Fatty acids in intramuscular fat of Ile de France lambs in two different production systems

Abstract

The fatty acid (FA) composition in the intramuscular fat (IMF) of the musculus longissimus dorsi (MLD) of Ile de France purebred lambs in two different production systems in Slovakia was evaluated using gas chromatography. In the first production system, lambs and ewes were assigned to pasture without access to concentrates (P). In the second system, lambs and ewes were confined indoors with hay/silage and access to concentrates (S). An analysis of variance with the following factors was employed: production system, sex, and production system-sex interactions. The proportions of arachidonic, eicosapentaeonic, docosapentaeonic, and docosahexaenoic FAs, i.e. long-chain polyunsaturated FA (PUFA), were significantly higher in P lambs (1.83, 0.82, 0.92, 0.29 g 100 g ${}^{-1}$ FAME, respectively) than in S lambs (0.45, 0.14, 0.30, 0.09 g 100 g ${}^{-1}$ FAME, respectively). The proportions of conjugated linoleic acid (CLA), n-6 PUFA, n-3 PUFA, and essential FA (linoleic and $\alpha$ -linolenic) were also significantly higher in P lambs (2.10, 8.50, 4.55, and 8.80 g 100 g ${}^{-1}$ FAME, respectively) than in S lambs (0.65, 3.27, 1.50, and 3.64 g 100 g ${}^{-1}$ FAME, respectively). The proportions of palmitic acid and myristic acid as important individual saturated FAs (SFA) were significantly higher in S lambs (28.51 and 8.30 g 100 g ${}^{-1}$ FAME, respectively) than in P lambs (21.80 and 5.63 g 100 g ${}^{-1}$ FAME, respectively). The proportion of all SFAs was also significantly higher in S lambs (57.87 g 100 g ${}^{-1}$ FAME) than in P lambs (48.70 g 100 g ${}^{-1}$ FAME). From a nutrition and human health point of view (i.e. higher proportions of PUFA, CLA, and essential FAs and lower proportions of SFAs), meat from P lambs was found to be more favourable and would be more highly recommended for consumption.