Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Teagasc Grange, Dunsany, Co. Meath C15 PW93, Ireland.
Irish Cattle Breeding Federation, Highfield House, Shinagh, Bandon, Co. Cork, Ireland.
Animal. 2021 Jan;15(1):100011. doi: 10.1016/j.animal.2020.100011. Epub 2020 Dec 10.
Genomic selection has proven effective for advancing genetic gain for key profit traits in dairy cattle production systems. However, its impact to-date on genetic improvement programs for beef cattle has been less effective. Despite this, the technology is thought to be particularly useful for low heritability traits such as those associated with reproductive efficiency. The objective of this study was to identify genetic variants associated with key determinants of reproductive and overall productive efficiency in beef cows. The analysis employed a large dataset derived from the national genetic evaluation program in Ireland for two of the most predominant beef breeds, viz. Charolais (n = 5 244 cows) and Limousin (n = 7 304 cows). Single nucleotide polymorphisms (SNPs) were identified as being statistically significantly associated (adj. P < 0.05) with both reproductive and productive traits for both breed types. However, there was little across breed commonality, with only two SNPs (rs110240246 and rs110344317; adj. P < 0.05) located within the genomic regions of the LCORL and MSTN genes respectively, identified in both Charolais and Limousin populations, associated with traits including carcass weight, cull-cow weight and live-weight. Significant SNPs within the MSTN gene were also associated with both reproduction and production related traits within each breed. Finally, traits including calving difficulty, calf mortality and calving interval were associated with SNPs within genomic regions comprising genes involved in cellular growth and lipid metabolism. Genetic variants identified as associated with both important reproductive efficiency and production related traits from this study warrant further analyses for their potential incorporation into breeding programmes to support the sustainability of beef cattle production.
基因组选择已被证明可有效提高奶牛生产系统中关键盈利性状的遗传增益。然而，其对肉牛遗传改良计划的影响迄今为止效果不佳。尽管如此，该技术被认为特别适用于低遗传力性状，例如与繁殖效率相关的性状。本研究的目的是鉴定与肉牛繁殖和整体生产效率的关键决定因素相关的遗传变异。该分析利用了来自爱尔兰国家遗传评估计划的一个大型数据集，该数据集来自两个最主要的肉牛品种，即夏洛来牛（n=5244 头母牛）和利木赞牛（n=7304 头母牛）。单核苷酸多态性（SNP）被确定与两个品种的繁殖和生产性状均存在统计学显著关联（adj. P < 0.05）。然而，品种间的共同性很小，只有两个 SNP（rs110240246 和 rs110344317；adj. P < 0.05）分别位于 LCORL 和 MSTN 基因的基因组区域内，在夏洛来牛和利木赞牛群体中均被鉴定出与 carcass weight、cull-cow weight 和 live-weight 等性状相关。MSTN 基因内的显著 SNP 也与每个品种内的繁殖和生产相关性状相关。最后，包括难产、犊牛死亡率和产犊间隔在内的性状与涉及细胞生长和脂质代谢的基因的基因组区域内的 SNP 相关。本研究中鉴定出的与重要繁殖效率和生产相关性状相关的遗传变异值得进一步分析，以评估其在支持肉牛生产可持续性的育种计划中的潜在应用。
