黑龙江动物繁殖2025，Vol.33Issue(4)：29-34,6.DOI:10.19848/j.cnki.ISSN1005-2739.2025.08.0005
来曲唑处理对绵羊同步排卵程序同期发情效果的影响
Effects of letrozole treatment on estrus synchronization in sheep using synchronization of ovulation protocol
摘要
Abstract
This experiment aims to explore the effects of letrozole(LE)combined with the synchronization of ovulation(Ovsynch)program on estrus synchronization in ewes.In experiment 1,30 multiparous Mongolian ewes in breeding season were randomly divided into three groups,each containing 10.The Ovsynch group received sequential injections of solvent,gonadotropin-releasing hormone(GnRH)and prostaglandin F2α(PGF2α)according to a standardized protocol,and the low and high LE treatment groups were administered with doses of LE(0.125 mg/kg and 0.25 mg/kg),respectively,for two consecutive days prior to undergoing the same Ovsynch treatment regimen.Twelve hours after the last injection of GnRH,ewes in all groups were teased with rams.Ewes in estrus would receive artificial insemination(AI)once at 12 hours and once at 24 hours in heat,respectively.In experiment 2,20 multiparous Mongolian sheep were randomly divided into the Ovsynch group and the high LE treatment group.The hormone treatment protocol was the same as that of the high LE treatment group in experiment 1.All ewes underwent fixed-time artificial insemination(FTAI)at 16 and 24 hours after the second injection of GnRH,respectively.The results showed that pretreatment with a high dose of LE(0.25 mg/kg)for two days before the first GnRH injection significantly reduced serum estradiol(E2)concentrations(P<0.05),increased the diameter of the largest ovarian follicle at the time of the first GnRH injection(P<0.05),enhanced the ovulation rate induced by the first GnRH injection,and led to more synchronized estrus onset among ewes receiving the same protocol.Moreover,LE pretreatment also increased the pregnancy and lambing rates of ewes in the Ovsynch program(P>0.05).In conclusion,LE treatment could make differences in estrus synchronization of ewes in increasing the ovulation rate after the first GnRH injection and improving estrus synchrony following the second GnRH injection in the Ovsynch protocol,thereby contributing to improved reproductive performance in ewes to some extent.关键词
繁殖季节/同期发情/来曲唑/绵羊/繁殖性能Key words
breeding season/estrus synchronization/letrozole/sheep/reproductive performance分类
农业科技引用本文复制引用
段增祎,刘树才,石景君,侯健,齐琪,刘孟豪,李俊进,余芷璇,刘永合,单德海,李巍巍,徐惠娟..来曲唑处理对绵羊同步排卵程序同期发情效果的影响[J].黑龙江动物繁殖,2025,33(4):29-34,6.基金项目
国家绒毛用羊产业技术体系建设项目(CARS-39-04) （CARS-39-04）
国家重点研发计划项目(2017YFD0501902) （2017YFD0501902）
