The role of route of vitamin E administration on the plasma antioxidant activity and lipid peroxidation in newborn calves.

The aim of our study was to evaluate plasma values of alpha-tocopherol, malondialdehyde (MDA) and antioxidant activity after a single-dose administration of vitamin E as intramuscular injection, oral supplementation and intramuscular injection plus oral supplementation at 4 hr after birth. Thirty calves were bled at birth and assigned to treatments as follows: control (n = 8), intramuscular injection (40 IU/kg, n = 7), oral supplementation (25 IU/kg, n = 7) and intramuscular injection (20 IU/kg) plus oral supplementation (12.5 IU/kg, n = 8). Blood was collected at 12 and 24 hr after birth and plasma alpha-tocopherol, MDA and antioxidant activity values were determined. Results showed that no changes in MDA values were observed after oral administration (P > 0.05). However, antioxidant activity values showed an increase at both 12 (9.57 +/- 0.65 mmol/l) and 24 hr (10.42 +/- 0.54 mmol/l) after birth when compared to control (3.73 +/- 0.75 mmol/l). Injection with or without oral supplementation increased serum antioxidant activity values at 12 (about 102%, 46%) and 24 hr (94%, 115%) after birth, when compared to control. In addition, MDA values were found to be lower in those animals receiving an injection of vitamin E or injection plus oral supplementation of vitamin E as compared to control at both time-points (P < 0.001). Injection of vitamin E provided beneficial effects to plasma antioxidant activity and MDA values. Therefore, injection may be the best method of vitamin E administration in newborn calves for protecting them in the stressful postnatal condition.