Body composition in relation to slaughter weight and gender in suckling lambs

Body composition was evaluated in 49 males and females suckling lambs of the Manchego breed slaughtered at 10, 12 and 14 kg. Lambs slaughtered at 14 kg had a greater proportion of loin-rib than those slaughtered at 10 kg. Male lambs exhibited a larger forequarter (neck, anterior rib and shoulder) while females had larger loin-rib. Slaughter weight affected the distribution of fat, and proportion of fat in loin-rib increased with slaughter weight. Males at 10 kg had more muscle in shoulder and neck than females. Significant slaughter weight × gender interaction was observed for total fat proportion in leg, loin-rib, anterior rib and flank. These proportions increased with slaughter weight in male lambs while in female lambs remained constant. The carcass composition of the suckling lamb showed significant correlations with muscle, fat and bone of the individual cuts, mainly leg and loin-rib. As expected, the proportion of muscle in the carcass was highly correlated with muscle in loin-rib, leg and shoulder. In conclusion, carcass composition may be predicted from the composition of leg and loin-rib.