A sire and dam model and a sire and maternal grandsire model are fitted for weight at birth and weight at weaning of sheep to estimate the direct genetic and maternal additive genetic variances.

• 本文利用公畜母畜模型和公畜外祖父模型估计了初生重、断奶重的直接加性遗传方差、母本遗传方差和遗传参数；得出初生重的直接加性遗传效应、母本遗传效应和总的加性遗传效应的遗传力分别为:0.；164、0