Ojo Ayooluwa O, Campos Gabriel S, Mulim Henrique A, Garcia Andre, Schinckel Allan P, Duff Christian, Miller Stephen P, Retallick-Riley Kelli, Oliveira Hinayah R
Department of Animal Sciences, Purdue University, West Lafayette, IN, USA.
Angus Genetics Inc., American Angus Association, St Joseph, MO, USA.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skaf212.
Mature cow size can be effectively controlled through genetic selection. Understanding the genetic relationships between mature cow weight (MWT), mature cow height (MHT), and body condition score (BCS) is essential for implementing effective selection programs to enhance cow efficiency. The objectives of this study were to 1) estimate variance components and genetic parameters for MWT, MHT, and BCS measured in the United States and Australia; 2) estimate the genetic correlation between these traits and early growth and carcass traits; and 3) estimate the genetic correlations among these traits across the two countries. The dataset provided by the American Angus Association comprised of 434,746; 213,875; and 382,156 records for MWT, MHT, and BCS, respectively. The dataset provided by Angus Australia comprised of 206,003; 15,379; and 36,184 records for MWT, MHT, and BCS, respectively. Single-trait repeatability models were used to estimate heritabilities and multiple-trait models were used to estimate genetic correlations between traits and across countries. Heritabilities (SE) for MWT were 0.45 (0.005) and 0.40 (0.006); for MHT 0.57 (0.006) and 0.63 (0.02); and for BCS 0.18 (0.004) and 0.18 (0.01), in the United States and Australia, respectively, highlighting their moderate-to-high genetic control. Genetic correlations within the United States and Australian datasets between MWT and MHT, and MWT and BCS were >0.50, and <0.20 between MHT and BCS. Genetic correlations between MWT, MHT and early growth traits were generally positive and moderate-to-high, ranging from 0.51(0.01) to 0.92(0.003) in the United States and 0.41(0.03) to 0.79(0.05) in Australia. Genetic correlations between BCS and early growth traits were in general positive (<0.30), while genetic correlations between mature cow traits and ultrasound traits ranged from strong positive to strong negative. Genetic correlations between the traits in the two countries were high for MWT = 0.91 (0.02) and MHT = 0.97 (0.02); and moderate for BCS = 0.65 (0.08). Our results suggest that optimizing selection for mature cow traits is feasible, and that a joint evaluation between the United States and Australia could be beneficial.
通过基因选择可以有效控制成年母牛的体型。了解成年母牛体重（MWT）、成年母牛身高（MHT）和体况评分（BCS）之间的遗传关系，对于实施有效的选择计划以提高母牛生产效率至关重要。本研究的目的是：1）估计在美国和澳大利亚测量的MWT、MHT和BCS的方差成分和遗传参数；2）估计这些性状与早期生长和胴体性状之间的遗传相关性；3）估计这两个国家这些性状之间的遗传相关性。美国安格斯协会提供的数据集分别包含434,746条、213,875条和382,156条MWT、MHT和BCS记录。澳大利亚安格斯协会提供的数据集分别包含206,003条、15,379条和36,184条MWT、MHT和BCS记录。单性状重复性模型用于估计遗传力，多性状模型用于估计性状之间以及不同国家之间的遗传相关性。在美国和澳大利亚，MWT的遗传力（标准误）分别为0.45（0.005）和0.40（0.006）；MHT的遗传力分别为0.57（0.006）和0.63（0.02）；BCS的遗传力分别为0.18（0.004）和0.18（0.01），突出了它们的中到高遗传控制水平。在美国和澳大利亚的数据集中，MWT与MHT以及MWT与BCS之间的遗传相关性>0.50，而MHT与BCS之间的遗传相关性<0.20。MWT、MHT与早期生长性状之间的遗传相关性通常为正且中到高，在美国范围从0.51（0.01）到0.92（0.003），在澳大利亚范围从0.41（0.03）到0.79（0.05）。BCS与早期生长性状之间的遗传相关性一般为正（<0.30），而成年母牛性状与超声性状之间的遗传相关性范围从强正到强负。两国之间性状的遗传相关性对于MWT为0.91（0.02）、对于MHT为0.97（0.02）较高；对于BCS为0.65（0.08）中等。我们的结果表明，优化成年母牛性状的选择是可行的，并且美国和澳大利亚之间的联合评估可能会有益。
