营养调控结合同期发情技术提升甘南牦牛繁殖效率的效果分析OA

To address the prominent problems of obvious seasonal estrus,prolonged postpartum anestrus,and low reproductive efficiency of Gannan yaks under the natural grazing mode,and promote the transfor-mation of the yak industry from traditional extensive breeding to intensive and efficient breeding,this study systematically analyzed the synergistic effect of nutritional regulation combined with estrus synchronization technology on improving the reproductive efficiency of Gannan yaks.A total of 90 lactating female yaks with good health,similar body condition scores,and 3 to 6 months postpartum were randomly divided into three equal groups.Group Ⅰ adopted the natural grazing plus natural mating mode.Group Ⅱ adopted the estrus synchronization plus artificial insemination mode.Group Ⅲ adopted the combined mode of nutritional regulation+estrus synchronization+artificial insemination.Indicators including estrus rate,conception rate,reproduction rate,and calf growth performance of female yaks in the three groups were determined and compared.The results showed that the estrus rate,conception rate and reproduction rate of female yaks in Group Ⅲ were 83.3％,80.0％and 73.3％respectively,which were significantly higher than 73.3％,77.3％and 43.3％in Group Ⅱ(P≤0.05).Group Ⅰ had a natural estrus rate of only 13.3％,a conception rate of 50.0％and a reproduction rate of 6.7％,which were extremely significantly lower than those of the other two experimental groups(P≤0.01).The birth weight and weaning weight of calves in Group Ⅲ were 15.6 kg and 63.5 kg respectively,significantly higher than 14.8 kg and 61.6 kg in Group Ⅱ(P≤0.05),and extremely significantly higher than 12.6 kg and 50.7 kg in Group Ⅰ(P≤0.01).The calf survival rate of Group Ⅲ reached 90.9％,which was significantly higher than 69.2％in Group Ⅱ and 50.0％in Group Ⅰ (P≤0.05).The above findings indicate that the integrated mode of nutritional regulation combined with es-trus synchronization and artificial insemination can significantly improve the reproductive efficiency of fe-male yaks and the growth performance of calves,which is worthy of popularization and application in large-scale yak breeding in Gannan.