哺乳牦牛隔离断乳及诱导发情技术试验研究

Study on Isolation Weaning in Lactating Yak and Induction Estrus

本研究旨在对哺乳牦牛在隔离断乳的基础上,考察断乳处理后母牦牛发情率及受胎率,并对未出现发情症状的试验牦牛,采用激素诱导发情处理,从而考察诱导发情处理后母牦牛诱导发情率及受胎率。隔离断乳结果表明,隔离断奶Ⅰ组、隔离断奶Ⅱ组及隔离断奶Ⅲ组试验牦牛的发情率和妊娠率对比差异不显著(P>0.05):激素诱导发情处理结果表明,PGF2α组与GnRH组的发情率及妊娠率对比差异显著(P<0.05);隔离断奶+PGF2α组与隔高断奶+GnRH组的总发情率及总妊娠率对比差异极显著(P<0.01),隔离断乳处理后,试验牦牛的发情高峰期主要集中在隔离断乳后的第12～13d。研究表明,在传统的放牧条件下,犊牛哺乳是影响牦牛进入发情季节正常发情排卵的关键影响因素,导致促黄休素分泌不足及卵泡发育受阻,通过犊牛的隔离断乳,进而采用诱导发情/人工授精技术,能够显著提高母牦牛的发情率和妊娠率。

This experiment was conducted to investigate rate of estrus and conception in weaning female yaks. Hormone - induced estrus was used for yaks which didn＇t appear estrus symptoms. The results showed that there was not a great difference among group Ⅰ, group Ⅱ and group Ⅲ of isolation weaning in rate of estrus and conception （ P 〉 0.05 ）. There was a significant difference between PGF 2α and GnRH of hormone - induced estrus treatment in rate of estrus and conception （ P 〈 0.05 ）. There is a very significant diffevence between isolation weaning ＋ PGF 2α group and isolation weaning ＋ GnRH group treament in total rate of estrus and conception （ P 〈 0.01 ）. The estrus peak period occur after 12,13d of weaning treatment. The research showed that calves lactation is key factor to affect ovulation in estrus seasonin tradional grazing condition, and lead to inadequat luteinizing - hormone secretes and affect follicular development. The isolation weaning,induction estrus and artificial insemination can improve rate of estrus and conception in female yaks greatly.