Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK.
Agri-Food and Biosciences Institute, Large Park, Hillsborough, BT26 6DR, UK.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae040.
Improving the feeding efficiency of dairy cows is a key component to improve the utilization of land resources and meet the demand for high-quality protein. Advances in genomic methods and omics techniques have made it possible to breed more efficient dairy cows through genomic selection. The aim of this review is to obtain a comprehensive understanding of the biological background of feed efficiency (FE) complex traits in purebred Holstein dairy cows including heritability estimate, and genetic markers, genes, and pathways participating in FE regulation mechanism. Through a literature search, we systematically reviewed the heritability estimation, molecular genetic markers, genes, biomarkers, and pathways of traits related to feeding efficiency in Holstein dairy cows. A meta-analysis based on a random-effects model was performed to combine reported heritability estimates of FE complex. The heritability of residual feed intake, dry matter intake, and energy balance was 0.20, 0.34, and 0.22, respectively, which proved that it was reasonable to include the related traits in the selection breeding program. For molecular genetic markers, a total of 13 single-nucleotide polymorphisms and copy number variance loci, associated genes, and functions were reported to be significant across populations. A total of 169 reported candidate genes were summarized on a large scale, using a higher threshold (adjusted P value < 0.05). Then, the subsequent pathway enrichment of these genes was performed. The important genes reported in the articles were included in a gene list and the gene list was enriched by gene ontology (GO):biological process (BP), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis. Three GO:BP terms and four KEGG terms were statistically significant, which mainly focused on adenosine triphosphate (ATP) synthesis, electron transport chain, and OXPHOS pathway. Among these pathways, involved genes such as ATP5MC2, NDUFA, COX7A2, UQCR, and MMP are particularly important as they were previously reported. Twenty-nine reported biological mechanisms along with involved genes were explained mainly by four biological pathways (insulin-like growth factor axis, lipid metabolism, oxidative phosphorylation pathways, tryptophan metabolism). The information from this study will be useful for future studies of genomic selection breeding and genetic structures influencing animal FE. A better understanding of the underlying biological mechanisms would be beneficial, particularly as it might address genetic antagonism.
提高奶牛的采食量效率是提高土地资源利用和满足高质量蛋白质需求的关键组成部分。基因组方法和组学技术的进步使得通过基因组选择来培育更高效的奶牛成为可能。本综述的目的是全面了解荷斯坦奶牛的饲料效率（FE）复杂性状的生物学背景，包括遗传力估计值以及参与 FE 调控机制的遗传标记、基因和途径。通过文献检索，我们系统地综述了荷斯坦奶牛采食量效率相关性状的遗传力估计值、分子遗传标记、基因、生物标志物和途径。基于随机效应模型的荟萃分析用于合并 FE 复杂性状的报道遗传力估计值。剩余采食量、干物质采食量和能量平衡的遗传力分别为 0.20、0.34 和 0.22，这证明将相关性状纳入选择育种计划是合理的。对于分子遗传标记，总共报告了 13 个单核苷酸多态性和拷贝数变异位点、相关基因和功能，这些标记在不同群体中具有显著意义。总共总结了 169 个报道的候选基因，使用了较高的阈值（调整后的 P 值<0.05）。然后，对这些基因进行了后续通路富集分析。将文献中报道的重要基因包含在一个基因列表中，并通过基因本体（GO）：生物过程（BP）和京都基因与基因组百科全书（KEGG）通路分析对基因列表进行了富集。三个 GO:BP 术语和四个 KEGG 术语具有统计学意义，主要集中在三磷酸腺苷（ATP）合成、电子传递链和 OXPHOS 途径。在这些途径中，涉及的基因，如 ATP5MC2、NDUFA、COX7A2、UQCR 和 MMP 等，尤为重要，因为它们之前已有报道。涉及基因的 29 个报道的生物学机制主要通过四个生物学途径（胰岛素样生长因子轴、脂质代谢、氧化磷酸化途径、色氨酸代谢）得到解释。本研究提供的信息将有助于未来的基因组选择育种和影响动物 FE 的遗传结构的研究。更好地了解潜在的生物学机制将是有益的，特别是因为这可能解决遗传拮抗问题。
