Effect of dietary fat source on n-3 fatty acid enrichment of broiler meat

Scientific research has shown that there is a relationship between the amount and composition of animal fat in the food and cardiovascular and other diseases in humans. The fatty acid composition of broiler meat can be modified by dietary fat sources. In recent years, one of most important effect of fats to performance and the quality of meat is that related to the ratio of omega 6 (n-6)/omega 3 (n-3) fatty acids in the diet. In poultry diets with fishmeal, fish oil or oil derived from vegetable source increase the content of polyunsaturated fatty acids (PUFA, particularly with n-3 fatty acids) in meat. This study was conducted to observe the effects of different fat sources on accumulation of different fatty acids and on the ratio of n-6 to n-3 fatty acids in broiler meat. In this study, 320 one day old chicks, randomly arranged in 4 replicates (20 chicks per replicate) were assigned to one of four dietary treatments. The birds were fed diets with 6% of added fat. Four diets, containing 6% fish oil (170) (Diet A); 4% FO + 2% linseed oil (LO) (Diet B); 2% FO + 2% LO + 2% sunflower oil (Diet C), and 6% soy oil (Diet D, control) were used. The meat samples were taken on days 21 and 42 of fattening, and meat fatty acid compositions of meat were analyzed. Also, malondialdehyde (MDA) levels were determined. It was observed that the monounsaturated fatty acid (MUFA) level of meat samples of broilers fed Diet A was significantly higher than that of the other groups (p < 0.05). Addition of FO to diet decreased n-6 (p < 0.01) and increased n-3 fatty acid level (p < 0.05). Therefore, n-6/n-3 rates were decreased in meat samples by adding fish oil (p < 0.01). At the end of the study, the levels of polyunsaturated fatty acids, especially EPA and DHA were increased, thereby, n-6 fatty acid level of meat samples was decreased and n-3 level was increased by adding fish oil to the diet (p < 0.001). As a result, addition of fish oil to diet was more effective than vegetable oils on decreasing of n-6/n-3 rate (p < 0.001). However, MDA level was increased according to level of fish oil (p < 0.001).