FIRST REPORT OF FIELD OUTBREAKS OF ERGOT-ALKALOID TOXICITY IN SOUTH-AFRICA

Outbreaks of clinical disease caused by the ingestion of ergotized Lol ium rigidum (annual ryegrass), which resulted in a substantial loss in production, have been reported. A number of outbreaks of a hypertherm ia syndrome in cattle, characterized by severe loss in milk production , loss of body mass and reduced fertility, are described. In one major outbreak in March to April 1994, a milling company reported that 2 64 6 dairy cows on 29 farms had developed clinical signs. In this outbrea k, significant levels of ergotamine, ergosine, ergocornine and ergocry ptine were found in the milled dairy rations fed to the affected cows, Barley screenings containing ergotized annual-ryegrass seed was ident ified as the toxic component and probable source of the ergot alkaloid s in the ration. The clinical syndrome was reproduced experimentally b y feeding suspected feed to a group of nine high-producing Ayrshire co ws. An outbreak of gangrenous necrosis of the extremities in young cat tle in the winter of 1987 was also suspected of having been caused by ergot alkaloids in grain screenings.