LUPINOSIS: RESPONSE OF SHEEP TO DIFFERENT DOSES OF PHOMOPSIN

Summary Phomopsin, the mycotoxin produced by Phomopsis leptostromiformis , was found to have a very high toxicity for sheep. When administered as a single, subcutaneous injection over the dose range 1·25 to 98 μg/kg body weight, all sheep given 37·5 μg/kg or more died. Some, though not all, died following lower doses, the minimum lethal dose being 10 μg/kg. The time course of hepatic response over 21 days after phomopsin administration was followed by plasma biochemical analyses including those for some enzymes (glutamate dehydrogenase, γ‐glutamyl transpeptidase, aspartate aminotransferase and alkaline phosphatase), total bilirubin and the determination of bromosulphophthalein clearance rates. Hepatobiliary impairment was apparent after all dosages of 2·5 μg/kg and above while 1·25 μg/kg approximated the ‘no effect’ level.