Debre Birhan Agricultural Research Center, Debre Birhan, Ethiopia.
International Centre for Agricultural Research in the Dry Areas (ICARDA), Addis Ababa, Ethiopia.
Trop Anim Health Prod. 2024 Sep 20;56(8):264. doi: 10.1007/s11250-024-04170-0.
The study was carried out to estimate genetic and phenotypic parameters for growth traits in Dorper crossbred sheep. The data set consisted of 5717 growth records from 1347 individuals of Dorper 50% crossbred sheep descended from 43 sires and 344 dams born between the years 2012 and 2022 at Debre Birhan Agricultural Research Center sheep research station, Ethiopia. Studied traits were birth weight (WT0), weaning weight (WT3), six months weight (WT6), yearling weight (WT12), average daily gain from birth to weaning (ADG1), average daily gain from weaning to six months (ADG2), average daily gain from six months to yearling (ADG3). The (co)variance components were estimated by fitting six different univariate animal models using Average Information Restricted Maximum Likelihood (AI-REML) procedure. Contrary to the genetic trend, phenotypic performance for all studied traits showed a declining trend over the years. Direct heritability estimates of 0.10 ± 0.06, 0.29 ± 0.09, 0.37 ± 0.10, 0.10 ± 0.09, 0.43 ± 0.15, 0.04 ± 0.05, and 0.14 ± 0.09 were obtained for WT0, WT3, WT6, WT12, ADG1, ADG2 and ADG3, respectively. Genetic correlations among the studied traits ranged from -0.43 (between ADG2 and ADG3) to 0.99 (between WT3 and ADG1). Selection for weaning, six months and pre-weaning average daily gain would be expected to yield good response as these traits were found moderately heritable. Strong to moderate genetic correlation of WT3 with WT6, WT12, and ADG1 suggested that selection based on WT3 would result in improvement of other growth traits due to correlated response.
本研究旨在估计多伯杂交羊生长性状的遗传和表型参数。数据集由 1347 只多伯 50%杂交羊的 5717 个生长记录组成，这些个体来自 2012 年至 2022 年期间在埃塞俄比亚德布雷伯翰农业研究中心绵羊研究站出生的 43 只公羊和 344 只母羊。研究的性状包括初生重（WT0）、断奶重（WT3）、6 月龄重（WT6）、12 月龄重（WT12）、初生至断奶日增重（ADG1）、断奶至 6 月龄日增重（ADG2）和 6 月龄至 12 月龄日增重（ADG3）。利用平均信息限制最大似然法（AI-REML）程序，通过拟合六种不同的单变量动物模型来估计（协）方差分量。与遗传趋势相反，所有研究性状的表型表现均呈现出逐年下降的趋势。WT0、WT3、WT6、WT12、ADG1、ADG2 和 ADG3 的直接遗传力估计值分别为 0.10±0.06、0.29±0.09、0.37±0.10、0.10±0.09、0.43±0.15、0.04±0.05 和 0.14±0.09。研究性状之间的遗传相关系数范围为-0.43（ADG2 和 ADG3 之间）至 0.99（WT3 和 ADG1 之间）。对断奶重、6 月龄重和育肥前期日增重进行选择预计会产生良好的反应，因为这些性状具有中度遗传力。WT3 与 WT6、WT12 和 ADG1 之间存在较强至中度遗传相关，表明基于 WT3 的选择将导致其他生长性状的改良，因为存在相关反应。
