定时输精对奶牛第一情期受胎率的效果分析

[目的]探讨不同月份和精液类型对利用定时输精程序处理奶牛后第一情期受胎率的影响.[方法]选择93头产后60 d以上不发情和产后配1～3次仍未受胎的奶牛,不检查卵巢直接利用激素生源2+1进行同期发情处理.1～3月份处理41头奶牛,6～8月份处理52头;其中,利用性控精液配种58头,常规精液配种35头.[结果]表明:经定时...

Influence on the Conception Rate of the First Estrus in Dairy Cows by Timed Artificial Insemination Protocol

【Objective】To investigate the potential influences of month and semen type on the pregnancy rate of the first estrus in dairy cows implemented with timed artificial insemination(TAI) protocol.【Method】 A total of 93 dairy cows were selected in this study.Dairy cows were those didn’t have estrus 60 days postpartum(or even longer) and those failed in pregnancy after inseminating 1~3 times.Synchronization of estrus was performed using the "Shengyuan2+1" method without checking the follicular development.Data of 41 dairy cows administered with the method from January to March and 52 dairy cows from June to August were collected.Separately,58 dairy cows were inseminated with sexed semen while 35 dairy cows with conventional semen.【Result】THe results showed that the pregnancy rate of the first estrus was 41.9% in dairy cows implemented with TAI protocol,which was 11.4% higher than that in cows with natural estrous.The pregnancy rate from January to March and June to August increased 13.4% and 9.9%,respectively.In addition,the conception rate using the conventional semen and the sexed semen increased 20.9% and 5.7%,respectively.【Conclusion】We concluded that TAI was a good method for dairy cows management.Month and semen types had different but significant effect on the conception rate in dairy cows with the TAI protocol.Higher conception rate could be seen from January to March or cows using the conventional semen.