Estimation of direct genetic and maternal effects for weaning traits in Egyptian buffalo [electronic resource].

Includes references.

Genetic parameters were estimated using REML in a multiple-trait animal model including direct genetic and maternal effects for birth and weaning weights and pre¬ weaning daily weight gain in 5519 Egyptian buffalo calves. Fixed effects considered were year-season of birth, sex of the calf and parity number of the dam for all traits plus weaning season and the linear covariate of age at weaning for the latter two traits, while direct additive and maternal additive-effects were random for all traits. All fixed effects contributed significantly (p < 0.001) to variation in all traits. Average birth and weaning weights and pre-weaning daily weight gain were 34.12. 86.95 and 0.55 kg, respectively. Direct heritability estimates were 0.07. 0.27 and 0.27 for the three traits respectively. The corresponding maternal heritability was 0.18, 0.08 and 0.01, respectively. Direct genetic correlations between these traits varied from low and negative (-0.11) between birth weight and daily gain to extremely high and positive (0.95) between weaning weight and pre-weaning daily gain. Direct heritability for weaning_ weight-and pre-weaning daily gain and the genetic correlation between them may indicate the possibility to improve both traits through genetic selection for buffaloes in Egypt.

Summary in Arabic.

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