Genetic parameters for milk yield and litter size in Boutsico dairy sheep

Lactation and litter size records (n = 2553) of Boutsico dairy sheep were u sed to estimate direct additive, maternal genetic, maternal and animal's pe rmanent environmental variance components for milk yield and litter size by restricted maximum likelihood under a repeated records animal model. Raw m ilk yield data were transformed by log and Box-Cox (BC) transformations. He ritability estimates of direct additive effects were between 0.21 and 0.30, 0.18 and 0.24 and 0.21 and 0.27 for untransformed, log transformed and BC transformed data, respectively. Only maternal and animal's environmental ef fects were important for milk yield. Direct-maternal genetic covariance did not significantly (P > 0.05) influence milk yield. Repeatability for milk yield ranged from 0.32 to 0.38. Only additive genetic effects were importan t for litter size. Heritability and repeatability for lifter size were 0.07 and 0.11, respectively Genetic and phenotypic correlations between yield a nd litter size were 0.13 and 0.19, respectively.