Influence of genotype and slaughtering age on meat from Altamurana and Trimeticcio lambs

The effect of genotype and age at slaughter (42 days vs. 70 days) on growth, carcass measurements and meat quality were evaluated in 40 Altamurana and Trimeticcio lambs. Meat quality (as defined by chemical and nutritional composition) were measured on two different muscles (longissimus dorsi, LD, semimembranosus, SM). Trimeticcio lambs were heavier at birth (P < 0.01) and had higher daily gains than Altamurana animals during the 0–42 days period, whereas no differences in growth rate were found during the 0–70 days period. Carcass measurements pointed out that Trimeticcio lambs had higher width of chest and width of pelvis and gave meat with more muscle and less bone than Altamurana lambs. Protein content was significantly higher in meat from Altamurana than from Trimeticcio lambs. The fat content of SM muscle was significantly higher in Trimeticcio than in Altamurana. The earlier slaughtering age produced an improvement in fatty acid composition with a lower percentage of total saturated fatty acids and higher amount of total polyunsaturated fatty acids. In addition, meat from younger lambs displayed lower thrombogenic index and ω-6/ω-3 ratio and higher PUFA/SFA ratio than meat from lambs slaughtered at 70 days.