PS8-28. Micro-fused Essential Oil Blend Supplementation Alters the Plasma Metabolome of Sheep.

Abstract We applied untargeted plasma metabolomics to identify metabolic signatures associated with micro-fused essential oil (MEO) supplementation in sheep. Eighteen crossbred Katahdin ewes of approximately (average BW = 25 ± 0.49 kg) were randomly assigned to either an unsupplemented basal diet (CON; n = 9) or a basal diet supplemented with a blend of 4 g/head/day of micro-fused thyme, oregano, and cinnamon essential oils (MEO; n = 9) for a 35-d experimental period. Weekly blood samples were collected 5times. Plasma was prepared by centrifugation and composited for each sheep. Metabolome analysis was conducted using a chemical isotope labeling (CIL)/liquid chromatography–mass spectrometry. A total of 601 metabolite features were detected. Volcano plot analysis identified 38 differentially abundant metabolites (FDR < 0.05): 6 were significantly upregulated in MEO sheep, including: 3,4-dihydroxymandelic acid and 2-oxovaleric acid, while 32 were downregulated, including isoleucine, leukotriene D4, propionic acid and L-ornithine. Biomarker analysis identified gamma-amino-gamma-cyanobutanoic acid, Nocardicin A/Isonocardicin, 2-propylmalic acid, and isoleucine as candidate plasma biomarkers of MEO supplementation (FDR < 0.05; AUC > 0.85). Pathway enrichment analysis identified valine, leucine, and isoleucine degradation as the most significantly enriched pathway, alongside fatty acid elongation in mitochondria, and glutathione metabolism. These results indicate that micro-fused thyme-oregano-cinnamon blend reshapes the plasma metabolome of sheep, with principal effects on branched-chain amino acid catabolism, pro-inflammatory eicosanoid pathways, and lipid metabolism. Validation in a larger cohort of sheep is warranted to confirm these biomarkers.