The Growth Performance and Carcass Composition of Ram and Ewe Lambs Fed on Pasture or in Confinement and Slaughtered at Similar Fatness

Abstract

. 1984. The growth performance and carcass composition of ram and ewe lambs fed on pasture or in confinement and slaughtered at similar fatness. Can. J. Anim. Sci. 64: 631_640.Forty-nine crossbred ram lambs and 62 crossbred ewe lambs were allotted at weaning (average weight 30.6 kg) to pasture (P) or concentrate (C) feeding. The number of lambs per treatment was as follows '. rams, 24 P fed and 25 C fed; ewes, 3 I P fed and 3l C fed. The lambs were slaughtered after 56, 72, 100 andl2l days on feed.Offal components were weighed, and the alimentary tract was emptied of digesta.One side ofeach carcass was broken into four cuts (leg, loin, rib, shoulder) which were further separated into fat, muscle and bone. C-fed lambs were 4.\Vo heavier live than P-fed lambs (P<0.05) and ram lambs were 9.0Voheavier live than ewe lambs (P<0.05) when evaluated at a constant depth of subcutaneous fat (4.5 mm).However, P-fed lambs required an extra 2l days (P<0.05) to reach the same fat depth as C-fed lambs. C-fed lambs had greater rib eye areas than P-fed lambs, but carcasses from all treatments had similar proportions of dissected muscle, bone and fat when evaluated at a constant proportion of subcutaneous fat. P-fed lambs had a greater proportion of their empty bodies as head and reticulo-rumen, and a lower proportion as liver and large intestine than C-fed lambs. Ram lambs had a greater proportion of their empty bodies as head, and a lower proportion as caul fat, mesenteric fat, omasum and small intestine than ewe lambs. Distribution of muscle and bone among each of the four meat cuts which were evaluated was similar for all carcasses. Sex and feeding system had only a minor effect on the distribution of the fat depots. In this study, lambs fed on pasture required 21 days longer on feed to reach the same external fatness as concentrate-fed lambs, but produced carcasses of similar composition at slightly lighter iiveweights (45.3

Características da carcaça de cordeiros alimentados com dietas contendo grãos de milho conservados em diferentes formas

“…As variáveis Cobertura de Gordura (CBG), Cor da Gordura (CG) foram semelhantes, com valores para coloração da gordura equivalentes aos apresentados por JONES et al (1984). Com relação aos valores constatados para cobertura de gordura, não houve diferenças (P>0,05) entre as dietas avaliadas.…”

“…Constatou-se que não houve efeito dos tratamentos sobre o parâmetro AOL, ressaltando-se que os valores obtidos são compatíveis com carcaças de alta qualidade de acordo com JONES et al (1984) e MACEDO (1998). Não houve efeito de tratamento sobre espessura de gordura; entretanto, constatouse que, à medida que o peso vivo aumenta, elevase a medida desta variável, ressaltando-se, porém, os excelentes níveis de tecido adiposo nestas carcaças (média de 2,11), estando de acordo com JONES et al (1984).…”

The effects of diet, slaughter weight and docking on growth, carcass composition and meat quality of fat-tailed Barbarine lambs. A review

“…The intake of energy exceeded the requirements for growth and maintenance, which shifted metabolism to fat production at younger ages (Dimsoski et al 1999). However, Jones et al (1984) reported no difference in carcass characteristics between concentrateand pasture-fed lambs, when adjusted for subcutaneous fat. They concluded that, within breed, weight was more important in determining body composition than growth rate or plane of nutrition.…”

Rendimento, composição tecidual e musculosidade da carcaça de cordeiros Santa Inês alimentados com diferentes níveis de feno de flor-de-seda na dieta

“…Segundo Purchas et al (1991), muitas vezes esta Tabela 4 -Médias e equações de regressão para os rendimentos de osso (RO), de músculo (RM), de gordura (RG) e de outros tecidos (ROT) da carcaça de cordeiros Santa Inês alimentados com dietas contendo níveis crescentes de feno de flor-de-seda Tabela 5 -Médias e equações de regressão para a musculosidade da carcaça determinada por meio da relação músculo:osso (M:O), do índice de musculosidade da perna (IMP) e da área de olho-do-lombo (AOL) de cordeiros Santa Inês alimentados com dietas contendo níveis crescentes de feno de flor-de-seda (Mello, 2000;Lira Filho, 2004 Segundo Müller (1980), a AOL, isoladamente, não tem correlação alta com a proporção de músculos da carcaça, mas, se avaliada em conjunto com outras características de carcaça, auxilia na avaliação do grau de rendimento de cortes desossados. Os animais dos tratamentos com 0 e 33% de FFS apresentaram, respectivamente, 11,83 e 11,99 cm 2 de AOL, compatíveis com carcaças de alta qualidade, segundo Jones et al (1984) e Macedo (2000.…”