Metabolomics Insights Into Nutritional Intervention With Polyphenols in Feedlot Beef Cattle

Polyphenol‐based feed additives have been increasingly used in feedlot diets due to their potential to modulate rumen fermentation and systemic redox and inflammatory responses; however, mechanistic evidence at the systemic level in finishing cattle remains limited. This study evaluated the effects of a polyphenol on the serum metabolites profile of finishing beef cattle. Twenty‐four ½ Angus × ½ Nellore steers fed a high‐concentrate diet were assigned to a control diet or polyphenol mixture at 2 g/animal/day. Blood was collected on days 0 (1 day before the polyphenols supplementation), 20 and 40 after the product was added to the diet, and serum metabolites were quantified by 1 H NMR spectroscopy. Multivariate analyses indicated no clear separation of serum metabolite profiles between treatments at either sampling time. Nevertheless, polyphenol supplementation was associated with higher glycine ( p = 0.005) and lower butyrate ( p < 0.001), with tendencies for lower 3‐hydroxybutyrate, betaine, and O‐phosphocholine ( p ≤ 0.091). From days 20 to 40, 2‐hydroxybutyrate, citrate, methylmalonate, and O‐phosphocholine decreased, whereas glycine increased ( p ≤ 0.047), and a treatment × time interaction was detected for glutamine ( p = 0.023). Pathway enrichment suggested modulation of butyrate metabolism, branched‐chain fatty acid oxidation, ketone body metabolism, mitochondrial electron transport chain, peroxisomal oxidation of phytanic acid, purine metabolism, and ammonia recycling. Supplementation did not significantly affect BW, average daily gain, or fecal consistency. Overall, polyphenol mixture induced discrete but biologically coherent serum metabolome shifts consistent with changes in energy and nitrogen handling and pathways commonly linked to oxidative and inflammatory homeostasis, despite minimal effects on growth performance.