宁夏地区荷斯坦牛生产性状和功能性状遗传参数估计OA

[Objective]The aim of this study was to estimate the genetic parameters of main production and functional traits of Holstein cattle in Ningxia,providing a reference basis for the formulation of the genetic evaluation system and selection index of Holstein cattle in Ningxia.[Method]The culling,reproduction and production records in Holstein cattle of 9 pastures in Ningxia from 2009 to 2021 were collected.The analyzed traits included 8 production traits(daily milk production(DMY),milk fat percentage(MFP),milk protein percentage(MPP),milk lactose percentage(MLP),fat protein ratio(FPR),305 d milk yield(MY305),peak milk yield(PMY)and somatic cell score(SCS))and 3 functional traits(production life(PL),herd life(HL)and calving interval(CI)).The genetic parameters and correlations of production and functional traits of Holstein cattle in Ningxia were estimated using monotrait and bitrait animal models and the AI-REML method of DMU software.[Result]Different non-genetic factors had an extremely significant effect on the milk production traits,longevity traits and calving interval of Holstein cattle in Ningxia(P<0.01).The heritability of DMY was 0.17,while that of milk composition traits were relatively low(0.04 to 0.13).The heritability of PL and HL was both 0.08,and that of CI was 0.07,both of which were at a relatively low level.There was a positive genetic correlation(0.42 to 0.97)among milk production traits(DMY,MY305 and PMY),and a moderate positive genetic correlation between MFP and MPP(0.65),while milk production was negatively genetic correlated with MFP,MPP and SCS(―0.61 to ―0.44).Longevity traits(PL and HL)had a high genetic and phenotypic correlation(>0.80),indicating that genetic evaluation could be achieved through mutual substitution.There was a moderate negative genetic correlation between calving interval and DMY and MLP(―0.38 to ―0.33),while it was positively genetic correlated with MPP,SCS and MY305(0.31 to 0.55),suggesting a genetic antagonism between production and reproductive traits.[Conclusion]Holstein cattle population in Ningxia exhibited moderate genetic potential for production traits but relatively low heritability for udder health,reproduction and longevity.The results highlighted the necessity of incorporating functional traits into breeding objectives and developing multi-trait selection indices to achieve balanced genetic improvement for both productivity and sustainability in dairy cows.