在这项研究中,六个不同的动物模型,采用约束极大似然法对鲁中肉羊早期生长性状的遗传参数和遗传趋势进行了评价。本研究的实验数据包括新生儿体重(BWT,N=2464),断奶重量(WWT,N=2923),6月龄时的体重(6WT,N=2428),从出生到断奶的平均每日体重增加(ADG1,N=2424),鲁中肉羊断奶至6月龄(ADG2,N=1836)日平均增重(2015~2019)。采用Akaike信息准则(AIC)和似然比检验(LRT)方法,确定鲁中肉羊5个性状遗传参数的最佳模型为模型4,其中BWT的直接遗传力的估计值,WWT,6WT,ADG1和ADG2分别为0.156±0.057、0.547±0.031、0.653±0.031、0.531±0.035和0.052±0.046,母本遗传力分别为0.201±0.100、0.280±0.047、0.197±0.053、0.275±0.052和0.081±0.092。ADG2和WWT之间的遗传相关性为负,其余性状之间的遗传和表型相关性均为正相关。在这项研究中,母性效应对鲁中肉羊早期生长性状的影响更为显著。总之,为了有效提高遗传参数估计的准确性,必须充分考虑产妇的影响,以确保更准确和更好的育种计划。
In this study, six different animal models were fitted, and the constrained maximum likelihood method was used to assess the genetic parameters and genetic trends of early growth traits in Luzhong mutton sheep. The experimental data of this study included the newborn weight (BWT, N = 2464), weaning weight (WWT, N = 2923), weight at 6 months of age (6WT, N = 2428), average daily weight gain from birth to weaning (ADG1, N = 2424), and average daily weight gain from weaning to 6 months of age (ADG2, N = 1836) in Luzhong mutton sheep (2015~2019). The best model for the genetic parameters of the five traits in Luzhong mutton sheep was identified as Model 4 using the Akaike information criterion (AIC) and likelihood ratio test (LRT) methods, in which the estimated values of direct heritability for the BWT, WWT, 6WT, ADG1, and ADG2 were 0.156 ± 0.057, 0.547 ± 0.031, 0.653 ± 0.031, 0.531 ± 0.035, and 0.052 ± 0.046, respectively, and the values for maternal heritability were 0.201 ± 0.100, 0.280 ± 0.047, 0.197 ± 0.053, 0.275 ± 0.052, and 0.081 ± 0.092, respectively. The genetic correlation between the ADG2 and WWT was negative, and the genetic and phenotypic correlations among the remaining traits were positive. In this study, maternal effects had a more significant influence on early growth traits in Luzhong mutton sheep. In conclusion, to effectively improve the accuracy of genetic parameter estimation, maternal effects must be fully considered to ensure more accurate and better breeding planning.