the impact of maternal effects on genetic parameters of performance traits in a commercial broiler dam line

in this study, the effect of maternal additive genetic and environment on body weight at 6 weeks (bwt6w), breast width (hbrs), carcass weight (carcwt), breast weight (brswt), blood hematocrit value (hem), residual feed intake (rfi), daily feed intake (dfi) and average daily gain (adg) were investigated in a commercial broiler dam line. with and without maternal effects, six different animal models were taken into account, and the most appropriate model chosen as based on likelihood ratio test. data were analysed through animal model, dmu software. as for bwt6w, hbrs, rfi, dfi and adg, direct and maternal additive genetic effects with direct-maternal additive genetic covariance and maternal environmental effects (model 8) were significant (p0.05).the results indicated that ignoring maternal effects in the analysis tended to overestimate direct additive genetic variances as well as their corresponding heritabilities for all the traits.