الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
A total of 1173 records of Egyptian buffalo calves kept at Mehalet Mousa Farm, belonging to Animal Production Research Institute, Ministry of Agriculture, Dokki, Cairo, Egypt during the period from 2004 to 2017 were used to estimate variances of direct and maternal genetic effects for birth weight (BW) and weaning weight (WW). Two animal models are used. Model 1 (full model) includes month and year of birth, sex and dams parity as main fixed effects and direct genetic, maternal genetic, covariance between direct and maternal genetic and residual as random effects. Model 2 is similar to model 1 while additive maternal genetic and covariance between direct and maternal effects were omitted from the analysis. Year of birth, sex and dams parity had highly significant effects on BW and WW, while month of birth had no significant effects on both traits studied. Bulls of the buffalo and dams within bulls had highly significant effects on BW and WW. Direct heritability estimates for BW were 0.30 and 0.33, for Model 1 and Model 2, respectively. Direct heritability estimates for WW are 0.34 and 0.39 for Model 1 and Model 2, respectively. Maternal heritability estimates are 0.10 and 0.03 for BW and WW, respectively. Phenotypic and genetic correlations among BW and WW are positive and highly significant. Predicted sire breeding values as estimated from multi trait animal model ranged from -3.10 to 3.15 kg for BW and from -12.03 to 21.21 kg for WW. These results indicate the important of maternal genetic effect on birth weight.