Genomic estimated breeding values (GEBV) by single-step genomic BLUP (ssGBLUP) are affected by the centering of marker information used. The use of a fixed effect called J factor will lead to GEBV that are unaffected by the centering used. We extended the use of a single J factor to a group of J factors. J factor(s) are usually included in mixed model equations (MME) as regression effects but a transformation similar to that regularly used for genetic groups can be applied to obtain a simpler MME, which is sparser than the original MME and does not need computation of the J factors. When the J factor is based on the same structure as the genetic groups, then MME can be transformed such that coefficients for the genetic groups no longer include information from the genomic relationship matrix. We illustrate the use of J factors in the analysis of a Red dairy cattle data set for fertility. The GEBV from these analyses confirmed the theoretical derivations that show that the resulting GEBV are allele coding independent when a J factor is used. Transformed MME led to faster computing time than the original regression-based MME.

中文翻译：

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具有遗传组的单步基因组 BLUP 和等位基因编码的自动调整

单步基因组 BLUP (ssGBLUP) 的基因组估计育种值 (GEBV) 受所用标记信息的居中影响。使用称为 J 因子的固定效应将导致 GEBV 不受所使用的居中影响。我们将单个 J 因子的使用扩展到一组 J 因子。J 因子通常作为回归效应包含在混合模型方程 (MME) 中，但可以应用类似于常规用于遗传组的变换来获得更简单的 MME，它比原始 MME 更稀疏且不需要计算J 因子。当 J 因子基于与遗传组相同的结构时，可以转换 MME，使得遗传组的系数不再包括来自基因组关系矩阵的信息。我们说明了在分析红色奶牛生育力数据集时使用 J 因子。来自这些分析的 GEBV 证实了理论推导表明，当使用 J 因子时，所得的 GEBV 是独立的等位基因编码。转换后的 MME 比原来的基于回归的 MME 计算时间更快。