Oxidative stress and trace elements before and after treatment in dairy cows with clinical and subclinical endometritis

The objective of this study was to investigate if changes in oxidative stress and trace element concentrations in postpartum cows can promote endometritis and may influence the issue of treatment. For that, oxidative stress markers and trace element concentrations were determined in sera from cows suffering from clinical or subclinical endometritis (CE and SE groups, n = 30 in each group) at the time of clinical and cytological diagnosis and 7 days after treatment and compared with healthy cows (n = 30). Compared to the controls, serum TAS (total antioxidant status) values were significantly depressed in all diseased cows whereas MDA (malondialdehyde) concentrations were dramatically increased, mainly in animals with clinical endometritis. Additionally, serum copper and zinc concentrations were significantly decreased in cows with clinical endometritis. Significantly higher initial TAS values were observed in CE cows for which treatment was successful than in affected cows not cured 7 days after. After successful treatment for clinical endometritis, significantly increased copper concentrations were observed and serum MDA concentrations have also significantly decreased when treatment was successful in subclinically and clinically affected cows 7 days after. These results suggest that decreases in antioxidant capacity and in trace elements (copper and zinc) could be associated with subsequent oxidative stress and increased susceptibility to endometritis and that endometritis resolution was related to the antioxidant and copper status and to decrease in oxidative stress.