Effects of extruded linseed on muscle physicochemical characteristics and fatty acid composition of lambs

Effects of extruded linseed incorporation on meat quality and intramuscular fat fatty acids (FAs) composition were studied on 36 lambs from Tunisian local breed, Queue Fine de l'Ouest. All lambs were male with an average body weight of 21.3 kg at the beginning of the experiment. Animals were divided into three groups of 12 lambs each, receiving hay ad-libitum and one of three concentrates containing 0 (Control), 15 (L15) and 30 (L30) per cent of extruded linseed. At the end of the experiment which lasted for 85 days, all the lambs were slaughtered. Samples of longissimus dorsi muscle were taken for meat quality measurements and FA determination. No effects of linseed on lamb growth were observed. The cooking loss, meat pH and colour parameters were similar for all diets. Linseed supplementation increased protein content (p=0.07) and decreased fat content (p=0.06) in the meat. However, the intramuscular FA composition was affected by linseed supplementation. The polyunsaturated FA to saturated FA ratio (PUFA/SFA) was higher for L15 and L30 groups than for Control (p<0.01). The content of C18:3 and the sum of polyunsaturated FA (PUFA) were higher for L15 and L30 groups than for Control one (p<0.05). PUFA n-3 contents significantly increased with linseed incorporation (0.70, 3.56 and 3.26 for Control, L15 and L30, respectively). In contrast, n-6:n-3 ratio significantly decreased from 5.23 for Control to 0.71 and 1.1 for L15 and L30, respectively.