The objectives of this study were to better understand the genetic architecture and the possibility of genomic evaluation for feed efficiency traits by (i) performing genome-wide association studies (GWAS), and (ii) assessing the accuracy of genomic evaluation for feed efficiency traits, using single-step genomic best linear unbiased prediction (ssGBLUP)-based methods. The analyses were performed in residual feed intake (RFI), residual body weight gain (RG), and residual intake and body weight gain (RIG) during three different fattening periods. The phenotypes from 4,578 Japanese Black steers, which were progenies of 362 progeny-tested bulls and the genotypes from the bulls were used in this study. The results of GWAS showed that a total of 16, 8, and 12 gene ontology terms were related to RFI, RG, and RIG, respectively, and the candidate genes identified in RFI and RG were involved in olfactory transduction and the phosphatidylinositol signaling system, respectively. The realized reliabilities of genomic estimated breeding values were low to moderate in the feed efficiency traits. In conclusion, ssGBLUP-based method can lead to understand some biological functions related to feed efficiency traits, even with small population with genotypes, however, an alternative strategy will be needed to enhance the reliability of genomic evaluation.

中文翻译：

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使用单步基因组最佳线性无偏预测方法对日本黑牛饲料效率性状进行全基因组关联研究和基因组评估。

本研究的目的是通过 (i) 进行全基因组关联研究 (GWAS) 和 (ii) 评估饲料效率性状基因组评估的准确性，更好地了解遗传结构和饲料效率性状基因组评估的可能性，使用基于单步基因组最佳线性无偏预测（ssGBLUP）的方法。对三个不同育肥期的残余采食量 (RFI)、残余体重增加 (RG) 以及残余采食量和体重增加 (RIG) 进行了分析。本研究使用了来自 4,578 头日本黑牛的表型，它们是 362 头经过后代测试的公牛的后代，以及来自公牛的基因型。GWAS结果显示，共有16个、8个和12个基因本体术语分别与RFI、RG和RIG相关，RFI和RG中鉴定的候选基因分别参与嗅觉转导和磷脂酰肌醇信号系统。在饲料效率性状中，基因组估计育种值的实现可靠性从低到中等。总之，基于 ssGBLUP 的方法可以理解一些与饲料效率性状相关的生物学功能，即使是具有基因型的小群体，但是，将需要一种替代策略来提高基因组评估的可靠性。