[Changes in enzyme activity induced by experimental aflatoxicosis in dairy cows]

The activities of GOT, GPT, LDH, gamma-glutamyltranspeptidase (gamma-GTP), alkaline phosphatase (AP), glutamate dehydrogenase (GLDH) and the concentrations of bilirubin in blood plasma after a single intraruminal application of aflatoxins were studied in four dairy cows. The maximum changes in the activities of the enzymes and the maximum bilirubin concentration in plasma were obtained in the first two to three days following the application of aflatoxins. The statistically significant increase of GOT activity, compared with activity before the application of aflatoxins, persisted until the 23rd day; in the case of LDH and GLDH the increase persisted until the 38th day from the application of aflatoxins. The activities of gamma-GTP and AP were slightly higher even on the 50th day. The increased concentration of bilirubin in plasma lasted until the 23rd day from aflatoxin application. The increased activities of enzymes testify to an impaired function of the liver, which is also proved by the specific enzymes GLDH, gamma-GTP, by increased bilirubin levels, and by histological changes known from literature. The evaluation of enzymatic activities and bilirubin concentration in plasma can make a valuable contribution to correct diagnosis of aflatoxicoses in cattle.