Efeitos de raça e heterose na composição física da carcaça e na qualidade da carne de novilhos da primeira geração de cruzamento entre Charolês e Nelore

Abstract

Carcass characteristics of 463 steers, born during 1984 to 1996, from two breeding systems: straightbreds (S) and F1 crossbreds were studied. The S breeding system included the 188 Charolais (C) and 125 Nellore (N) steers and the F1 included 72 1/2 C 1/2 N and 78 1/2 N 1/2 C steers. F1 steers were superior than the purebreds in carcass fat percentage, muscle/bone relation, muscle + fat/bone relation and marbling score, being heterosis levels of 3.33, 2.92, 3.67, and 23.64%, respectively. Comparing the two breeding systems, it was observed that the straightbred animals were superior than F1 in carcass muscle percentage, being the heterosis level of -3.08%. Within the S breeding system the Charolais showed higher carcass muscle percentage (68.4 vs. 64.4%), muscle/bone relation (3.57 vs. 3.29), muscle + fat/bone relation (4.43 vs. 4.30), texture (3.80 vs. 3.58 points), tenderness (6.81 vs. 4.89 points), flavor (5.82 vs. 5.41 points) and juiciness (6.28 vs. 5.66 points), while the Nellore steers showed higher values for carcass fat percentage (19.6 vs. 16.3%), carcass bone percentage (19.7 vs. 19.2%), Shear force (9.29 vs. 6.01 kg), thawing losses (8.54 vs. 6.79%) and cooking losses (30.72 vs. 28.12%). The crossbreeding between Charolais and Nellore resulted in positive heterosis and additive genetic complementarily for carcass and meat characteristics important to the slaughterhouses and to the consumers.