Genetic parameter estimates of pre-weaning weight of Horro (Zebu) and their crosses with Holstein Friesian and Jersey cattle breeds in Ethiopia

0.53 ± 0.097 for WW and 0.29 ± 0.08 for DG, respectively. Direct maternal heritability estimates were BW (0.12 ± 0.10), WW (0.21 ± 0.08) and DG (0.21 ± 0.07), respectively. The ratio of permanent maternal environment was 0.17 to 0.18 for BW, 0.018 to 0.03 for WW, 0.016 to 0.023 for DG, respectively. Directmaternal genetic correlations were: -0.76, -0.71 and -0.89, for BW, WW and DG, respectively. High direct heritability estimates observed for birth weight indicated that in Horro and their crosses faster genetic improvement through selection is possible for this trait. However, the results suggested that both the direct and maternal effect should be taken into account simultaneously during selection because of the high negative direct and maternal genetic correlation. From this study, it was suggested that estimation of genetic parameters for pre-weaning growth traits should be carried out separately for Horro and their crosses.