Peso de abate de machos não-castrados para produção do bovino jovem. 2. Peso, Idade e caracteristicas da carcaça

Abstract

To obtain slaughter weight and age and the carcass characteristics of young bulls, a feedlot study was conducted at Embrapa Pecuária Sudeste. A total of 215 animals from Embrapa and private farms, 3/8 and 1/2 Blonde d'Aquitaine x Nellore; 1/2 Canchim x Nellore; 1/2 Limousin x Nellore; 1/2 Piedmontese x Nellore; Canchim (CA) and Nellore (NE), were used in 1994, 1995 and 1997. The slaughter weights (TRAT) of 400 (I); 440 (II) and 480 kg (III), except for NE cattle (380, 410 and 440 kg), were tested. All animals received, ad libitum, a diet based on 50% whole plant corn silage and 50% concentrate, on a dry matter basis. The live weight of the animals were obtained after fasting of 16 hours. The animals were slaughtered at a commercial packing plant. The data were submitted to the analysis of variance and the means were compared by SNK tests. The straightbred Canchim and all crossbred animals were slaughtered at 231, 252 and 273 kg of hot carcass weight with an average age of 15.4; 16.1 and 16.8 months, for TRAT I, II and III, respectively; while straightbred Nellore were slaughtered at 211.5; 219 and 228 kg hot carcass weight with an average age of 16.4; 17.2 and 17.5 months, for TRAT I, II and III, respectively. The estimated means of days on feedlot, yield of carcass, rib eye area and backfat thickness were: 70.9; 95.1 and 114.7 days; 57.2; 57.7 and 58.3%; 31.4; 30.9 and 30.2 cm 2/100 kg carcass weight; 2.5; 3.1 and 3.6 mm, for TRAT I, II and III, respectively. The percentage of saleable meat from the hindquarter gunbit cut was similar for all three slaughter weights; while a reduction of the percentage of bones was compensated for by an increase in the percentage of trimmed excess fat with an increase of slaughter weight. There were significant interactions between genetic group and TRAT for estimated slaughter weights, percentage of hindquarter, hindquarter gunbit and forequarter cuts and the rib eye area.