Fecal lipidomic biomarkers in production-related metabolic disease (PRMD)-resistant and susceptible dairy cows

Abstract

Although it is known that the highest incidence for most production-related metabolic diseases (PRMDs; ie, milk fever, fatty liver, ketosis, LDA, mastitis, and infections) occurs within 60 days-in-milk (DIM), PRMD incidence has not been altered by transition diets, dietary CAD, and avoidance of over-conditioning. Economic returns are significantly affected by PRMDs because of altered milk composition or decreased production, conception, life expectancy, and cull value. The risk for PRMD has been correlated with increased serum FFA, NEFA, TG, and PHBA concentrations and hepatic TG-to-glycogen ratio. Regulation of hepatic metabolism is dynamic and can differ between similarly managed transition cows. The difference in fecal carbon stable isotopes (13C/12C ratio, 813C) measured 3 weeks prepartum and at parturition predicted 66% of cows resistant to or at risk for PRMDs in the subsequent lactation, with susceptible cows having a more depleted isotopic signature correlated with mobilizing endogenous lipid and protein stores for maintenance needs. Finding these differences prior to PRMD onset prompted investigation of fecal lipids present at the beginning of the transition period and at parturition. The objectives of this study were to determine the fecal lipid profiles for PRMD-resistant and PMRD-susceptible cows, and to determine if PRMD-susceptible cows have unique fecal lipidome biomarkers.