基于动物模型BLUP的杜洛克猪生长及繁殖性状选择进展

Selection Responses of Growth and Reproductive Traits in Duroc Pigs Based on Animal Model BLUP

【目的】揭示基于动物模型最佳线性无偏预测(animal model best linear unbiased prediction,AM-BLUP)的选择指数对杜洛克猪生长及繁殖性状的选育效果。【方法】在采用AM-BLUP方法估计个体目标性状育种值基础上,以达100 kg体质量日龄(相对权重0.7)和100 kg活体背膘厚(相对权重0.3)为主选性状构建选择指数,对1个闭锁的杜洛克猪群开展持续7年(2013—2019年)的选育,系统分析选育期间猪群6个生长及繁殖性状表型值、估计育种值(estimated breeding value,EBV)、选择指数及近交系数的变化。【结果】相较于2013年,2019年猪群达100 kg体质量日龄、100 kg活体背膘厚和30~100 kg料重比分别极显著缩短4.45 d、降低0.52 mm和降低0.05(P<0.01);初产和经产母猪的总产仔数分别提高0.99头(P<0.05)和1.02头(P>0.05),产活仔数分别提高0.72头和0.49头(P>0.05),21日龄窝重分别降低0.39 kg和提高6.20 kg(P>0.05);主选性状达100 kg体质量日龄和100 kg活体背膘厚的EBV分别极显著降低3.447和0.533(P<0.01),选择指数极显著提高23.62(P<0.01),除30~100 kg料重比外,其余辅选性状的EBV均获得了不同程度改进。选育结束时,群体平均近交系数为3.1973%,年均增量为0.4904%。【结论】基于AM-BLUP的指数选择可有效改良猪的生产性状,但不同性状的具体选择进展会因其遗传特性的不同而异。

[Purpose]To investigate the effect of selection index based on animal model best linear unbiased prediction(AM-BLUP)for growth and reproductive traits in Duroc pigs.[Methods]From year 2013 to 2019,a closed herd of Duroc pigs had been selected continuously on an index of two main selected traits,age to 100 kg body weight(AGE,relative weight 0.7)and backfat thickness at 100 kg live weight(BF,relative weight 0.3),based on the estimated breeding value(EBV)by AMBLUP.The dynamic changes of phenotypic values,EBV of six growth and reproductive traits,selection indexes and inbreeding coefficients of the herd during the breeding period were analyzed systematically.[Results]Compared the year 2019 with 2013,the phenotypic values of AGE,BF and feed conversion rate during 30-100 kg(FCR)extremely significantly decreased 4.45 days,0.52 mm and 0.05(P<0.01),respectively;for the sows of first and latter parities,total number born increased 0.99(P<0.05)and 1.02(P>0.05),number born alive increased 0.72 and 0.49(P>0.05),litter weight at 21 days decreased 0.39 kg and increased 6.20 kg(P>0.05),respectively;the EBVs of the two main selected traits,AGE and BF extremely significantly decreased 3.447 and 0.533(P<0.01),and the selection index extremely significantly increased 23.62(P<0.01);the EBVs of other secondary selection traits were all improved in varying degrees except FCR.At the end of selection,the average inbreeding coefficient of the herd was 3.1973%,with increment 0.4904%per year.[Conclusion]The index selection based on AM-BLUP can improve production traits for pigs,but the specific selection responses may be various for the traits with different genetic characteristics.