A study of lipid peroxidation and vitamin E in dairy cows with hepatic insufficiency.

Sixteen dairy cows were studied to assess the status of the natural antioxidant vitamin E and lipid peroxidation in their livers. Cows with liver failure (n = 7) showed clinical signs of a hepatic encephalopathy and had the following values of selected blood indices: AST > 80 U/l and GLDH > 15 U/l in serum, and venous plasma ammonia > 35 mmol/l. The control group (n = 9) consisted of dairy cows which were recovering from surgery (omentopexy) and were free of any health complications. Blood was analysed for alpha-tocopherol, aspartate aminotransferase, glutamate dehydrogenase, gamma-glutamyl transferase, total bilirubin, ammonia, cholesterol, albumin, free fatty acids, glucose, and beta-hydroxybutyrate. Alpha-tocopherol, triglyceride and malondialdehyde were measured in wet liver tissue. The cows with hepatic failure were clearly low in alpha-tocopherol and had significantly lower (P < 0.01) plasma alpha-tocopherol than the controls. Both liver triglycerides and MDA were higher (P < 0.05) in the cows with fatty livers. It is concluded that the cows with liver failure had an increase in the intensity of hepatic lipoperoxidative processes and a low antioxidative status, which should be taken into consideration in cases where treatment of the disease is proposed.