Comparative Analysis of Two Dietary Saturated Fat Types on Metabolite Profiles Crossing the Blood-Brain Barrier of...

Background: The dorsal raphe nucleus (DRN) produces and distributes serotonin, while the hypothalamus (HYP) uses serotonergic signals to regulate physiological processes in chickens. Coconut oil (COCO), rich in medium-chain fatty acids, is rapidly absorbed without re-esterification. Methods: Day-old broilers (Ross 708 male, n = 160) were distributed into two dietary treatments with five replicates of 16 birds each. The birds were fed a corn-soybean meal (SBM) basal diet supplemented with 3% of poultry fat (CON) or coconut oil (COCO). The body-weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were recorded over a 3-week period, and the data were subjected to a t-test. Untargeted metabolomic analysis by high-performance liquid chromatography (HPLC-MS) was used to evaluate the influence of the type of dietary fat on metabolite profiles in the DRN, HYP, and plasma of broiler chickens. Principal component analysis (PCA) was used to identify unique metabolites, and ANOVA was used to identify the metabolites that were significantly abundant (p < 0.05). The metabolites were then annotated using the KEGG and HMDB databases. Results: Birds in the COCO treatment gained more weight on average (0.8446 kg/bird) than birds in the CON group (0.8132 kg/bird; p = 0.0496). Five metabolites associated with multiple significant cellular processes, such as brain function, energy metabolism, and neurotransmission, showed similar differential expression patterns, while two metabolic pathways (butanoate metabolism and alanine, aspartate and glutamate metabolism) were identified. Conclusions: The dietary inclusion of COCO improves BWG in poultry and enhances their overall well-being by modulating metabolite profiles, supporting neurotransmission, and enriching the metabolic pathways essential for growth and brain function.