Meat production in sheep of five genotypes. 5. Quality and carcass weight estimation through liveweight

摘要

The work was carried out at the Centro de Pesquisa de Pecuária dos Campos Sulbrasileiros (CPPSUL) of EMBRAPA, Bagé, RS, Brazil, with the participation of the FAEM/UFPel, Departamento de Zootecnia, Pelotas, RS, Brazil, during 1994/96. It was used a total of 117 male lambs of the Texel (n =26), Romney Marsh (n =24), Corriedale (n =26), Polwarth (n =23) and Merino (n=18) breeds, born and raised up to weaning (10 weeks) on native pasture (mainly composed by Paspalum notatum Flügge e Axonopus affinis Chase). After weaning, besides the native pasture, all lambs were fed with 200 g/lamb/day of a concentrate containing 17% of crude protein and 75% of dry matter basis, until slaughtering at 7,5 months of age. The between breed relationship of liveweight with carcass weight and some indicators of carcass quality were examined. The results showed that the regression coefficients of carcass weight on slaughtering weight were similar, however, there were differences on the height of the regression lines, derived from values of both Texel and Romney lambs. By increasing liveweight: a) there was no effect on carcass fat content; but carcass cover fat varied in the Romney breed, b) carcass conformation was not affect in Corriedale and Romney Marsh lambs and c) carcass compacity was affected in Polwarth, Corriedale, Romney Marsh and Texel lambs.