Oxidative stress indices in the erythrocytes from lactating cows after treatment for subclinical ketosis with antioxidant incorporated in the therapeutic regime.

The present investigation was carried out to assess the erythrocytic oxidative stress indices such as lipid peroxides level and activities of antioxidant enzymes such as superoxide dismutase and catalase, and some hematological parameters after treatment of subclinically ketotic lactating cows with antioxidants, vitamin E and selenium, incorporated in conventional treatment regimen. The study was carried out using lactating cows reared in small dairy herds in and around Bhubaneswar. Out of 250 urine samples examined, 42 cows were diagnosed positive for subclinical ketosis with an overall incidence of 16.8%. Blood samples were collected on day 0 (before treatment) and treatment was initiated on day 1 and the second sampling was carried out on day 7. The hematological parameters improved significantly following treatment as compared to pre-treatment level (day 0). A significant (P < 0.05) improvement was observed on day 7 with respect to hemoglobin level (8.66 +/- 0.23 vs. 9.12 +/- 0.14 gm/dl) and packed cell volume (29.7 +/- 0.56 vs. 31.1 +/- 0.50%) in the group given routine treatment along with antioxidants. The comparison of mean lipid peroxides level before (day 0) and after treatment (day 7) revealed a significant difference in group I (routine treatment, P < 0.05) and group II (routine treatment plus antioxidants, P < 0.01). The maximum reduction in SOD activity was recorded in group II animals after treatment with conventional regimes along with supplemented antioxidants (1.29 +/- 0.08 against 1.89 +/- 0.15 units/ mg of Hb, P < 0.01). The mean value of SOD activity recorded in group III animals kept as non-treated positive control (PC) on day 7 (2.59 +/- 0.14 units/mg of Hb) was significantly (P < 0.05) higher than the mean level recorded on day 0 (1.91 +/- 0.31 units/mg of Hb). An almost similar trend was observed in erythrocytic catalase activity where there was a significant (P < 0.05) reduction in catalase activity in the group II (RT+A) but there was no significant increase in catalase activity in non-treated positive control (PC) animals.