YThe enrichment of chicken meat with omega-3 fatty acids by dietary fish oil or its mixture with rapeseed or flaxseed-Effect of feeding duration Dietary fish oil, flaxseed, and rapeseed and n-3 enriched broiler meat

The consumption of chicken meat has steadily increased in recent decades, thereby making meat enriched with long-chain polyunsaturated fatty acids (LC-PUFA) an important delivery route of this nutrient to humans. This study aimed to evaluate how feeding duration of a diet with fish oil and flaxseed or rapeseed can enhance broiler meat with n-3 fatty acids (FA). One hundred and twenty-three 15-day-old female broilers Ross 308 were housed individually and randomly allocated to four groups: control (15 birds), and three experimental groups (36 birds each) that were each divided into three subgroups of 12 birds. Four diets differing in fat composition were prepared. Lard was the source of supplementary fat in diet L; in the experimental diets, fat was derived from fish oil (FO, 10 g kg (-1) diet) and either lard (LFO), flaxseed (FFO), or rapeseed (RFO) in amounts appropriate to produce fat levels similar to those in the control diet. Diets were cold-pelleted and fed until slaughter at 36 days of age. The control group was fed the L diet throughout the study, whereas birds in the experimental groups were fed the L diet until it was substituted by the experimental diets for one, two, or three weeks preceding slaughter. The performance of all groups did not differ from the control, but within the experimental groups, LFO birds had a higher body weight gain because of higher feed intake. RFO birds had a higher thyroid weight (P < 0.02). The levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in breast and thigh meat lipids increased in groups fed the experimental diets as compared to the control. There were substantial increases in alpha-linolenic acid levels and a lower PUFAn-6/n-3 ratio in birds fed the FFO diet as compared to the RFO and LFO diets (P<0.001). Results indicated that one week of feeding the experimental diets was sufficient to enrich breast meat with LC-PUFA, whereas two weeks were needed to effectively enrich thigh meat with these FA. Thus, the meat of broilers fed diets with fish oil and either flaxseed or rapeseed over a period of two weeks before slaughter can be labeled as "high in omega-3 fatty acids." A 100g portion of such breast or thigh meat would provide on average 33% and 15.5%, respectively, of the recommended daily intake of EPA and DHA for humans, and therefore make enriched chicken meat a superior source of LC-PUFA than lean fish meat. (C) 2016 Elsevier B.V. All rights reserved.