用随机回归模型估计SD-Ⅱ系猪体重的遗传和表型协方差函数  

Estimating Genetic and Phenotypic Covariance Functions for Body Weight of SD-Ⅱ Swine Line

作　　者：刘文忠[1] 周忠孝[1] 张沅[2] 

机构地区：[1]山西农业大学动物科技学院,太谷030801 [2]中国农业大学动物科技学院,北京100094

出　　处：《畜牧兽医学报》2002年第2期119-123,共5页ACTA VETERINARIA ET ZOOTECHNICA SINICA

摘　　要：用6个世代的686头SD-Ⅱ系猪的生长记录估计作为经度数据的体重的遗传和表型协方差函数。配合将年龄的勒让德多项式作为自变量的随机回归模型,用平均信息约束最大似然（AIREML）法估计回归系数间的协方差,从而得到加性遗传和永久环境协方差函数的系数。结果表明,协方差函数可以反映出体重在连续的年龄尺度上的遗传和表型变异。当多项式的配合阶数k=3,即降阶配合时,便可充分描述SD-Ⅱ系猪体重的生长变化。降价配合涉及的参数较少,同时可以缓和协方差估值间的差异。Growth records of SD-Ⅱ Line for 686 pigs of 6 generations were used to estimate the genetic and phe-notypic covariance functions for body weight as longitudinal data. A random regression model with Legedre Polynomials of age as independent variables was used to estimate the covariances among the regression coefficients, thus the coefficients of genetic and permanent environmental covariance functions by restricted maximum likelihood employing the average information algorithm. The results showed that covariance functions could reflect the changes of genetic and phenotypic variation for body weight in continuous scale of age. When the order of polynomial fit k = 3, growth changes for body weight of SD-Ⅱ Line were described adequately. A reduced order fit involved less parameters and smoothes out differences in estimates of covariances.

关 键 词：SD-Ⅱ系猪 协方差函数 经度数据 约束最大似然法 随机回归模型 体重 遗传 表型 

分 类 号：S828.2[农业科学—畜牧学]