"中原牛"种公牛精液生产性能及母牛繁殖性能OA

[Objective]To analyzes the semen production performance of"Zhongyuan cattle"(Hornless Xianan cattle)bulls and the reproductive performance of cows,identifies the advantages and constraints of its breeding system,and provides a scientific basis for optimizing breeding programs,improving seed production efficiency,and promoting industrial application.[Method]This study utilized semen production data of 8 bulls and the estrus and breeding records from 720 cows of"Zhongyuan cattle"as research subjects,and analyzed the key indicators of semen collection performance and semen yield of breeding bulls at different ages and in different seasons,as well as the reproductive performance of cows.[Result]The study found that the semen production performance of bulls was significantly affected by age and season(P<0.05).The frozen semen dose per bull at 24 months of age was 1.61 times and 1.4 times that at 16 and 18 months of age,respectively.The best production performance was observed in spring and autumn,while the worst was in summer.Semen volume and sperm concentration were not significantly affected by season(P>0.05).Analysis of six core reproductive indicators-age at puberty,estrous cycle,age at first mating,gestation period,postpartum mating interval,and calf birth weight—revealed that the average age at puberty of"Zhongyuan Cattle"cows was 382.2 d,average estrus cycle was 20.73 d,average estrus duration was 24.4 h,average age at first mating was 484.21 days,average gestation period was 284.11 d,and the average postpartum mating interval was 65.07 days.[Conclusion]The optimal semen collection window for"Zhongyuan cattle"bulls is at 24 months of age and during spring and autumn.Semen collection plans should be optimized according to differences in age and season,and cooling management should be strengthened during summer.The core indicators of female reproductive cycles have clarified the basic characteristics of the estrus rhythm in this population,which can provide a basis for precise regulation of subsequent breeding timing.Timely intervention in heifer initial breeding and postpartum mating should be implemented to improve overall seed production efficiency.