In the present work we aimed to compare intake, performance, feed efficiency and carcass traits of cattle from three genetic groups (GG) fed two concentrate levels in the diet. Forty-eight steers (16 Nellore, 16 Nellore-Red Angus and 16 Nellore-Simmental) were used. Twelve steers were slaughtered at the beginning of experiment as a reference group and for the remaining 36 animals, the concentrate mixture of the ration was offered as 1 and 2% of body weight basis in a 3 × 2 factorial arrangement in a completely randomized design, with six repetitions. The value of significance defined was 0.05. Isoprotein diets were composed of corn silage and concentrate. The trial was comprised of 3 periods of 28 days each and all animals slaughtered at the end. The dry matter and nutrients intake was higher in diets with high concentrate level of steers, except for neutral detergent fiber. The dry matter intake of crossbred steers was higher than that of Nelore, however Nellore-Angus presented greater intake as compared with Nellore-Simmental. No differences were observed for animal performance among concentrate levels. Conversely carcass and empty body weight gain were higher as 2% of body weight concentrate was offered. The crossbreds performance was higher than that of Nelore, although no differences were verified among crossbreds. No differences were found in the bionutritional index between the two concentrate levels, in feed efficiency to both carcass and empty body weight gain. Animals consuming concentrate mixtures at the level of 2% of body weight presents greater intake and performance than those that receive level of 1% of body weight basis, but with no differences in feed efficiency. The Nelore-Simental is more efficient than the Nelore-Angus, but both crossbreds are more efficient than Nelore.
Angus; bionutritional index; intake; Nellore; performance; Simmental
