三河牛初生体尺和初生重遗传参数的估计

【目的】利用2000—2012年出生的5 521头三河牛的初生体尺、初生重记录，估计出生体高、体长、胸围、管围和初生重的遗传参数。【方法】使用DMU软件，采用AI-REML结合EM算法并配合多性状动物模型，以犊牛性别和母亲年龄为固定效应、出生场年月和动物个体加性遗传效应为随机效应。【结果】三河牛初生体高、体长、胸围、管围、初生重的遗传力分别为0.46、0.48、0.38、0.50和0.41，遗传相关为-0.05（管围和体长、初生重）—0.86（体长和初生重），表型相关为-0.10（体长和管围）—0.70（体长和初生重）。【结论】三河牛初生体尺、初生重的遗传力为0.38—0.50，属于高遗传力。

Genetic Parameter Estimation for Body Measurements and Weight at Birth in Sanhe Cattle

【Objective】 In this study, body measurements at birth of 5521 Sanhe cattle born from 2000 to 2012 were collected for genetic parameters estimation for height at withers, body length, chest girth and cannon circumference at birth and birth weight.【Method】DMU software was used, and AI-REML combined EM algorithm based on multiple-trait animal model was employed including sex and age of dam as fixed effects, birth herd-year-month and additive animal genetic effect as random effects.【Result】The results showed that the heritability estimates for height at withers, body length, chest girth, cannon circumference and birth weight were 0.46, 0.48, 0.38, 0.50 and 0.41, respectively. Genetic correlations among these traits varied from –0.05 (between cannon circumference and body length and birth weight, respectively) to 0.86 (body length and birth weight). Phenotypic correlations between these traits ranged from -0.10 (body length and cannon circumference) to 0.70 (body length and birth weight). 【Conclusion】 The heritability estimates were between 0.38 and 0.50 for body measurements at birth and birth weight of Sanhe cattle, which are high inheritable. These traits can be directly selected according to their breeding values, or use indirect selection on traits that are difficult to measure but genetically correlated with other traits (e.g. genetic correlation between 0.40-0.86), for further improvement of breeding efficiency and accuracy.