不同品种牛超数排卵方案优化及重复超数排卵间隔期研究OA

To enhance the reproductive efficiency of elite beef and dairy cattle,accelerate genetic improvement,and support the conservation of germplasm resources,this study optimized superovulation protocols for various cattle breeds.Using Jinnan cattle,Simmental cattle,and Chinese Holstein cattle as research subjects,the study first compared the efficacy of two superovulation protocols(16-day and 21-day)in Chinese Holstein cattle and Simmental cattle.Subsequently,it explored the effects of four total doses of follicle stimulating hormone(FSH)(450,480,500,and 540 μg)on the superovulation response in Jinnan cattle.Finally,the study evaluated the impact of two different intervals(30 days and 50 days)on the performance of repeated superovulation in Jinnan cattle.The results indicated that the average total number of embryos and the average number of available embryos of Simmental cattle and Chinese Holstein cattle in the 16-day superovulation protocol were significantly higher than those in the 21-day superovulation protocol(P<0.05).For Jinnan cattle,a total FSH dose of 500 μg yielded the best results,with the average total number of embryos and transferable embryos reaching 5.86 and 4.00,respectively—both were significantly higher than those of other dosage groups(P<0.05).The evaluation of repeated superovulation intervals showed no significant decrease in the embryo yield of Jinnan cattle at intervals of 30 and 50 days(P>0.05).The results showed that the 16 d superovulation scheme is the optimal superovulation scheme for Chinese Holstein cattle and Simmental cattle.The 500 μg FSH has the best superovulation effect on Jinnan cattle and the superovulation time interval has no significant effect on embryo production.