不同激素处理方式在肉牛同期发情中的应用效果研究OA

To screen a suitable estrus synchronization protocol for large-scale beef cattle farming in the Jiu-quan region of Gansu and improve the reproductive efficiency of cows,this study compared the application effects of different estrus synchronization procedures.A total of 66 2-3 years old non-pregnant high-gene-ration crossbred Simmental cows were selected as experimental subjects.Four drugs,namely controlled in-ternal drug release(CIDR),pregnant mare serum gonadotropin(PMSG),gonadotropin-releasing hormone(GnRH)and cloprostenol sodium(PGF2α),were used to implement three estrus synchronization protocols:Protocol Ⅰ(CIDR+PGF2α+PMSG),Protocol Ⅱ(GnRH+PGF2α+GnRH),and Protocol Ⅲ (PGF2α+PGF2α).The estrus synchronization rate,conception rate during the estrous cycle,overall concep-tion rate of treated cows and drug cost of each protocol were compared.The results showed that the estrus synchronization rates of Protocol Ⅰ and Protocol Ⅱ were 86.36％and 81.82％,respectively,both signifi-cantly higher than that of Protocol Ⅲ(P ≤ 0.05),while no significant difference was observed between Protocol Ⅰ and Protocol Ⅱ(P＞0.05).The overall conception rates of treated cows in Protocol Ⅰ and Pro-tocol Ⅱ were 63.64％and 59.09％,respectively,with no significant difference between the two groups(P＞0.05),but both were significantly higher than that of the Protocol Ⅲ group(P ≤0.05).Considering the comprehensive factors including economic cost and operational simplicity,the GnRH+PGF2α+GnRH protocol has the advantages of easy operation and low cost while ensuring high reproductive performance,making it more suitable for promotion and application in large-scale beef cattle farms in the Jiuquan region.