The present experiment was conducted to study effects of broiler diets supplementation with soybean oil (SBO) (1.5 or 3%), linseed oil (LSO) (1.5 or 3%), compared with (3%) corn oil (CO) on growth performance
(GP), fatty acids composition (%) of breast and thigh muscles, liver tissue and morphological changes in liver, duodenum and biceps femoris muscle. The experiment was carried on 160 one-day old chicks randomly allocated to five groups and fed for 6 weeks. The obtained results indicated that feeding of LSO 3%-diet improves final BW and FCR of broilers compared with the groups fed CO or SBO-supplemented diets. The highest levels of α-linolenic acid (ALA), arachidonic acid and docosahexaenoic acid (DHA), total n-3 fatty acids and low levels of linoleic, total MUSF and low ratio of n-6:n-3 (0.52) were detected in the breast muscle of the broiler group fed the 3% LSO-supplemented diet compared to the broiler group fed the CO (3%) or SBO (1.5 and 3%) supplemented diets. Higher levels of linoleic, ALA, arachidonic acid, DHA and total n-3 fatty acids with low n-6:n-3 ratio (0.42) were detected in the thigh muscle of broiler fed LSO supplemented diet (3%). Also,
high levels of ALA, DHA, total n-3 fatty acids were detected in liver tissue of the broilers fed the 3% LSO supplemented diet. Microscopically, mild lipid droplet accumulation was noticed in liver tissues of broilers fed LSO or SBO supplemented diets (1.5%). Nonsignificant increase was statistically recorded inhepatocyte/nuclear ratio (N/N) in broilers group fed LSO and SBO supplemented diets. Longer enterocyte height (EH), higher diameter area and perimeter of cross sectional biceps femoris muscle fibers were seen in chicken groups fed
LSO or SBO supplemented diets (3%). In conclusion, broiler chickens diet supplemented with LSO improved BW gain, FCR and precipitation of total omega-3 fatty acids in breast and thigh muscles with no morphological changes in liver, duodenum and biceps femoris muscles.