Fatty acid composition of adipose depots of suckling lambs raised under different production systems

Forty-nine male Talaverana-breed suckling lambs slaughtered at 14 kg live w eight were used to study the fatty acid composition of adipose depots of la mbs raised under different management systems (pasture or drylot) and diets (maternal milk with or without a concentrate supplement). Drylot lambs dis played a higher fatness score, in addition to greater dorsal fat thickness; these parameters corresponded with a greater percentage of total fat at di ssection. Addition of concentrate to the diet did not modify carcass fatnes s. Drylot lambs presented higher proportions of oleic acid (C18:1) and mono unsaturated fatty acids (MUFA) and lower linolenic acid (C18:3) values in s ubcutaneous and intramuscular fat (muscle longissimus thoracis). The subcut aneous fat of these lambs thus displayed a higher n-6/n-3 PUFA ratio (C18:2 /C18:3) than that of pasture-raised ones. Concentrate in the diet of both p asture and drylot lambs resulted in higher linoleic fatty acid (C18:2) and PUFA values and a greater PUFA/SFA ratio in intramuscular fat than the corr esponding values of lambs which consumed maternal milk alone. Loin displaye d a higher percentage of subcutaneous and intramuscular chemical fat than l eg. Compared with intramuscular leg fat (muscle quadriceps femoris), intram uscular loin fat (muscle longissimus thoracis) had lower oleic acid (C18:1) and MUFA values, higher PUFA values and a higher PUFA/SFA ratio, due to gr eater linolenic acid (C18:3) levels. (C) 2001 Elsevier Science Ltd. All rig hts reserved.