The objective ofthis work was to evaluate performance, efficiency parameters and phenotypiccorrelations among measurements of energy efficiency of Nellore cattle selectedfor post weaning weight and classified according to residual feed intake, calculatedby the difference between observed and predicted intake, based on average metabolicbody weight and average daily gain. Thus, animals were classified within threegroups: high (> mean + 0.5 standard deviation, less efficient); medium (±0.5standard deviation of the mean); and low (< mean - 0.5 standard deviation,more efficient) residual feed intake. No differences were observed at initialand final body weights, average daily gain and dry matter intake among groups.Animals with low residual feed intake also had greater feed efficiency, feedconversion and partial efficiency of growth and did not differ from the otheranimals regarding to relative growth rate and Kleiber ratio. Residual feed intakewas significantly correlated to feed efficiency (-0.25), feed conversion (0.25),partial efficiency of growth (-0.37) and dry matter intake (0.16) but it didnot present significant correlation with body weight (0.04), average daily gain(-0.02), relative growth rate (-0.03) and Kleiber ratio (-0.05). Significantcorrelations were found between feed conversion and initial body weight (0.34)and average daily gain (-0.46). Partial efficiency of growth presented significantcorrelation with all other efficiency parameters analyzed. Residual feed intakehas high potential in productive efficiency, when compared to the other energyefficiency measurements, being independent of growth and size of the animals.
