Glycogen storage disease type X caused by ochratoxin A in broiler chickens.

Day-old broiler chickens fed graded concentrations of ochratoxin A (0, .5, 1.0, 2.0, 4.0, and 8.0 micrograms/g of diet) for 3 weeks were examined histopathologically for glycogen accumulation in muscle tissue using both formalin and ethanol fixatives with periodic acid-Schiff stain in a duplicate diastatic slide technique. However, glycogen could not be visualized in chicken muscle by these techniques which work with human muscle. Quantitative analysis for the glycogen itself permitted demonstration of a significant (P less than .05) fourfold increase in birds fed 8 micrograms/g. Using startled birds demonstrated that this accumulated glycogen was about 99% physiologically available. These findings coupled with prior reports permit the assignment on morphologic criteria of the hyperglycogenation of ochratoxicosis as a type X glycogen storage disease.