Genetic analysis on body weight at different ages in broiler chicken raised in commercial environment
Genetic analysis on body weight at different ages in broiler chicken raised in commercial environment
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DOI：
10.1111/jbg.12448
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发表时间：
2019-10-17
影响因子：
2.6
通讯作者：
Jensen, Just
中科院分区：
文献类型：
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作者：
Chu, Thinh Tuan;Madsen, Per;Jensen, Just
建立了一个多变量模型，并用于估算商品化环境下1-6周龄肉仔鸡体重的遗传参数。模型的发展是基于育种值的预测能力，从交叉验证程序，依赖于半同胞相关性进行评估。多变量模型通过标准化不同地应用于男性和女性BW来解释性别之间的异质性方差。结果表明，体重的直接加性遗传方差、环境母体方差和残差方差均随日龄的增加而显著增加。方差在周龄以上的急剧增加主要是由于尺度效应。永久环境母体方差占表型方差的比例随年龄的增长而逐渐降低。不同周龄体重性状的遗传力在0.28 ~ 0.33之间。连续周体重的直接遗传效应具有较高的遗传相关（0.85-0.99），而早、晚体重的遗传相关较低（0.32-0.57）。性别间方差分量的差异随年龄的增长而增大。综上所述，从第1周到第6周，环境母体对肉鸡体重的永久性影响随日龄的增加而降低。当在模型中考虑性别间的异质性方差时，考虑性别相同方差的模型的潜在偏倚可以减少。
A multivariate model was developed and used to estimate genetic parameters of body weight (BW) at 1-6 weeks of age of broilers raised in a commercial environment. The development of model was based on the predictive ability of breeding values evaluated from a cross-validation procedure that relied on half-sib correlation. The multivariate model accounted for heterogeneous variances between sexes through standardization applied to male and female BWs differently. It was found that the direct additive genetic, permanent environmental maternal and residual variances for BW increased drastically as broilers aged. The drastic increase in variances over weeks of age was mainly due to scaling effects. The ratio of the permanent environmental maternal variance to phenotypic variance decreased gradually with increasing age. Heritability of BW traits ranged from 0.28 to 0.33 at different weeks of age. The direct genetic effects on consecutive weekly BWs had high genetic correlations (0.85-0.99), but the genetic correlations between early and late BWs were low (0.32-0.57). The difference in variance components between sexes increased with increasing age. In conclusion, the permanent environmental maternal effect on broiler chicken BW decreased with increasing age from weeks 1 to 6. Potential bias of the model that considered identical variances for sexes could be reduced when heterogeneous variances between sexes are accounted for in the model.