Pathophysiological Role of Oxidative Stress and Antioxidant Defense in Subclinical Endometritis of Dairy Cows

Background: Subclinical endometritis (SCE) is a prevalent postpartum disorder impairing fertility and contributing to economic loss in dairy herds. Emerging evidence indicates that oxidative stress may mediate endometrial inflammation and delayed uterine involution. This study aimed to characterize systemic oxidative stress and antioxidant status in cows with SCE compared to healthy controls, providing insights into its pathophysiological role. Methods: Blood samples were collected from Holstein cows ۴۵–۶۰ days postpartum diagnosed with SCE based on endometrial cytology (≥۵% PMN, n = ۲۵) and from healthy controls (<۵% PMN, n = ۲۵). Serum malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities were measured spectrophotometrically. Data were analyzed using independent t-tests, and correlations between oxidative markers and PMN percentage were assessed using Pearson’s test. Results: SCE cows showed significantly elevated MDA levels (p < ۰.۰۱) and reduced TAC, SOD, and GPx activities (p < ۰.۰۵). PMN percentage positively correlated with MDA (r = ۰.۶۴, p < ۰.۰۱) and negatively with TAC (r = −۰.۵۸, p < ۰.۰۱). ROC analysis revealed that MDA had good discriminatory power for SCE diagnosis (AUC = ۰.۸۳). Conclusion: These findings suggest that heightened oxidative stress and impaired antioxidant defense contribute to the pathophysiology of SCE. Measurement of oxidative biomarkers, particularly MDA, may aid early diagnosis and guide antioxidant-based therapeutic strategies to improve uterine health and reproductive performance.

کلیدواژه ها:

Oxidative stress ، Antioxidant defense ، Subclinical endometritis ، Dairy cows ، Clinical pathology