Muscle weight distribution in lambs: a comparison of entire male and female

Abstract

ABSTRACTThe carcasses of 15 ram and 15 ewe lambs of the Dorset Down breed, weight range 12 to 23 kg, were separated into individual muscles, bones and fat depots.At the same carcass weight (16-8 kg) the ram lambs contained 41 g more muscle per kg, but there were few important differences between sexes in individual muscle weights; 65 of the 72 muscles differed in weight by less than 10 g.The distribution of total muscle weight between eight anatomical groupings differed significantly between the sexes; ewes had proportionately more muscle in the proximal pelvic limb (8 g/kg) and less in the neck (7 g/kg) and distal thoracic limb (1 g/kg). Despite these small differences in muscle-weight distribution in higher-valued joints in favour of the ewe lambs, each of their joints contained less muscle than those of ram lambs.In these lambs, reared under commercial conditions in the United Kingdom, there were no signs of gross morphological differences which could result in their disqualification for the Variable Premium of the European Economic Community Sheepmeat Regime. In particular the m. splenius cervicus was a very small proportion of total muscle in both sexes (1·5 and 2·5 g/kg for ewe and ram respectively).