非遗传因素对安格斯牛生长和繁殖性状的影响及各性状间相关性分析OA

[Objective]This study assessed the influence of yearling weight(YW)and body condition score(BCS)on the reproductive performance of Angus cattle,thereby establishing a data-driven support system.It provides a reference for the selection and breeding of the Angus core herd and the formulation of a scientifically sound Angus cattle selection and breeding program.[Method]Data was collected and organized on two growth traits—YW and BCS,and three reproductive traits—age at first calving(AFC),age at first service(AFS),and calving interval(CI)—from six large-scale Angus cattle farms in Ningxia between 2012 and 2023.Statistical analysis was conducted using SAS software(version 9.2)to examine the effects of birth farm-year interaction and birth year-season interaction on AFC,YW,and BCS;the effects of birth site-year interaction,birth year-season interaction,breeding farm-year interaction,and breeding year-season interaction on AFS;and the effects of birth farm-year interaction,birth year-season interaction,breeding site-year interaction,breeding year-season interaction,and parity on CI.The study utilized animal models to investigate the genetic and phenotypic correlations among various traits.[Result]The results demonstrated that non-genetic factors had highly significant effects(P<0.01)on age at AFC,age at AFS,CI,YW,and BCS.The genetic correlation between AFC and AFS was moderate(0.45),with a corresponding phenotypic correlation of 0.43.Conversely,AFC exhibited a negative genetic correlation(-0.26)and phenotypic correlation(-0.22)with CI.The analysis of growth traits(BCS,YW)and reproductive traits(AFC,AFS,CI)revealed that,except for a weak positive correlation between BCS and CI(0.001)(P<0.001),all other growth traits(BCS,YW)displayed negative genetic and phenotypic correlations with reproductive traits(AFC,AFS,CI).Notably,YW showed a strong positive genetic correlation(0.83)and phenotypic correlation(0.76)with BCS.[Conclusion]In conclusion,under conditions characterized by strong environmental influences,the reproductive efficiency of Angus cattle can be enhanced by either moderating the rate of annual weight gain or by selecting early-maturing,low-body-weight cows as foundational herd parents,thereby indirectly reducing the age at first calving and the calving interval.