The objective of this study was to evaluate the internal organs and digestive tract of two categories, steers and cull cows, from two genetic groups: 5/8 Charolais (Ch) 3/8 Nellore (Ne) and 5/8Ne 3/8Ch, finished in feedlot. We used 12 steers and 12 cull cows, being the categories compounded for six 5/8Ch 3/8Ne animals and six animals 5/8Ne 3/8Ch. The average age of animals at the end of the experimental period was 23 and 68 months for steers and cull cows, respectively. The animals were feedlot-finished until reaching finishing degree for slaughter. The experimental diet had a roughage:concentrate ratio of 40:60 (dry matter basis). The experimental design was completely randomized in a 2 x 2 (two categories and two genetic groups) factorial scheme. Data were submitted to analysis of variance by proc GLM, being the means classified by test "F" and the parameters with significant effects for interaction between genetic group and category compared by "test t", with 5% significance level. Slaughter weight (SW) (509.67 versus 414.50kg) and empty body weight (EBW) (433.01 versus 355.27kg, respectively) were higher for cows in relation to steers. The cull cows showed higher absolute weight for heart (1.62 versus 1.40 kg), liver (7.07 versus 5.95 kg) and for total internal organs, digestive tract and blood. When the components were adjusted for percentage of EBW the steers were superiors on lungs (1.08 versus 0.95%), spleen (0.29 versus 0.22%) intestines (2.04 versus 1.70%) and total internal organs weight (3.91 versus 3.60%). As genetic groups, 5/8Ch 3/8Ne animals showed higher absolute weight for digestive tract. The carcass dressing percentage and non-carcass components, in absolute weight, showed correlation. Cull cows showed higher weight for internal organs and digestive tract than steers slaughtered at 24 months, while cattle for genetic group 5/8Ch 3/8Ne showed higher weight for compartments and total of digestive tract in relation to 5/8Ne 3/8Ch bovines.
abomasum; animal category; carcass dressing percentage; empty body weight; liver