The aim of this study was to evaluate whether there are predictive advantages for breeding values with inclusion of X chromosome genomic markers for reproductive (occurrence of early pregnancy – P16 and age at first calving - AFC) and andrological (scrotal circumference -SC) variables in beef cattle. There were 3263 genotypes of females and males evaluated. There were breeding value estimates for SC, AFC and P16 considering two scenarios: 1) only autosomal markers or 2) autosomal and X chromosome markers. To evaluate effects of inclusion of X chromosome markers on selection, responses to selection were compared including or not including genomic marker information from the X chromosome. There were greater heritability estimates for SC (0.40 and 0.31), AFC (0.11 and 0.09) and P16 (0.43 and 0.38) when analyses included, compared with not including, genomic marker information from the X chromosome. When selection is based on results from analyses that did not include information for the X chromosome, there was about a 7 % lesser mean genomic breeding value for the SC traits for selected animals. For P16, there was an approximate 4% lesser breeding value without inclusion of genomic marker information from the X chromosome, while this inclusion did not have as great an effect on the breeding value for AFC. There was an average predictive correlation of 0.79, 0.98 and 0.84 for SC, AFC and P16, respectively. These estimates indicate inclusion of the X chromosome genomic marker information in the analysis can improve prediction of genomic breeding values, especially for SC.

本研究的目的是评估包含 X 染色体基因组标记的育种值是否具有预测优势，用于生殖（早期妊娠的发生 - P16 和第一次产犊年龄 - AFC）和男科（阴囊围 -SC）变量肉用牛。评估了 3263 种女性和男性的基因型。考虑到两种情况，对 SC、AFC 和 P16 进行了育种价值估计：1) 仅常染色体标记或 2) 常染色体和 X 染色体标记。为了评估包含 X 染色体标记对选择的影响，比较了对选择的反应，包括或不包括来自 X 染色体的基因组标记信息。与不包括相比，当分析包括时，SC（0.40 和 0.31）、AFC（0.11 和 0.09）和 P16（0.43 和 0.38）的遗传力估计值更高，来自 X 染色体的基因组标记信息。When selection is based on results from analyses that did not include information for the X chromosome, there was about a 7 % lesser mean genomic breeding value for the SC traits for selected animals. 对于 P16，如果不包含来自 X 染色体的基因组标记信息，育种值大约低 4%，而这种包含对 AFC 的育种值没有那么大的影响。SC、AFC 和 P16 的平均预测相关性分别为 0.79、0.98 和 0.84。这些估计表明在分析中包含 X 染色体基因组标记信息可以改进基因组育种值的预测，尤其是对于 SC。When selection is based on results from analyses that did not include information for the X chromosome, there was about a 7 % lesser mean genomic breeding value for the SC traits for selected animals. 对于 P16，如果不包含来自 X 染色体的基因组标记信息，育种值大约低 4%，而这种包含对 AFC 的育种值没有那么大的影响。SC、AFC 和 P16 的平均预测相关性分别为 0.79、0.98 和 0.84。这些估计表明在分析中包含 X 染色体基因组标记信息可以改进基因组育种值的预测，尤其是对于 SC。When selection is based on results from analyses that did not include information for the X chromosome, there was about a 7 % lesser mean genomic breeding value for the SC traits for selected animals. 对于 P16，如果不包含来自 X 染色体的基因组标记信息，育种值大约低 4%，而这种包含对 AFC 的育种值没有那么大的影响。SC、AFC 和 P16 的平均预测相关性分别为 0.79、0.98 和 0.84。这些估计表明在分析中包含 X 染色体基因组标记信息可以改进基因组育种值的预测，尤其是对于 SC。在不包含来自 X 染色体的基因组标记信息的情况下，育种值大约低 4%，而这种包含对 AFC 的育种值没有那么大的影响。SC、AFC 和 P16 的平均预测相关性分别为 0.79、0.98 和 0.84。这些估计表明在分析中包含 X 染色体基因组标记信息可以改进基因组育种值的预测，尤其是对于 SC。在不包含来自 X 染色体的基因组标记信息的情况下，育种值大约低 4%，而这种包含对 AFC 的育种值没有那么大的影响。SC、AFC 和 P16 的平均预测相关性分别为 0.79、0.98 和 0.84。这些估计表明在分析中包含 X 染色体基因组标记信息可以改进基因组育种值的预测，尤其是对于 SC。