Estimation of genetic parameters for preweaning and postweaning growth traits in the Gudali beef cattle using multiple trait derivative free restricted maximum likelihood

Abstract

Records on pedigree information and growth traits of Gudali beef calves were obtained from the Institute of Agricultural Research for Development, Cameroon. Data were edited to have complete information on calf, sire and dam identity, sex, dates and season of birth, herd and weights at birth (BWT), 6 months (6 MWT), weaning (WWT), 12 months (12 MWT), yearling (YWT), 18 months (18 MWT), 24 months (24 MWT) and 36 months (36 MWT). Genetic parameters were estimated using multiple trait derivative free restricted maximum likelihood (MTDFRML) program. The estimated direct (h²_a) and maternal (h2m) heritabilities for BWT, 6 MWT, WWT, YWT, 18 MWT, 24 MWT and 36 MWT obtained were 0.39, 0.10, 0.25, 0.21, 0.18, 0.25, 0.18 and 0.05, 0.07, 0.11, 0.10, 0.05, 0.09, 0.07, respectively. Estimates of maternal genetic variance and corresponding heritabilities (h²_m) were lower than estimates for direct additive variance and heritability (h²_a). The genetic correlation between direct and maternal influence were negative. The across-trait direct and maternal genetic correlation estimates were medium to high with the exception of BWT and 18 MWT; BWT and 36 MWT, had negative values. The positive values reported for the additive and maternal correlations between the growth parameters indicate that selection for one trait resulted in genetic improvement in the other. The moderate values of heritabilities indicate that selection for growth traits was effective.

Key words: Covariance, heritability, genetic correlation, growth traits.