R. Bras. Zootec.. 15/Oct/2018;47:e20170333.
Fatty acid composition in muscles from lambs fed diets containing agroindustrial co-products
The objective of this study was to evaluate the effects of supplementing diet of lambs with agroindustrial co-products on the nutritional quality of meat fat and study the variation of fat quality parameters based on the type of muscle. Twenty lambs were distributed into four experimental groups and fed a control diet or diets containing cottonseed, sunflower meal, and castor cake. After 106 experimental days, the animals were slaughtered. Samples of Biceps femoris, Longissimus dorsi, Semimembranosus, and Triceps brachii muscles were taken for fatty acid and cholesterol analyses. Castor cake and sunflower meal diets produced meats with lower levels of n-6 polyunsaturated fatty acids (PUFA) compared with the control diet. Castor cake diet contributed to tissue reduction of n-3 PUFA. Lower conjugated linoleic acid concentration and polyunsaturated:saturated fatty acid (P:S) ratio and higher saturated fatty acids content and Thrombogenicity Index were observed in Longissimus dorsi meat. Of the co-products studied, although castor cake diet reduced cholesterol levels in Biceps femoris muscle, sunflower meal was identified as the preferred choice for lamb feeding, since it reduced n-6 PUFA without, however, decreasing n-3 PUFA. Longissimus dorsi meat had the lowest fat quality indexes. The more oxidative muscles, such as Biceps femoris, tend to generate meats with higher cholesterol concentrations.