STEERS CARCASS CHARACTERISTICS WITH DIFFERENT GENETIC PREDOMINANCE FED WITH DIETS CONTAINING SUBSTITUTION LEVELS OF GRAIN CORN BY MILLET GRAIN

Abstract Text: This study aimed to evaluate the crossbred steers carcass and meat characteristics with European or Zebu genotypic predominance. Considered that commercial animals were used, these animals were divided by genotypic predominance, by visual evaluation. Feedlot finished with high diets concentrated percentage (80%), containing different levels of grounded millet grain as replacement for grounded corn grain (0, 33, 66 and 100%). Forty-five steers with European predominance and forty-four steers with Zebu predominance, with initial average weight of 317.8 and 320.7 kg, respectively, and average age of 21 month, were allocated in 16 collective pens. In the total, 89 animals were used from the beginning to the end of the feedlot, but for the slaughter evaluation, 06 steers were used from each treatment for carcass evaluation. The animals from each genetic predominance were randomly chosen within of each level of corn substitution by millet grain. The experimental design was completely randomized with factorial arrangement 04 (diets) x 02 (genetic groups – predominance) x 06 (animals). The corn grain replacement by millet grain did not influence significantly slaughter weight (480.4 kg) (P>0.05), hot carcass weight (259.5 kg) (P>0.05), carcass yield (54.1%) (P>0.05), subcutaneous fat thickness (3.95 mm) (P>0.05). Steers predominantly European genotype showed significant higher values for slaughter weight (507.6 vs. 453.3 kg) (P<0.001), hot carcass weight (269.6 vs. 249.3 kg (P<0.001) and Longissimus dorsiarea (65.34 vs 56.83 cm2) (P<0.001), however they were lower in carcass yield (53.2 vs. 55.0%) (P<0.001). Millet grain can be used in corn grain substitution for finishing steers since it does not change carcass traits of economic interest. Steers with European predominance are heavier at slaughter, presenting heavier and better carcass conformation.

Keywords: Carcass weight, subcutaneous fat, zebu.