Oral fish oil gavage alters relative fatty acid composition across brain regions in broiler chickens.

Long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), play important roles in brain structure and function, but their short-term regional distribution in the avian brain remains unclear. This study evaluated whether oral fish oil (FO) administration alters relative fatty acid composition and neuropeptide Y (NPY) mRNA expression in different brain regions of broiler chickens. Forty 30-day-old Ross 308 male broilers were assigned to receive either corn oil (CT) or FO (2 mL/kg body weight/day) by oral gavage for 10 consecutive days. At the end of the experiment, the diencephalon, brainstem, telencephalon, cerebellum, and mesencephalon were collected for fatty acid and gene expression analyses, and serum biochemical variables were determined. Fish oil did not affect feed intake, body weight gain, serum glucose, triglycerides, HDL cholesterol, calcium, phosphorus, or interleukin-6 concentrations (P > 0.05). In contrast, FO was associated with region-dependent shifts in relative brain fatty acid composition. The telencephalon showed higher relative proportions of EPA, DHA, and total PUFA, whereas the cerebellum showed a higher relative EPA proportion and a nonsignificant tendency toward a higher DHA proportion. Relative EPA and DHA proportions were lower in the brainstem and unchanged in the diencephalon and mesencephalon. Fish oil altered relative fatty acid composition and NPY expression in a brain-region-dependent manner; however, the NPY responses did not consistently parallel EPA/DHA changes and were not associated with altered feed intake.