Genetic parameters for mature weight and growth traits in Nelore cattle

Abstract

The animal breeding programs of beef cattle in Brazil have focused on selection for weight traits due to the fact that they are measures easily obtained. Within this context, it was analyzed data of 74,547 animals to evaluate the mature weight (MW) and the mature weight with repeated measurements (MWr) in Nellore animals. Heritability coefficients were estimated for mature weight and for other growth traits as post-weaning weight (PW), conformation (CONF), precocity (PREC), musculature (MUSC) and hip height (HH). The genetic correlation between those traits was also estimated. The (co)variances components were estimated by the Restricted Maximum Likelihood Multiple Trait Derivative Free method (MTDFREML), using the complete animal model. The estimates of heritability coefficients were 0.43 for MW and 0.41 for MWr; 0.38 for PW, 0.23 for CONF, 0.19 for PREC, 0.22 for MUSC and 0.35 for HH. The genetic correlation coefficients ranged from 0.37 to 0.70. The heritability coefficients suggest that mature weight may respond to selection and be used to monitor the size of females from the Nellore breed. The genetic correlation coefficients between mature weight and other growth traits were high and positive, indicating that selection for mature weight influences the performance of the other studied traits.