利用多性状混合模型估计猪繁殖性状的遗传参数

目前在猪殖力性状的遗传评定中，应用多性状混合模型可比单性状混合模型提高遗传评定的准确度，应用多性状混合模型对丹系长白猪5个主要繁殖力性状的遗传参数进行估计分析，结果表明总产仔数，产活仔数，初生窝重，断奶活仔数及断奶窝重的遗传力分别为0.02,0.03,0.03,0.05及0．07，断奶窝重与其他4个性状之间存在在较大的遗传相关，初生窝重与产活仔数之间存在很高的遗传负相关（－0．65），因此，为了提高繁殖性状的综合选择效果，建议应用多性状混合模型进行遗传参数及育种植的估计。

Use of Multi-trait Mixed Models for Estimating Genetic Parameters of Reproductive Traits in Danish Landrace

Single trait mixed models have been dominantly utilized for genetic evaluation of the reproductive traits in swine. However, employing a multiple trait approach may lead to more accurate genetic evaluations. For 5 litter size and litter weight traits of Danish Landrace, genetic parameters were estimated using a multiple trait mixed model. The heritability estimates were 0.02, 0.03, 0.03, 0.05 and 0.07 for litter size (TNB), litter size born alive (NBA), litter weight (LW), litter size at weaning (LSW) and litter weight at weaning (LWW), respectively. Large positive environmental correlation estimates were obtained between LWW and the other four traits. There was a negative genetic correlation (-0.65) between LW and NBA. This study suggests simultaneous selection for two or more traits using multivariate mixed models is appropriate to improve overall reproductive response.