Fernández A, Rodrigáñez J, Toro M A, Rodríguez M C, Silió L
Departamento de Mejora Genética Animal, INIA, Madrid, Spain.
J Anim Sci. 2002 Sep;80(9):2267-75. doi: 10.2527/2002.8092267x.
The growth performance of inbred pigs coming from full-sib matings was compared to that of contemporary animals coming from the same sires mated to control dams. The animals belong to three strains of Iberian pigs with different histories of previous inbreeding. The data consisted of 1,615 weight records between 50 and 250 d of age from 229 pigs. The statistical model assumed the two parameters that describe the linear growth function (a = intercept, b = slope) as different traits (weight at 120 d and daily gain) and the analysis was carried out in a Bayesian framework via Gibbs sampling. The means of the posterior distribution of heritabilities, common litter environmental coefficients, and genetic correlation were 0.328 (h(2)a), 0.332 (h2b), 0.084 (c(2)a), 0.060 (c(2)b) and 0.973 (rhoG). Inbreeding depression, expressed as the performance decrease relative to the mean, per 10% increase of the inbreeding coefficient, was -3.18, -2.31 and -5.37% for weight at 120 d (a), and -3.16, -2.08 and -6.49% for daily gain (b) in each of the three strains. The results indicate that the inbreeding effects are dependent on the level of previous inbreeding, the more previous inbreeding, the less inbreeding depression.
将全同胞交配产生的近交猪的生长性能与同一公猪与对照母猪交配产生的当代动物的生长性能进行了比较。这些动物属于三个具有不同近交历史的伊比利亚猪品系。数据包括来自229头猪的1615条50至250日龄的体重记录。统计模型将描述线性生长函数的两个参数（a = 截距，b = 斜率）视为不同性状（120日龄体重和日增重），并通过吉布斯抽样在贝叶斯框架下进行分析。遗传力、共同窝环境系数和遗传相关性的后验分布均值分别为0.328（h(2)a）、0.332（h2b）、0.084（c(2)a）、0.060（c(2)b）和0.973（rhoG）。近交衰退表示为近交系数每增加10%相对于均值的性能下降，在三个品系中，120日龄体重（a）分别为-3.18%、-2.31%和-5.37%，日增重（b）分别为-3.16%、-2.08%和-6.49%。结果表明，近交效应取决于先前的近交水平，先前近交越多，近交衰退越小。
