Fatty acid profiles and omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis capacity of three dual purpose chicken breeds

Abstract

Westernized societies ingest an unhealthy high dietary omega-6/omega-3 fatty acid ratio of 20:1 or even higher. Seafood is the primary source of omega-3 long chain polyunsaturated fatty acids (LC-PUFA) for humans, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are involved in a plethora of physiological and health-related processes. However, the production of marine organisms with aquafeed formulations based on marine ingredients leads to serious environmental impacts on global pelagic fish resources, resulting in an unsustainable activity. The present study aims to gain further insight into the metabolism of fatty acids in chicken as a potential supply for omega-3 LC-PUFA. To this purpose, lipid classes and fatty acid profiles of thighs and hepatocytes, and the modification of [1-14C]18:3n-3 by hepatocytes isolated from three dual-purpose chicken breeds adapted to free-range culture systems were determined. Arachidonic acid highly accumulated in thighs meat (7.16–8.79 %) despite being barely supplied in the diet, with DHA (1.22–1.71 %) and n-3 docosapentaenoic acid (DPA, 22:5n-3; 1.02–1.14 %) being also relevant. Our experimental design with radiolabeled fatty acids was validated for the first time in terrestrial vertebrates. Chicken hepatocytes incubated with [1-14C]18:3n-3 produced a wide variety of C18-C24 intermediates demonstrating that the set of fatty acyl desaturases and elongases enzymes necessary to metabolize dietary C18 precursors are active for the production of LC-PUFA, including EPA, n-3 DPA and DHA.