Dehydroepiandrosterone and cortisol/dehydroepiandrosterone ratios in dairy cattle with postpartum metritis

Dehydroepiandrosterone (DHEA), a C19 steroid synthesized predominantly by the adrenal cortex, and its sulfated precursor (DHEAS) has antiglucocorticoid and immunoprotective properties. DHEA is important in modulating inflammatory responses; therefore, we hypothesized that DHEA concentrations might be altered in bovine postpartum metritis. DHEA, DHEAS, the cortisol/DHEA-ratio (C/D-ratio) and the DHEAS/DHEA ratio were determined in cows with and without clinical metritis subcategorized by the blood leukocyte numbers. Blood from the coccygeal vein of 37 pluriparous Holstein-Friesian cows was sampled 8.8±0.9days (mean±SE) after calving. Based on clinical signs of metritis and leukocyte numbers (normal range 5-10×10⁶/μl), cows were classified as healthy with leukocyte numbers in the reference range (leukocyte normal; LNH=5954.17±302.4/μl); suffering from metritis with normal leukocyte counts (LNM=7422.22±774.74/μl); or metritis with leukopenia (LLM=3950±284.31/μl P<0.01). Cows with metritis had higher DHEA concentrations than healthy cows (P<0.05). Notably, cows with both metritis and leukopenia displayed higher DHEA concentrations than cows with metritis and normal leukocyte numbers (DHEA LLM 8.15±3.09 vs. LNM 4.09±1.82ng/ml, P<0.05). Cows with metritis and leukopenia also had lower C/D-ratios than healthy cows. In conclusion, DHEA and the cortisol/DHEA-ratio could represent an anti-inflammatory signal during prolonged inflammation of the reproductive tract in dairy cattle and may be a biomarker or prognostic indicator for evaluating disease severity, as seen in serious chronic illnesses in other species.