Graduate School of Science and Technology, Niigata University, Nishi, Niigata, Japan.
Anim Sci J. 2009 Oct;80(5):491-7. doi: 10.1111/j.1740-0929.2009.00675.x.
The genetic evaluation using the carcass field data in Japanese Black cattle has been carried out employing an animal model, implementing the restricted maximum likelihood (REML) estimation of additive genetic and residual variances. Because of rapidly increasing volumes of the official data sets and therefore larger memory spaces required, an alternative approach like the REML estimation could be useful. The purpose of this study was to investigate Gibbs sampling conditions for the single-trait variance component estimation using the carcass field data. As prior distributions, uniform and normal distributions and independent scaled inverted chi-square distributions were used for macro-environmental effects, breeding values, and the variance components, respectively. Using the data sets of different sizes, the influences of Gibbs chain length and thinning interval were investigated, after the burn-in period was determined using the coupling method. As would be expected, the chain lengths had obviously larger effects on the posterior means than those of thinning intervals. The posterior means calculated using every 10th sample from 90,000 of samples after 10,000 samples discarded as burn-in period were all considered to be reasonably comparable to the corresponding estimates by REML.
利用动物模型，对日本黑牛的胴体田间数据进行了遗传评估，采用了限制最大似然（REML）估计加性遗传和残差方差。由于官方数据集的数量迅速增加，因此需要更大的内存空间，类似 REML 估计的替代方法可能会很有用。本研究的目的是研究使用胴体田间数据进行单性状方差分量估计的 Gibbs 抽样条件。作为先验分布，分别为宏观环境效应、育种值和方差分量使用均匀分布、正态分布和独立缩放的逆卡方分布。使用不同大小的数据集，在确定了使用耦合方法的预热期后，研究了 Gibbs 链长度和稀疏间隔的影响。正如预期的那样，链长度对后验均值的影响明显大于稀疏间隔的影响。在前 10000 个样本中，每隔 10000 个样本丢弃 10000 个样本作为预热期，从 90000 个样本中提取的每 10 个样本计算的后验均值，都被认为与 REML 的相应估计值相当可比。
