The objective of this trial was to evaluate the carcass physical composition and meat qualitative characteristics of males of two categories, steers (slaughtered at 22.8 months old) and young steers (slaughtered at 15.2 months old), from two genetic groups, 5/8 Charolais (CH) 3/8 Nellore (NE) and 5/8NE 3/8CH, and to evaluate the relationship among the variables studied. The animals were fedlot finished until reaching 430 kg. The diet, roughage:concentrate ratio of 60:40 (dry matter basis), contained 10.25% crude protein and 3.18 Mcal of digestible energy/kg of dry matter. The experiment was analyzed as a complete randomized design with six replicates, according to a 2 x 2 (two categories x two genetic groups) factorial scheme. Steers showed carcasses with higher percentage and total quantity of muscle (66.45% and 153.93 kg vs. 60.27% and 141.00 kg), higher muscle:fat ratio (3.64 vs. 2.45), carcasses with lower percentage and total quantity of fat (18.59% and 43.59 kg vs. 24.78% and 58.07 kg), meat with less marbling (6.25 vs. 8.42 points), less juiciness (6.83 vs. 7.34 points) and lipid content (1.01 vs. 1.76%) than young steers. Steers showed equal meat color (4.42 points) and similar meat tenderness, evaluated by the test panel (6.53 and 6.92 points) and shear force (3.84 and 4.22 kgf/cm³) in relation to young steers. The 5/8NE 3/8CH animals showed carcasses with higher fat percentage (22.43 vs. 20.95). Meat quality characteristics were not influenced by genetic group. Meat tenderness was positively correlated with percentual (r = 0.27) and total (r = 0.31) carcass fat, and with marbling score (r = 0.28). Meat juiciness showed positive correlation with percentual (r = 0.45) and total (r = 0.47) carcass fat. The two last ones were negatively associated with thawing loss (r = - 0.23 and -0.31, respectively).
Canchim; compensatory gain; lipid; marbling; muscle percentage; tenderness
