The platelet and plasma proteome and targeted lipidome in postpartum dairy cows with elevated systemic inflammation.

Unregulated, systemic inflammation negatively impacts health and production in dairy cows. Soluble mediators and platelets have been studied for their expansive role in mediating inflammation. Our objectives were to compare the plasma oxylipin and endocannabinoid profiles, and the platelet and plasma proteomic profiles of healthy cows to cows experiencing elevated systemic inflammation as indicated by plasma haptoglobin (Hp) concentrations. Postpartum cows at 3 DIM with plasma Hp concentrations [Formula: see text] 0.50 g/L and no clinical disease were enrolled into the high-inflammation group (n = 8). Cows with plasma Hp concentrations [Formula: see text] 0.1 g/L and no clinical disease were enrolled into the low-inflammation group (n = 8). Targeted lipidomic analysis revealed differences in the plasma oxylipin and endocannabinoid profile between high- and low-inflammation cows. Cows in the high-inflammation group had increased plasma concentrations of the oxylipins 9(S)-HpOTrE, 9(S)-HOTrE, 13(S)-HpOTrE, and 9,10-EpOME, and the endocannabinoid anandamide. In-depth proteomic analysis of platelets between the high- and low-inflammation groups revealed significant differences in protein categories related to platelet granule release and cellular iron uptake. Proteomic outputs from plasma revealed 24 proteins to be different between high and low-inflammation groups, including proteins involved in autophagy and immune mediation. Together, our results indicate that cows experiencing an exacerbated systemic inflammatory response in the postpartum may have impaired disease resistance, and platelets could be contributors to their inflammatory state.