Physico-chemical characteristics of carcass and meat Manchego-breed suckling lambs slaughtered at different weights.

Forty-nine Manchego-breed lambs raised exclusively on their dams' milk until slaughter were used in this study. The effects of gender and slaughter weight (10, 12 and 14 kg) on carcass fatness, meat quality and the fatty acid composition of their fat were studied. Fatness, and in particular dorsal-fat thickness (P⩽0.01), increased with live weight. The effect of gender was even greater (P⩽0.001), as female lambs presented the highest fatness values for all parameters studied. The smallest drop in m. longissimus pH values was seen in the lowest-weight (10 kg) lambs. These same lambs displayed the highest L* value and thus the lightest colour. Fatty acid composition, which was not influenced by live weight, was affected by gender. The subcutaneous fat of female lambs contained more linolenic acid (C18:3) (P⩽0.01) and a greater proportion of polyunsaturated fatty acids than that of male lambs (P⩽0.001). Likewise, the intramuscular fat of female lambs displayed a greater proportion of monounsaturated fatty acids (P⩽0.001) than that of male lambs.