Effect of type of suckling and polyunsaturated fatty acid use on lamb production. 2. Chemical and fatty acid composition of raw and cooked meat

This study was carried out in order to examine the chemical and fatty acid composition of raw and cooked meat obtained from lambs raised under mothers or reared by artificial suckling with acidified milk replacers with or without polyunsaturated fatty acid (PUFA) supplementation. Meat samples were taken from twenty Gentile di Puglia male lambs subjected to the following feeding treatments: the control group received only maternal milk (MM, n.=6) while two groups were reared by artificial suckling with an acidified milk replacer (MR, n.=7) or with an acidified milk replacer supplemented with 10 ml/l of a PUFA enriched oil (MR+PUFA, n.=7). Lambs were slaughtered at 45 days of age. After 24 hours of refrigeration at 4 °C, the lumbar region was dissected from each right half-carcass and split into pieces, one of which was used raw while the other was cooked in a ventilated electric oven at 180 °C until an internal temperature of 75 °C was reached. Chemical and fatty acid analysis were performed on raw and cooked meat, while only raw meat was assessed for cholesterol. Cooking losses were also evaluated. Meat obtained from MR+PUFA fed lambs contained more fat (P<0.01) and less protein (P<0.05) than MM lambs. Nursing under mothers increased the total amount of saturated fatty acids (SFA), compared with both the MR group (P<0.05) and to the MR+PUFA one (P<0.01). In MM meat samples, fewer PUFAs (P<0.01) and omega-6 fatty acids (P<0.01) were found in comparison with both MR diets. The highest PUFA/SFA ratio of meat was recorded for the MR+PUFA group (0.27), with statistical differences respect to the MR group (0.21; P<0.05) and to the MM one (0.14; P<0.01). Lambs raised with maternal milk produced meat containing more cholesterol than the MR+PUFA group (85.89 vs 76.26 mg/100 g; P<0.05). The atherogenicity index of meat was higher following natural rearing in comparison with the MR+PUFA treatment (1.34 vs 1.05; P<0.05), while the PCL/PCE ratio was significantly higher in MR+PUFA samples than in both MM and MR ones (0.93 vs 0.77 and 0.76, respectively; P<0.05). Cooking cancelled the differences between treatments with regard to the all the dietetic parameters evaluated. In conclusion, artificial suckling with acidified milk replacers improves some meat quality features. Supplementation of milk replacers with PUFAs, although in a limited way, may improve the dietetic properties of lamb meat.