Efeito do Grupo Genético e da Heterose na Composição Física e nas Características Qualitativas da Carcaça e da Carne de Vacas de Descarte Terminadas em Confinamento

Carcass physical composition and meat qualitative characteristics of cull cows from two breeding systems, straightbreds (Charolais and Nellore) and crossbreds F1 1/2 Charolais-Nellore and 1/2 Nellore-Charolais, were evaluated. The cows were feedlot finished during 80 days and fed with 65% roughage (sorghum silage) and 35% concentrate, in dry matter basis. Charolais cows showed carcass with higher muscle (65.2 vs 58.8%) and bone (15.36 vs 13.7%) percentages, higher muscle (166.5 vs 139.61 kg) and bone (38.84 vs 32.34 kg) production than Nellore cows. Meat from Charolais cows also exhibited better color (3.75 vs 3.14), tenderness (6.22 vs 5.34) and juiciness (6.16 vs 5.56). Nellore cows showed higher fat percentage (27.95 vs 19.85%), total fat production (66.7 vs 51.2 kg) and higher meat thawing losses (6.15 vs 4.18%). Crossbreds F1 females were superior to the straightbreds for fat percentage (26.74 vs 23.9%), total fat production (72.79 vs 58.95 kg), however, showed lower muscle percentage in the carcass (59.59 vs 62.02%), being the heterosis values 11.88, 23.48 and ¾3.92%, respectively. Meat qualitative characteristics were not affected by the breeding system.