Phenotypic association between residual feed intake and carcass traits of young nelore bulls

The purpose of this study was to estimate the phenotypic associations between residual food intake (RFI) and carcass traits, evaluated by ultrasonography, of young Nellore bulls. Information about 53 young Nelore bulls, pure origin (PO), participants in the Individual Performance Test of Nelore Bulls, carried out at the Capim Branco experimental farm of the Federal University of Uberlândia (UFU) were used for this purpose. It was evaluated the characteristics of residual feed intake (RFI), rib eye area (REA), marbling (MAR) and fat thickness (FT). In order to estimate the Spearman and Pearson correlation coefficients, the SAS program was used. Regarding the influence of the RFI classes (low RFI, medium RFI and high RFI) on carcass traits, an out analysis of variance was carried out using the least squares method. It was verified that there was no phenotypic association between RFI and the characteristics of REA and MAR, but the relation between FT and the phenotypic association revealed a medium magnitude. However, when evaluating the RFI classes, it was observed that there were no significant differences of the RFI classes with the carcass traits (REA, FT and MAR). It is recommended that new studies are carried out to verify if the selection for RFI does not result in damages to the finishing of carcass in Nelore cattle.