Fatty acid profile in meat of culling ewes in different feedlot periods fed diets containing levels of inclusion of linseed

Abstract

Linseed plays an important role in animal nutrition as it contains long-chain fatty acids in its composition, which, once absorbed, are incorporated into meat and milk. For evaluate the concentration of fatty acids in the Longissimus dorsi muscle of culling ewes fed diets containing levels of inclusion of linseed, 88 culling ewes were used with an average initial body weight of 37.65 ± 6.98 kg were distributed in a completely randomized design with 12 treatments. Treatments consisted of the interaction between levels of linseed (0, 5, 10, and 15%) and days in feedlot (30, 45, and 60). The most present fatty acids in the composition of the muscle L. dorsi were palmitic (27.32 g 100 g-1) and stearic (17.77 g 100 g-1). Saturated acids remained at low levels as the animals were fed greater levels of linseed, demonstrating the importance of introducing quality foods in animal feeding. Oleic acid was the most present monounsaturated fatty acid, with 40 g 100 g-1. Palmitoleic and elaidic fatty acids increased linearly as the linseed inclusion in the diet was increased. Polyunsaturated acids increased with the presence of linseed in the diet. For the linolenic acid (C18: 3n3), the best result was with inclusion of 10% of linseed in the total diet. All groups of animals that received linseed obtained better n6:n3 ratios, which varied from 1.81 to 4.14. The higher CLA values obtained in this study are related to the higher amounts of inclusion of linseed in the sheep diet, varying from 1.15 to 5.72 g 100 g-1. It is recommended culling ewes supplemented with inclusion of 10% linseed, for 60 days in feedlot, because they comprise a larger number of favorable traits regarding to the profile fatty acids of Longissimus dorsi.