A field outbreak of chronic aflatoxicosis in dairy calves in the western Cape Province

An outbreak of mortality in Friesland dairy calves In which 7 out of 25 calves died in the western Cape Province, Republic of South Africa Is described. Clinical signs included a loss in body mass, staring hair coat, diarrhoea and rectal prolapse. Histopathological changes In the liver were characterised by severe portal fibrosis with bile duct prollferatfon and mild portal round cell infiltration. The calves were fed a ration con­ taining locally·produced maize. The Implicated maize was Infested with Aspergillus f/ovus and contained aflatoxlns B 1 , B.iil' G.1 and G z with total aflatoxin levels as high as 11 790 ng g-1. This Is me first report of a field outbreak of bovine aflatoxlcosls In South Africa.