• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of dairy science >Genetic analysis of calving traits by the multi-trait individual animal model
【24h】

Genetic analysis of calving traits by the multi-trait individual animal model

机译：用多性状个体动物模型对产犊性状进行遗传分析

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Five alternative models were applied for analysis of dystocia and stillbirth in first and second parities. Models 1 and 2 were included only to estimate the parameters required for model 4, and models 3 and 5 are included only as comparisons to the model 4 estimates. Variance components were estimated by multi-trait REML, including cows with valid calving records for both parities. For the effects of sire of calf on first and second parities, variance components were estimated including only calvings with the same sire of calf for both parities. All heritabilities for the cow effect were quite low, but higher for dystocia than for stillbirth and higher in first parity. The sire-of-calf heritabilities were higher than the cow effect heritabilities, except for stillbirth in parity 2. Unlike the effect of cow correlations, all sire of calf correlations were ＞0.6, and the correlations for the same trait in parities 1 and 2 were ＞0.9. Thus, a multi-trait analysis should yield a significant gain in accuracy with respect to the sire of calf effects for bulls not mated to virgin heifers. A multi-trait individual animal model algorithm was developed for joint analysis of dystocia and stillbirth in first and second parities. Relationships matrices were included both for the effects of cow and sire of calf. In addition, random herd-year-season and fixed sex of calf effects were included in the model. Records were pre-adjusted for calving month and age. A total of 899,223 Israeli Holstein cows with first calvings since 1985 were included in the complete analysis. Approximate reliabilities were computed for both sire of cow and sire of calf effects. Correlations between these reliabilities and reliabilities obtained by direct inversion of the coefficient matrix for a sire of cow-sire of calf model were all close to 0.99. Phenotypic trends for cows born from 1983 through 2007 were economically unfavorable for dystocia and favorable for stillbirth in both parities. Genetic trends were economically unfavorable for both dystocia and stillbirth in first parity. First-parity sire of calf trends were unfavorable for dystocia, but favorable for stillbirth. All environmental trends were nearly zero. Regressions of evaluations of the complete analysis on a model including only calvings before 2011 were all ＞0.8. All evaluations met the Interbull Method 3 criterion for unbiasedness. Model 4, which computed genetic evaluations for all animals for all 4 traits accounting for all known relationships and correlations among the traits, is recommended for routine genetic evaluation of calving traits.
机译：五个替代模型被用于分析第一胎和第二胎的难产和死产。包括模型1和2仅用于估计模型4所需的参数，而包括模型3和5仅作为与模型4估计的比较。方差成分是通过多特征REML估算的，包括对两个胎均具有有效产犊记录的母牛。对于小牛父本对第一胎和第二胎的影响，估算方差分量，仅包括两个胎均具有相同小牛父本的犊牛。母牛效应的所有遗传力都非常低，但是难产要比死产要高，而胎次要高。犊牛的遗传力比母牛效应的遗传力要高，除了胎次为2的死胎。与母牛的相关性不同，所有犊牛的遗传力都大于0.6，同等性状在1和2中的相关性＞ 0.9。因此，对于不与原始小母牛交配的公牛而言，多性状分析应在犊牛效应的父亲方面提高准确性。开发了一种多特征个体动物模型算法，用于对第一胎和第二胎的难产和死胎进行联合分析。关系矩阵包括牛和小牛的影响。此外，模型中包括随机的牧群年季节和固定的犊牛性别。记录已针对产犊月份和年龄进行了预先调整。完整分析中总共包括899,223例自1985年以来首次产犊的以色列荷斯坦奶牛。计算母牛的父亲和小牛影响的父亲的近似可靠性。这些可靠性与通过对牛犊的一头小牛模型的系数矩阵直接求逆获得的可靠性之间的相关性均接近0.99。从经济上看，1983年至2007年出生的母牛的表型趋向对难产和两胎的死产都有利。难产和死胎的遗传趋势在经济上都是不利的。犊牛趋势的第一胎父亲对难产不利，但对死胎有利。所有环境趋势几乎为零。对仅包括产犊之前的产犊的模型进行的全面分析评估的回归均大于0.8。所有评估均符合Interbull方法3的无偏标准。建议将模型4计算出所有4种性状对所有动物的遗传评估，考虑到这些性状之间的所有已知关系和相关性，建议对产犊性状进行常规遗传评估。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号