Ciência Rural (Aug 2000)
Crescimento de cordeiros abatidos com diferentes pesos: osso, músculo e gordura da carcaça e de seus cortes Growth of lambs slaughtered at different weights: bone, muscle and fat of the carcass and its cuts
Abstract
O trabalho foi realizado no Setor de Ovinocultura do Departamento de Zootecnia da Universidade Federal de Santa Maria, objetivando determinar as quantidades de osso, músculo e gordura da carcaça e o crescimento de osso e músculo da carcaça e dos diferentes cortes da mesma. Foram utilizados 22 cordeiros machos inteiros, filhos de carneiros Texel e ovelhas cruza (Texel x Ideal). Desses, quatro/oram abatidos no início do experimento (24 horas após o nascimento), e os restantes, ao desmame (45 dias de idade) e aos 28 e 33kg. Os cordeiros foram confinados em baias individuais, com suas respectivas mães, até o desmame (45 dias de idade). A determinação do crescimento dos tecidos da carcaça e de seus cortes (quarto, paleta, costela, espinhaço e pescoço) foi realizada através de equações alométricas, utilizando-se o logaritmo do peso de osso ou músculo, em função do logaritmo do peso de corpo vazio (PCV) ou peso de carcaça fria (PCF). As quantidades de osso e músculo aumentaram (P0,05) com a elevação do peso de carcaça fria. A proporção de gordura aumentou do nascimento ao desmame (PThis experiment was developed at the Ovine Section of Animal Science Department, at Federal University of Santa Maria, Brazil- The purpose of this experiment was to determine the quantity of bone, muscle and fat of the carcass, and the growth ofbone and muscle of the carcass, and of the carcass cuts. Twenty-two intact mate lambs, sired by Texel males, from crossbreed Texel -Ideal dams were used. Four lambs were siaughtered at the beginning of the experiment (24 hours after birth) and groups of six lambs were siaughtered at weaning and when reaching 28 and 33kg. The lambs were kept in individual stalls together with their respective mothers until weaning (45 days of age). To study the growth of the carcass tissues and carcass cuts (hindquarter, shoulder, rib, backbone, neck), regression equations of the log of weight of each tissue, as a function of the log of empty body weight (EBW) or cold carcass weight (CCW) were fitted. The quantities of bone and muscle -increased (P0.05) with the higher of the CCW, the proportion of fat increased from birth to weaning (P<0.05) and decreased after weaning (P<0.05). In relation to EBW and CCW, bones were early maturing (b=0.729188 and b=0.673340), followed by muscular tissue (b=1.075728 and b=1.001403). Among carcass cuts rib bone and muscle were later maturing than in other cuts.
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