. In order to improve the estrus-timed insemination( Ovsynch-TAI) technique,the experiment divided 250 Holstein cows about 50 days postpartum into 5 groups. The control group was the normal Ovsynch-TAI group. Group A and Group B were injected intramuscularly with sodium selenite and vitamin E before and after the original Ovsynch-TAI procedure. Group C received intramuscular injection of human chorionic gonadotropin( h CG) 5 days after timed insemination. In group D,gonadotropin releasing hormone( GnRH) was injected intramuscularly 5 days after timed insemination,and the conception rate of each group was determined. The results showed that the conception rate of the control group was 34%,and the conception rates of groups A,B,C,and D were 36%,28%,52%,and 50%,respectively. Among them,groups C and D were significantly higher than the control group( P < 0. 01),the difference between group A and group B and the control group was not significant( P > 0. 05). It shows that intramuscular injection of sodium selenite-vitamin E before and after the simultaneous estrus treatment has no effect on the conception rate of the cows in the same period,and the injection of h CG and GnRH into the muscle 5 days after insemination could significantly improve the conception rate of dairy cows.更多还原