Longer consumption of flaxseed oil enhances n‐3 fatty acid content of chicken meat and expression of FADS2 gene

The aim of this study was to evaluate the effect of different durations of flaxseed oil consumption on broiler performance, fatty acid content of meat and expression of FADS2 gene in the liver of chicken. A total of 336 unsexed day old chicks were randomly assigned to 7 dietary treatments with 4 replicates of 12 chickens in each. Body weight, weight gain, feed intake and feed conversion ratio were not affected by dietary treatments. Longer consumption of flaxseed oil resulted in higher deposition of long chain n‐3 fatty acids in broiler breast and thigh (P < 0.05). Regression analysis showed that feeding broilers with diet enriched with flaxseed oil 17 and 7 days prior to slaughter for breast and thigh respectively, is enough for producing n‐3 labeled meat. Weekly replacement of oil source of diet (soybean oil) with flaxseed oil increased expression of FADS2 gene. To incorporate enough n‐3 fatty acids into chicken meat through addition of flaxseed oil to broiler diet and to maximize de novo long chain n‐3 fatty acid synthesis in broiler body, we recommend adding flaxseed oil to broiler diets 17 days prior to slaughter. Practical applications: Omega‐3 enrichment of broiler chickens depends on both nutrition and gene expression. Flaxseed oil is an omega‐3 oil source that can be supplemented to broiler diet to enrich chicken meat with the beneficial n‐3 fatty acids. However, adding such oil sources to broiler rations is restricted because of their negative effects on broiler performance and meat quality. Therefore, shorter period of such oil sources consumption is preferred. Flaxseed oil consumption can affect gene expression too. Thus, it is necessary to determine the optimum duration of flaxseed oil supplementation to broiler diets to produce omega‐3 labeled chicken using both nutrition and gene expression. Flaxseed oil consumption can affect fatty acid profile of chicken meat through manipulation of fatty acid deposition, de novo fatty acid synthesis, fatty acid oxidation and expression of genes involved in fatty acid metabolism. To incorporate enough n‐3 fatty acids into chicken, providing at least 3 g n‐3 fatty acid per kilogram of meat, by adding flaxseed oil to broiler diet, we recommend adding flaxseed oil to broiler diets 17 days prior to slaughter.