Lipid profile of lamb meat from different genotypes submitted to diets with different energy levels

To assess the influence of genotype and diets with different energy levels on the lipid profile of sheep meat, 54 lambs were used (18 animals from each genotype: Morada Nova, Santa Inez and ½Dorper + ½Santa Inez crossbred), distributed in a completely randomized experimental design in a 3 × 2 factorial arragement (three genotypes and two diets). The animals were submitted to two diets, 2.5 Mcal ME/kg DM and 3.0 Mcal ME/kg DM, receiving feed and water to reach the desired average live weight of 30 kg, when they were slaughtered. Total lipids, cholesterol, phospholipids and fatty acids profile of the Longissimus muscle were assessed. Diet and genotype did not influence the total lipids, cholesterol and phospholipids contents. The diet with the highest energy value presented higher values for the concentration of C12:0, C14:0, C18:0, C19:0, C22:0 acids and monounsaturated fatty acids (MUFA) in relation to that with the lowest energy value. However, for the concentrations of C15:0 acid and polyunsaturated fatty acids (PUFA), the highest values were recorded for diet with the lowest energy value. Genotype and diet influenced significantly the MUFA concentration, in which ½Dorper + ½Santa Inez crossbred genotype and diet with 2.5 Mcal ME/kg DM showed the highest values. Genotype influenced the saturated fatty acids (SFA) concentration, with ½Dorper + ½Santa Inez crossbred obtaining the lowest mean, behavior similar to that observed for PUFA concentrations. Desirable fatty acids (DFA), atherogenicity index as well as PUFA:SFA, MUFA:SFA, (C18:0 + C18:1):C16:0 ratios were influenced by diet and genotype. ½Dorper + ½Santa Inez crossbred and diet with 2.5 Mcal ME/kg DM obtained the best results