Carcass characteristics and yields of Nellore bulls compared with 1/2 and 1/4 blood Marchigiana-Nellore bulls

Abstract

Four groups totaling 36 young bulls were placed in a dry lot and individually fed a ration of 66% TDN. There were two groups of ten Nellore bulls (Nellore I and Nellore II) and two groups, one of ten one-quarter Marchigiana-Nellore and one of six one-half Marchigiana-Nellore bulls (crossbred I and crossbred II, respectively). Nellore I bulls averaged 689 days of age and the other three groups averaged 613 days of age at the start of the trial. All animals were randomly assigned to three slaughter time groups (1, 2 and 3) and were fed for 119, 152 or 175 days. The crossbred II bulls had heavier (P< .05) live weights (513.5 kg) at slaughter than the Nellore I, Nellore II and crossbred I groups (476.0, 464.5 and 479.0 kg respectively). Consequently, crossbred II bulls showed heavier (P< .05) hot and chilled carcass weights than the other groups. Also the crossbred II bulls had less (P< .05) 12th rib fat cover (3.5 mm) with Nellore II bulls having lhe thicker 12th rib fat cover (6.1 mm) and Nellore I and crossbred I groups being intermediate (4.7 and 4.6 mm respectively). Loin eye area was larger (P < .05) for crossbred II (79.65 cm²) than for Nellore I, Nellore II and crossbred I groups (70.39, 68.57 and 65.93 cm²respectively). A marked advantage was shown for the crossbred II group from the standpoint of producing greater quantities of lean meat without excess waste fat. This group had higher (P< .05) proportion of edible portion from the special hindquarter (33.65%), higher (P< .05) proportion of total edible portion (76.30%) and lesser amounts of trimmable fat (6.96%).