Genetic parameters for direct and maternal effects on birth weight of garole sheep

A study was conducted to estimate the (co)variance components and genetic parameters for birth weight of Garole sheep, maintained at State Livestock Farm, Kalyani, Nadia, West Bengal. Birth records over a period of 7 years (2008–2014) for 1128 lambs descended from 30 rams and 251 ewes were analyzed by restricted maximum likelihood fitting-an animal model including various combinations of maternal effects. Six different animal models were fitted for this trait. The best model was chosen after testing the improvement of the log-likelihood values. Direct heritability estimate for birth weight was inflated substantially when maternal effects were ignored. Depending on the models used, the direct heritability estimates for this trait ranged from 0.03 0.24. The maternal genetic effects contributed 6–16% of the total variance for birth weight under different models. Estimates of fraction of variance due to maternal permanent environmental effects (c²) for this trait accounted for 5–11% of the total phenotypic variance in this study. Resultssuggested that both direct and maternal additive effects were important for analyzing the birth weight of Garole sheep.