S. R. de Medeiros

Differences in residual feed intake are largely explained by changes in body composition

Genetic selection of efficient animals can result in lower costs, reduced environmental impact and increased profitability. The associations between feed efficiency selection and performance are known, however the possible impacts on body composition of Nellore are still unknown. Residual feed intake (RFI), defined as the difference between observed and predicted intake (predicted from metabolic body weight and daily gain) (Koch et al., 1963), has been proposed as an index for genetic selection, however, differences in body composition have been pointed out as a limiting factor in the use of RFI for cattle selection (Herd and Pitchford, 2011). The objective of this work was to examine the relationship between RFI and body composition in Nellore steers.