Serum changes following the feeding of ragwort ( Senecio jacobea) to calves

Abstract

Five calves were fed ragwort incorporated into the feed at levels of 1·2, 0·8 and 0·4 lb. per day. All the calves died or were killed in a moribund state with severe hepatic lesions. None of them showed a significant alteration in total serum protein concentration. Only 2 calves, one that received 0·8 lb. and one that received 0·4 lb. ragwort per day, showed a fall in serum albumin concentration and a rise in serum globulin. The 3 calves which received the higher doses of ragwort developed a terminal hyperbilirubinaemia. All calves showed an increase in the concentration of the 4 enzymes, G.O.T., G.D., S.D. and O.C.T., in the serum. In the calves dosed at the 2 higher rates, the rises were concurrent. In the 2 calves receiving smaller amounts of ragwort, different enzymes leaked into the serum at different times after the commencement of ragwort feeding. In all animals, structural changes in the liver were minimal at the time of initial enzyme release whereas immediately before death, at which time there were marked liver lesions, serum enzyme concentration was in many instances within the normal range.