Resumen
- The objective of this study was to estimate the heritabilities and genetic tendencies for weights at birth (PN), weaning adjusted to 240 days (PDA) and at 16 months (P16) in Romosinuano Creole cattle. Information from the years 1960 to 2011 of the IC Turipaná database was used, using unicaracteristic models that included the fixed effects of a contemporary group (sex-season-year), genetic random effects, direct additive of the animal, genetic maternal additives (only for PN and PDA), permanent maternal environment (only for PN and PDA) and residual. The components of variance and genetic parameters were estimated through Restricted Maximum Likelihood, through the AIREML program. The direct heritability for PN was 0.19 ± 0.04, for PDA of 0.13 ± 0.04 and for P16 of 0.21 ± 0.05. The maternal heritabilities for PN and PD were 0.003 ± 0.02 and 0.08 ± 0.03, respectively. The correlations between direct and maternal genetic effects for PN and PD were negative (-0.49 ± 0.68 and -0.13 ± 0.27). The genetic tendencies for direct genetic effects for the characteristics under study were all positive (P <0.01), although they suggest little genetic progress in the population.