ABSTRACT
BACKGROUND: The aim of the study was to evaluate oxidant/antioxidant status in 21 Holstein dairy cows with metritis compared to 8 healthy controls. Blood samples were taken during the first 21 days postpartum. Malondialdehyde (MDA), a marker of oxidative stress, total antioxidant status (TAS) and antioxidant parameters such as glutathione peroxidase (GPx), selenium (Se), vitamins A and E and beta-carotene were determined from all cows. The differences in beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), calcium, bilirubin concentrations and aspartate aminotransferase (AST) activity were also monitored, as were milk production and milk composition. Metritis was defined by an unpleasant discharge of varying color (milky-grey/brown/sanguineous) and consistency (muco-purulent/purulent/watery) and by the presence of increased temperature (> 38.5 °C) in cows within 21 days postpartum. Rectal examination revealed increased uterine size, thickened uterine wall and increased uterine tone. The affected cows had significantly reduced daily milk production. Additionally, hematological parameters and haptoglobin concentration were also measured in metritic cows. RESULTS: Higher MDA concentration (P < 0.001) was recorded in cows with metritis, while vitamin A and vitamin E concentrations were lower (P < 0.01) compared to healthy cows. Higher BHB (P < 0.05), NEFA (P < 0.05), AST (P < 0.05) and bilirubin (P < 0.001) concentrations was recorded in cows with metritis as compared to the control group. Significant differences in beta-carotene concentration, GPx activity, and Se, TAS and Ca concentrations in cows with metritis compared to control group were not observed in the present study (P > 0.05). Milk production was decreased in the cows with metritis (P < 0.001) and alterations in milk composition were also observed in metritic cows as compared to healthy cows. CONCLUSIONS: The results of the study showed that cows with metritis in early postpartum are exposed to a higher degree of oxidative stress and that the incidence of metritis can negatively affect milk production in dairy cows.