Mycotoxicity of Aspergillus ochraceus to chicks.

Five isolates of Aspergillus ochraceus, obtained from peanuts, were grown separately on sterile, moist corn for 14 days and fed to 1-day-old Babcock B-300 cockerels to evaluate their toxic effects. Two isolates were highly toxic, causing death of all birds during the 1st week of the experiment. Two isolates were moderately toxic, causing severe growth suppression with some deaths occurring throughout the 3-week test period. One isolate had no apparent effect. When the two most toxic isolates (diets) were diluted, survival time increased but severe growth suppression was evident. Postmortem examinations revealed a few small hemorrhages in the proventriculi of birds which died between the 2nd and 5th days. Emaciation, dehydration, and dry, firm gizzard linings were observed throughout the experiment. Extensive hepatic injury consisting of either fatty changes or necrotic foci was the principal microscopic finding. Suppression of bone marrow activity and depletion of lymphoid elements in the spleen and bursa of Fabricius were also found. The severity of the histopathological changes was directly related to the concentration of ochratoxin A in the diets.