The effects of dietary fats on the fatty acid composition of broiler tissues

Male and female broilers were fed a basal diet supplemented with 3% and 13% beef tallow, and 3% and 13% peanut oil. Lipids were extracted from skin, white meat, and dark meat. The lipids were separated Into neutral and phospholipid fractions, and the fatty acid compositions of the two fractions were determined using GLC for each dietary treatment. The higher levels of dietary fat produced a higher content of total lipids and neutral lipids In different tissues of broilers. The identification of gas liquid chromatography peaks of methyl esters of fatty acids was done using derived retention time systems and an additional system was devised and named MECL (n:2w6). Phospholipids were generally higher in 18:0 and 20:4w6 than neutral lipids, whereas neutral lipids contained higher amounts of 18:1w9. Phospholipids showed characteristic fatty acid patterns In different tissues and dietary treatments. Each lipid fraction tended to assume the fatty acid pattern of the dietary fat treatment with neutral lipids being affected far more than phospholipids. The Intermediate fatty acids of biogenesis of the w6 family of unsaturated fatty acids were observed (20:2w6, 20:3w6, 20:4w6, 22:4w6 and 22:5w6). for the w3 family fatty acids, 18;4w3, 20:5w3, 22:5w3, and 22:6w6 were observed. Fatty acids, 22:2w6, 24:3w6, and 24:4w6 were occasionally observed, and these acids are believed to be derived from 22:2w6, which was contained in small amounts in the vegetable oil diet. The two severely overlapped peaks which were usually observed In the gas liquid chromatography of neutral lipids might contain some other compounds, other than methyl esters of fatty acids. These facts need to be checked further for the importance of fatty acid analysis using GLC.