季节对杜泊羊卵泡发育及体外胚胎生产和移植的影响OA

The experiment aimed to analyze the effects of seasonal factors on the efficiency of in vitro embryo production(IVEP)in mutton sheep,providing a theoretical basis for optimizing sheep IVEP technology.Black-headed Dorper sheep were selected as donors and Mongolian sheep as recipients,while ovaries were collected from Hu sheep at a slaughterhouse.Through exogenous hormone induction treatments,the study determined the efficiency of follicular development and ovum pick-up(OPU)in Dorper sheep,oocyte recovery efficiency from Hu sheep ovaries,in vitro embryo development in Dorper sheep,as well as estrus synchronization and embryo transfer conception rates in recipient sheep across different seasons.The results indicated that:after hormone induction,season had no significant effect on follicular development in Dorper sheep(P>0.05).however,for slaughterhouse-derived Hu sheep ovaries,the mean follicle count and mean oocyte number in summer were extremely significantly lower than in other seasons(P<0.01).The average oocyte number in Dorper sheep in autumn was significantly higher than in summer(P<0.05),but the differences in usable oocyte number and cleavage rate were not significant(P>0.05).Season had no significant effect on the blastocyst rate of Dorper sheep after in vitro fertilization(P>0.05).The estrus synchronization rate of Mongolian sheep in summer was extremely significantly lower than in other seasons(P<0.01),and the conception rate of in vitro embryo transfer in winter was slightly higher than in other seasons(P>0.05).In conclusion,in the large-scale application of IVEP technology for Dorper sheep,although the total number of recovered oocytes was highest in autumn,there were no significant differences in indicators such as average follicle number,usable oocyte number,cleavage rate,blastocyst rate,and conception rate.However,summer had a significant negative impact on the oocyte number of Hu sheep and the estrus synchronization efficiency of Mongolian sheep.