EXPERIMENTAL POISONING OF CATTLE AND CHICKS BY 5 SENECIO SPECIES

Abstract

The toxicity of 5 species of Senecio was studied experimentally in cattle and chicks. The chicks were fed during 60 days with a ration containing 5% of dry plant. All Senecio species were toxic in the following sequence of toxicity: S. brasiliensis, S. heterotrichius, S. cisplatinus, S. selloi and S. leptolobus. To cattle the plants were administrated at 22.5, 45, 90 and 180g per kg of body weight in a period from 15 to 39 days. S. leptolobus was not toxic at these doses. The other 4 species were toxic indicating its participation in the occurrence of seneciosis in cattle in southern Brazil. The determination of the alkaloid content showed integerrimine and retrorsine (0.31% of dry weight) in S. brasiliensis and S. heterotrichius (0.19%); retrorsine and senecionine in S. cisplatinus (0.16%) and S. selloi (0.10%) and neosenkirkine and florosenine in S. leptolobus (0.005%). Integerrimine, retrorsine, mixtures of integerrimine-retrorsine and neosenkirkine-florosenine were fed to chicken at 50mg per kg of food during 45 days. The mixture of neosenkirkine-florosenine was less toxic than the others. The alkaloids showed less toxicity than the dried plants, due probably to the loss of alkaloids during extraction or drying procedure or storage conditions of the plants.