Experimental ochratoxicosis A in chickens. Histopathological and histochemical study.

Twenty-day administration of ochratoxin A (OA) at a dose of 1 mg/kg b.w. to one-day-old male chickens caused degenerative lesions in the epithelial cells of renal tubules and an advanced atrophy of bursal follicles which led to a marked reduction in the size of both bursal plicae and the whole organ. Moreover, a decrease in alkaline phosphatase activity in the brush border and an increase in acid phosphatase activity in the cytoplasm of the epithelial cells of renal tubules were found histochemically. An increase in acid phosphatase reaction in the cytoplasm of liver cells and in the hepatic intracellular spaces along with glycogen degeneration of hepatocytes was observed. However, a long-term (20 weeks) administration of 0.2 mg of OA/kg in feed caused no histopathological lesions indicating mycotoxin intoxication. In addition, no detectable (> 0.0005 mg/kg) ochratoxin residues were found in the kidneys, liver, and thigh and pectoral muscles.