In modern dairy breeding programmes, high contributions from foreign sires are nearly always present. Genotyping, and therefore genomic selection (GS), concern only a subpopulation of the breeding programme’s wider dairy population. These features of a breeding programme contribute in different ways to the rate of genetic gain for the wider industry. A deterministic recursive gene flow model across subpopulations of animals in a dairy industry was created to predict the commercial performance of replacement heifers and future artificial insemination bulls. Various breeding strategies were assessed by varying the reliability of breeding values, the genetic contributions from subpopulations, and the genetic trend and merit of the foreign subpopulation. A higher response in the true breeding goal measured in standard deviations (SD) of true merit (G) after 20 years of selection can be achieved when genetic contributions shift towards higher merit alternatives compared to keeping them fixed. A foreign annual genetic trend of 0.08 SD of the breeding goal, while the domestic genetic trend is 0.10 SD, results in the overall net present value of genetic gain increasing by 1.2, 2.3, and 3.4% after 20 years as the reliability of GS in the domestic population increased from 0.3 to 0.45, 0.60 and 0.75. With a foreign genetic trend of 0.10 SD, these increases are more modest; 0.9, 1.7, and 2.4%. Increasing the foreign genetic trend so that it is higher than the domestic trend erodes the benefits of increasing the reliability of domestic GS further. Having a foreign source of genetic material with a high rate of genetic progress contributes substantially to the benefits of domestic genetic progress while at the same time reducing the expected returns from investments to improve the accuracy of genomic prediction in the home country.

中文翻译：

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考虑外来父本贡献的基因组选择育种计划的遗传效益

在现代奶牛育种计划中，几乎总是有外国公牛做出的巨大贡献。基因分型和因此的基因组选择（GS）仅涉及育种计划更广泛的奶牛种群的一个子种群。育种计划的这些特征以不同的方式为更广泛的产业带来了遗传增益。建立了确定性的递归基因流模型，跨乳制品业中的动物亚群，以预测替代小母牛和未来人工授精公牛的商业表现。通过改变育种值的可靠性，亚种群的遗传贡献以及外来亚种群的遗传趋势和优点，对各种育种策略进行了评估。当遗传贡献朝着更高的择优选择（而不是固定不变）方向发展时，经过20年的选择，可以通过以择优选择的标准偏差（SD）衡量的对真正育种目标的更高反应。作为育种目标的国外年度遗传趋势为0.08 SD，而国内遗传趋势为0.10 SD，由于20年后GS的可靠性，遗传增益的总体净现值增加了1.2、2.3和3.4％。家庭人口从0.3增加到0.45、0.60和0.75。异源遗传趋势为0.10 SD时，这些增加更为适中。0.9、1.7和2.4％。增加国外遗传趋势使其高于国内遗传趋势，将侵蚀进一步提高国内GS可靠性的好处。