公畜
2.In the estimation of heritability, various non-genetic factors must be excluded from the variance of sire or dam.
3.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.
4.(2) QTL effect and family structure play important roles for threshold traits as same as quantitative traits, and more full-sib size could improve accuracy and precision of estimates when family size is small under full-half sib family design.

