Comparison of genetic improvement for litter size at birth by direct and indirect selection in swine herd
Comparison of genetic improvement for litter size at birth by direct and indirect selection in swine herd
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DOI：
10.1111/j.1740-0929.2006.00387.x
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发表时间：
2006-12-01
影响因子：
2
通讯作者：
Satoh, Masahiro
中科院分区：
文献类型：
--
作者：
Satoh, Masahiro
采用蒙特卡罗计算机模拟生成的数据，比较了总产仔数（TNB）、NBA和NBA +死仔数（NBD）对选择的反应，结合家庭信息和选择指数计算的选择精度和期望遗传增益，以及对选择的真实反应。只有当TNB与NBA的遗传相关接近1.0，或者TNB的遗传力值远大于NBA时，TNB对NBA的选择准确率才高于NBA。在每个家庭结构中，三种选择方法中，TNB和NBA组合选择的NBA的选择准确率普遍最高。在选择方法中，TNB的预期遗传增益最大。在最佳线性无偏预测（BLUP）选择中，NBA积累的NBA遗传增益与NBA与NBD组合积累的遗传增益趋于相似，并且在第10代时，两者的遗传增益均显著大于TNB （P < 0.001）。双性状动物模型BLUP根据有误差的遗传参数估计的累积反应与真实参数估计的累积反应相似，两者之间没有显著差异。这些结果表明，NBA或NBA和NBD的选择在NBA中比TNB获得更多的遗传改善。
Responses to selection for number of piglets born alive (NBA) by the total number of piglets born (TNB), the NBA, and the NBA plus number of piglets born dead (NBD) were compared using the accuracy of selection and expected genetic gain calculated from the selection index with family information and the real response to selection, using data generated by Monte Carlo computer simulation. The accuracy of selection for NBA selected by TNB was higher than that by NBA only if the genetic correlation between TNB and NBA was close to 1.0, or the value of heritability for the TNB was much larger than that for the NBA. The accuracy of selection for the NBA selected by the combination of the TNB and the NBA was generally highest in the three selection methods in each family structure. Selection by the TNB resulted in the greatest expected genetic gain for the TNB among the selection methods. In the best linear unbiased prediction (BLUP) selection, the genetic gain for the NBA accumulated by the NBA tended to be similar to that accumulated by the combination of the NBA and the NBD, and both genetic gains at generation 10 were significantly larger than that by the TNB (P < 0.001). The accumulated responses selected by the two-trait animal model BLUP estimated from genetic parameters with errors were similar to those estimated from the true parameters, and there was no significant difference between them. These results indicate that selection by the NBA or by the NBA and the NBD gives more genetic improvement in the NBA than that by the TNB.