杜洛克、长白、大约克猪生长和肉用性状的杂交参数估计

采用Dickerson(1973)模型，用加权最小二乘分析估计了杜洛克（杜）、长白（长）、大约克（大）猪的杂交参数。结果表明，3个亲本品种在生长和肉用性状上存在明显的遗传差异。生长和肉用性状的母本遗传效应较小（失水率、大理石纹等级、贮存损失例外）。胴体体尺性状个体杂优值较小，但日增重和料肉比的个体杂优估值高。母本杂优效应对于日增重、料肉比、胴体比例、失水率、肉色等级、贮存损失和背膘厚具有一定的重要性。正反交差异表明，大约克×长白比长白×大约克更利于生长和肉用性能提高。

Estimation of Crossbreeding Parameters of Growth and Meat Production Traits in Crosses of Duroc,Landrace and Large Yorkshire

Crossing parameters were estimated for crosses of Duroc, Landrace and Large Yorkshire through weighted least square analysis with the Dickerson (1973) model. The results revealed that large genetic differences existed in traits of growth and meat production among parental breeds. Maternal genetic effects, however, were not important for these traits with excepts of drip loss, marbling score and storage loss. Individual heterosis was of no importance regarding carcass measurements, but found to have large effects on daily gain and feed conversion. Disagreement in individual heterosis estimates with literature could be attributed to varied assessing approaches. Estimates of maternal heterosis were important for daily gain, feed conversion, carcass composition, drip loss percentage, meat color score, storage loss and backfat thickness. Reciprocal differences that were detected in growth and meat production traits suggested the superiority of crossing Large Yorkshire sires with Landrace dams over its reverse combination.