Evaluation of growth of tissues and organs of crossbreed Holstein-Gyr steers during compensatory growth. 1. Carcass

[摘要] - The research aimed to analyze the effects of feed restriction prior to confinement on growth and chemical composition of the carcass and carcass components in cattle. Twenty-four Holstein-Gyr crossbred steers, with 19,3 ± 5,1 months of age and 202,1 ± 49,1 kg LW, at the beginning of the trial were used. Fifteen animals were confined after a 104-day period of forage restriction, in which it was intended to keep body weight unchanged (compensatory gain group), while nine of them had free access to pasture (continuous gain group). At beginning of the experiment and at days 28 and 112 of confinement, three animals of each group were slaughtered, and at days 56 and 84, three animals of compensatory gain group were slaughtered. During confinement, the animals from the compensatory gain group and continuous gain group were fed ad libitum; composed by corn silage and 26% of concentrate, as dry matter basis. The relative growth rates were evaluated through allometric equations. The rates of protein, fat and energy deposition in the carcass did not differ between treatments, in relation to empty-body weight gain. The protein deposition, in relation to empty body gain, was greater in compensatory growth group than in the continuous gain group. The compensatory weight gain cause a reduction in the protein deposition rate in carcass adipose tissue and an increase in the fat deposition rate in the bones of the carcass.

[学科分类] 兽医学

[关键词] allometric equations;carcas;cattle;growth   IntroduçãoNa pecuária de corte;busca-se aumentar a deposição de proteína no tecido muscular esquelético;mantendo o conteúdo de gordura dos animais dentro do mínimo necessário;visando um produto de melhor qualidade para o consumidor e;ao mesmo tempo;melhorar a eficiência econômica para o produtor