The work was carried out at the Centro de Pesquisa de Pecuária dos Campos Sulbrasileiros - CPPSUL/EMBRAPA, Bagé, RS, Brazil, (field experiment) and at the Departamento de Zootecnia da Universidade Federal de Pelotas - UFPEL, Pelotas, RS, Brazil, (laboratorial fase) during 1994/95. Male lambs from Texel, Romney Marsh, Corriedale, Polwarth and Merino breeds (10 lambs per breed), born and raised on native pasture (mainly of Paspalum notatum Flügge and Axonopus affinis Chase), were weaned at 10 weeks of age, after what were fed with 200g/lamb/day of a concentrate containing 17% of crude protein and 75% of dry matter basis. Carcass weight and fat content, as well as carcass regional composition (weight of its main pieces) and leg and shoulder tissue composition (% of bone, muscle and fat), were examined. The results showed that, with exception of rib weight and shoulder fat content, breed differences were significant (P<0.05). Texel and Romney lambs had heavier carcass than the other breeds (P<0.05), which showed similar weights (P>0.05). Merino lambs had higher % of shoulder and lower % of leg (P<0.05) than Texel lambs. Both were similar among other breeds. Texel lambs had lower % of neck than Merino lambs. There was no breed difference (P>0.05) for % of rib. Carcasses from Romney, Corriedale and Merino lambs presented lower fat content scores. Both the Texel and Polwarth breeds had lower % of bone in the leg, however, the former was greater in muscle percentage with lower fat content. Marked breed differences were found in the shoulder tissue composition. Texel lambs were lower in °/o of bone and higher in % of muscle (P<0.05). The other genotypes were similar (P> 0.0 5) for these components. There were no differences (P>0.05) regarding fat content in the shoulder.
lambs; carcass; regional composition; tissue composition; genotypes
