Meirelles S L C, Mokry F B, Espasandín A C, Dias M A D, Baena M M, de A Regitano L C
Departamento de Zootecnia, Universidade Federal de Lavras, Lavras, MG, Brasil.
Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brasil.
Genet Mol Res. 2016 Jun 10;15(2):gmr7471. doi: 10.4238/gmr.15027471.
Correlation between genetic parameters and factors such as backfat thickness (BFT), rib eye area (REA), and body weight (BW) were estimated for Canchim beef cattle raised in natural pastures of Brazil. Data from 1648 animals were analyzed using multi-trait (BFT, REA, and BW) animal models by the Bayesian approach. This model included the effects of contemporary group, age, and individual heterozygosity as covariates. In addition, direct additive genetic and random residual effects were also analyzed. Heritability estimated for BFT (0.16), REA (0.50), and BW (0.44) indicated their potential for genetic improvements and response to selection processes. Furthermore, genetic correlations between BW and the remaining traits were high (P > 0.50), suggesting that selection for BW could improve REA and BFT. On the other hand, genetic correlation between BFT and REA was low (P = 0.39 ± 0.17), and included considerable variations, suggesting that these traits can be jointly included as selection criteria without influencing each other. We found that REA and BFT responded to the selection processes, as measured by ultrasound. Therefore, selection for yearling weight results in changes in REA and BFT.
对巴西天然牧场饲养的坎辛牛肉牛的遗传参数与背膘厚度（BFT）、眼肌面积（REA）和体重（BW）等因素之间的相关性进行了估计。使用贝叶斯方法通过多性状（BFT、REA和BW）动物模型对1648头动物的数据进行了分析。该模型包括当代组、年龄和个体杂合度作为协变量的影响。此外，还分析了直接加性遗传效应和随机残差效应。BFT（0.16）、REA（0.50）和BW（0.44）的遗传力估计表明了它们在遗传改良和对选择过程反应方面的潜力。此外，BW与其余性状之间的遗传相关性较高（P>0.50），表明对BW的选择可以改善REA和BFT。另一方面，BFT与REA之间的遗传相关性较低（P = 0.39±0.17），且存在相当大的变异，表明这些性状可以共同作为选择标准而互不影响。我们发现，通过超声测量，REA和BFT对选择过程有反应。因此，对周岁体重的选择会导致REA和BFT的变化。
