Carcass physical composition and physic-chemical characteristics of meat from Nellore cattle

Abstract

Assessment of carcass physical composition and physicochemical characteristics of meat from Nellore males distributed randomly into three treatments: males castrated at 13 months of age at puberty (n=26); castrated at 18 months of age, 15 days before confinement (n=26); and young bulls (n=25). For the evaluation of meat chemical characteristics, we used samples of 12 animals taken at random from each treatment. The experimental design was completely randomized. Animals were slaughtered at 22 months of age after 100 days of confinement. The carcasses of young bulls showed higher contents of muscle (66.46 %) and bone (16.03 %), and lower fat content (17.66 %), in relation to that of steers castrated at 13 (62.83,15.28, and 22.11 %, respectively) or 18 months (63.99, 15.29, and 21.53%, respectively), which did not differ amongst themselves. The meat of young bulls was darker (3.07 points) than the meat from those castrated at 13 months of age (3.43 points), while the meat from those castrated at 18 months displayed an intermediate color (3.29 points), not differing from the others. Young bulls yielded meat with lower content of intramuscular fat (3.18 points) and lipids (3.81%) in relation to those castrated at 13 (4.58 points and 6.77%, respectively) or 18 months (4.52 points and 5.66%, respectively). Protein content was higher (P<.05) in meat from steers castrated at 13 months in relation to young bulls. The shear strength of the muscle fibers was not altered (P> 0.05) by the age of castration, with young bulls having lower values in relation to the castrated males. Castration of Nellore young bulls in early puberty increases the edible portion of the carcass due to the higher body fat deposit. Key words: Cattle. Sexual condition. Age at castration. Lipids. ResumoAvaliação da composição física da carcaça e das características físico-químicas da carne de tourinhos e novilhos Nelore distribuidos aleatoriamente em três tratamentos: machos castrados aos 13 meses de idade, no início da puberdade (n=26); castrados aos 18 meses, 15 dias antes do início do confinamento (n=26); e não castrados (n=25). O delineamento experimental utilizado foi o inteiramente casualizado com 12 repetições. Os animais foram abatidos com 22 meses de idade após 100 dias de confinamento. Os tourinhos apresentaram maior conteúdo de músculo (66,46%) e osso (16,03%), e menor conteúdo de gordura (17,66%) na carcaça em relação aos castrados com 13 (62,83; 15,28 e 22,11%, respectivamente) ou 18 meses (63,99; 15,30 e 20,96%, respectivamente), que não diferiram entre si. A carne de tourinhos foi mais escura (3,07 pontos) em relação aos castrados aos 13 meses de idade (3,43 pontos), enquanto a carne dos castrados aos 18 meses apresentou coloração intermediária (3,29 pontos), não diferindo dos demais. Tourinhos produziram carne com menor conteúdo de gordura intramuscular (3,18 pontos) e de lipídios (3,81%) em relação aos castrados com 13 meses (4,58 pontos e 6,77%, respectivamente) ou 18 meses de idade (4,52 pontos e 5,66%, respectivamente). O ...