Ugarte E, Urarte E, Arrese F, Arranz J, Silio L, Rodriguez C
Departamento de Industria, Agricultura y Pesca, Agraria, Spain.
J Dairy Sci. 1996 Dec;79(12):2268-77. doi: 10.3168/jds.S0022-0302(96)76604-3.
The genetic progress attained with the breeding scheme of the blond-faced Latxa dairy sheep in the Spanish Basque Country was assessed by a Bayesian approach based on the marginal posterior distributions of parameters achieved via Gibbs sampling. The data file included 49,056 milk yield records of 22,363 ewes. Normal distributions were assumed for EBV and fixed effects, and scaled inverted chi-square distributions were assumed for variance components or additive, permanent environment, and residual effects. Under vague priors for variance components, the posterior means (SD) for heritability and permanent environment coefficient for milk yield at 120 d were 0.22(0.01) and 0.20(0.01). An important effect on the milk yield (41.6% of the mean) was evident for a genetic group of imported rams. Selection was effective for sheep that were bred by AI and that had known parents. The robustness of results for effect of genetic group and genetic trends was validated using a mildly informative prior constructed from variance components estimated with the related black-faced Latxa breed.
通过基于吉布斯抽样获得的参数边际后验分布的贝叶斯方法，评估了西班牙巴斯克地区金脸拉特萨奶羊育种方案所取得的遗传进展。数据文件包含22363只母羊的49056条产奶量记录。假定估计育种值（EBV）和固定效应服从正态分布，假定方差分量或加性、永久环境和残差效应服从尺度化逆卡方分布。在方差分量的模糊先验条件下，120日龄产奶量的遗传力和永久环境系数的后验均值（标准差）分别为0.22（0.01）和0.20（0.01）。对于一个进口公羊的遗传群体，对产奶量有显著影响（占均值的41.6%）。选择对通过人工授精繁殖且有已知亲本的绵羊是有效的。利用从相关黑脸拉特萨品种估计的方差分量构建的适度信息先验，验证了遗传群体效应和遗传趋势结果的稳健性。
