我国杜洛克、长白、大白猪区域性联合遗传评估研究

The Regional Joint Genetic Evaluation of Duroc,Landrace and Yorkshire Pigs in China

旨在根据我国杜洛克、长白和大白猪3个品种的场间遗传联系情况进行区域性跨场联合遗传评估,为全国联合遗传评估奠定基础。本研究利用杜洛克、长白和大白3个猪种分别在9个遗传关联组共39家国家生猪核心育种场2011-2016年的生长性状数据126 070条、187 975条和491 350条,繁殖性状数据36 542、78 409条、195 031条。生长性状包括达100 kg体重日龄(age to 100 kg,AGE)、100 kg活体背膘厚(backfat to 100 kg,BF),繁殖性状为总产仔数(total number born,TNB)。遗传参数和育种值分别采用约束极大似然方法(restricted maximum likelihood,REML)和最佳线性无偏预测法(best linear unbiased prediction,BLUP)进行估计。结果表明,区域性联合遗传评估的遗传力比单场评估更准确,同样,跨场联合评估育种值估计的准确性要高于单场遗传评估。杜洛克、长白、大白猪AGE联合评估的平均准确性比单场评估分别提高了20. 9%、11. 9%、17. 3%; BF联合评估的平均准确性比单场评估分别提高了21. 3%、16. 3%、21. 0%; TNB联合评估的平均准确性比单场评估分别提高了31. 2%、14. 4%、6. 6%。联合评估后群体规模变大,遗传变异增大,个体育种值估计准确性提高,有助于联合育种。因此,我国开展杜洛克、长白和大白猪3个品种的区域性联合遗传评估是可行的。

The objective of this study was to investigate the plausibility of joint genetic evaluation in Duroc,Landrace and Yorkshire pigs in China.According to the genetic connectedness,a total of9genetic connectedness groups consisting of39national nucleus breeding farms from3pig breeds were established,respectively.The phenotypic data related to the growth and reproduction traits from2011to2016were collected.In total,126070,187975and491350records of the age to100kg(AGE)and backfat to100kg(BF),36542,78409and195031records of total number born(TNB)were analyzed for Duroc,Landrace and Yorkshire pigs,respectively.The genetic parameters and breeding values for single herd and each genetic connectedness group were estimated by REML and BLUP,respectively.The results showed that the heritabilities estimated by joint genetic evaluation were more accurate than single-herd evaluation.Similarly,the accuracy of the estimated breeding value(EBV)was improved as well.Compared to single-herd evaluation,the average accuracies of EBV obtained by joint genetic evaluation for Duroc,Landrace and Yorkshire pigs were increased by20.9%,11.9%and17.3%for AGE,21.3%,16.3%,21.0%for BF,and31.2%,14.4%,6.6%for TNB,respectively.With the joint genetic evaluation,the population size of breeding herd was increased,and the genetic variation was enlarged,resulting in the improvement of accuracy of EBV.Therefore,the joint genetic evaluation for genetic connectedness groups in Duroc,Landrace and Yorkshire pigs in China is feasible.