Use of carcass weight to classify Manchego sucking lambs and its relation to carcass and meat quality

Abstract

Eighty-seven Manchego sucking lambs raised exclusively on maternal milk were slaughtered. The carcasses were weighed immediately after dressing and classified according to hot carcass weight (HCW): low HCW (<5.5 kg), medium HCW (5.5 to 6.5 kg) and high HCW (≥ 6.5 kg). The effects of this classification system on carcass and meat quality were studied. Carcass conformation improved as carcass weight increased; carcasses became more compact. Carcass fatness increased (P< 0.001) as carcasses became heavier. With regard to the joints, leg (P< 0.001) and shoulder (P< 0.05) proportions decreased as carcass weight increased, whereas loin-rib (P< 0.001) and flank (P< 0.001) proportions increased. The proportion of fat in the leg clearly increased in the heavier carcasses (P< 0.001), while that of bone decreased (P< 0.001) and that of muscle was not affected. pH at 24 h in them. longissimusdorsi andm. semitendinosusdecreased as carcass weight increased. The only meat colour parameter affected by carcass weight was the yellowness index; lighter-weight carcasses displayed lower index (P< 0.05). Cooking losses were unaffected as carcass weight increased, whereas with regard to tenderness, the shear force value tended to be higher in the low carcass weight group. No differences between carcass weight groups were found in the sensory analysis. Fatty acid composition did not show any significant effect due to carcass weight except in stearic fatty acid (C18:0); C18:0 proportion decreased (P< 0.01) as carcasses became heavier. Carcass weight affected carcass quality (all carcass quality parameters studied were higher in the heavier carcasses), whereas meat quality varied little as a result the small variation between carcass weights in sucking lambs.