CONSUMO ALIMENTAR RESIDUAL E CARACTERÍSTICAS REPRODUTIVAS EM FÊMEAS DA RAÇA NELORE

Abstract

The hypothesis evaluated in the present study is that Nellore females considered more efficient for Residual Food Consumption (RFI) adjusted for fat have lower body energy reserves and this consequently affects their reconception after the first parturition as early primiparous. Still, the objective was to evaluate the relationship between reproductive traits with growth traits and feed efficiency. The phenotypic and genetic correlations between RFI adjusted for fat and fat thickness measured on the last test day (EG) were low and not significant. Regarding the RFI correlations with the reproductive characteristics Days of gestation for the first pregnancy (DGP), Days of gestation for the second pregnancy (DGS), Days for the first pregnancy (DPP) and Days for the Second Pregnancy (DPS), Probability of Pregnancy in second conception (PRE2) and probability of second birth (P2), were low and not significant in the phenotypic and bayesian genetic analyses. In the logistic regression analysis with the phenotypic data, there was no significant effect for any characteristic to determine the PRE2 and P2. The evaluated heritability values were low for the traits RFI, CA, IPC, DGP, DGS, DPP, DPS, PRE2 and P2. Moderate values were found for ADGtest, ADGlife, DMI, Metabolic Weight, final AOL and final EG. The results suggest that the selection of more efficient animals (lower RFI) does not affect early primiparous reconception, but it should be noted that it will be selecting animals with lower DMI and, consequently, lower ADG. These results may be influenced by the intensity of the environmental challenge imposed on these females when they are primiparous. Thus, it is interesting to obtain data like this one in other creation environments.