胎次对湖羊同期发情效果的影响

Effects of parity on synchronous estrus in Hu sheep

目的:比较不同胎次对母羊同期发情及繁殖性能的影响。方法:选择断奶2 d的健康湖羊母羊,其中第2胎次14只,第6~7胎次12只,同期发情参照Ovsynch方案,其LHRH-A3剂量为12.5μg/只,PG-CL剂量为0.1 mg/只,不再进行第2针GnRH处理,在PG-CL处理同时以PMSG肌肉注射,公羊试情直至发情结束,测定母羊发情率、发情持续时间等指标。在发情后20 h和间隔12 h 2次输入子宫颈内鲜精,测定发情母羊分娩率、窝产羔数、初生羔羊重等指标。结果:不同胎次母羊发情率均为100%,发情持续时间、PG-发情间隔、Gn-发情结束、窝产羔数和妊娠期等指标均无显著性差异(P>0.05),第6~7胎次母羊发情指标数据离均差均大于第2胎次。第2胎次初生羔羊体重高于第6~7胎次(P<0.01),分娩率高出14.28%(P<0.01)。结论:同期发情处理对不同胎次湖羊母羊的发情率和发情持续时间等发情指标无显著影响,产羔性能差异显著。

Objective:Comparison of reproductive performance of high and low parity ewes in estrus synchronization was made.Methods:The 14 and 12 ewes of healthy Hu sheep respectively with parity 2 and parity 6—7 weaded after 2 days were selected.According to the ovsynch regimen,the LHRH-A3 dose of 12.5μg/sheep and the PG-CL dose of 0.1 mg/sheep were done and no longer treated with the second injection of GnRH,and the PG-CL treatment was simultaneously injected with PMSG.The ram tests were done until the end of the rut.At 20 h after estrus,fresh semen was injected into the uterine neck at 12 h intervals.Results:The ewes estrus rate of diffferent parities was 100%.On the duration of estrus,PG-heat interval and designed,the Gn-end of estrus,nest lambing number and the indices such as pregnancy,there was no significant difference(P>0.05),and the estrus index data from mean difference of ewes with parity 6—7 were greater than the parity 2.The weight of second-born lambs was higher than that of 6—7 parities(P<0.01),and delivery rate was 14.28%higher(P<0.01).Conclusion:Simultaneous estrus treatment had no significant effect on estrus rate and estrus duration of estrus,but significantly affected lambing performance.