The objective of this work was to evaluate average daily gain (ADG) and carcasstraits in Nellore and Red Norte steers, finished in feedlots and to evaluateperformance predictions by using the systems BR-CORTE, CNCPS 5.0 and NRC (2000).It was used 41 steers: 19 Nelore animals with initial body weight of 361 ±31 kg and 22 Red Norte animals with initial body weight of 367 ± 30 kg.Adaptation period lasted 28 days. Animal performance evaluation was composedof three 28 day period, totaling 84 days. At the end of each period, animalswere weighed after a 16-hour feeding fast. Average gain weight of Red Nortesteers was greater than Nellore breed animals (1.43 vs. 1.81 kg/day,respectively). Red Norte animals also presented greater loin eye area (75.41cm2 vs. 68.67 cm2). It was not observed any differenceson subcutaneous fat thickness and on rump fat among the genetic groups. Noneof the nutritional requirement system evaluated were efficient in predictinganimal performance. For Nellore breed, daily average gain observed was 1.53kg/day,with values of 1.53, 1.70 and 1.82 kg/day predicted by NRC, CNCPS and BR-CORTEsystems. Although average values and predicted by NRC were similar, accordingto the regression equation, intercept and inclination were different from zeroand one. For Red Norte breed, performance observed was 1.88 kg/day with valuesof 1.50, 1.66 and 1.72 predicted by the systems NRC, CNCPS and BR-CORTE, probablybecause database of those systems is based mainly on results obtained from Angusbovines.
