LIVER-DISEASE IN CATTLE INDUCED BY CONSUMPTION OF MOLDY HAY

Normally innocuous forages are sporadically associated with hepatogeno us photosensitization outbreaks at certain times of the year or when g rown and harvested during unusual environmental conditions, such as pe riods of excessive rainfall. Allegations of livestock illness followin g consumption of such moldy hays are associated with clinical syndrome s uncharacteristic of known forage-related diseases, suggesting that u n-identified toxin(s) may be repsonsible. This study was instigated by field observations of hepatogenous photo-sensitization In cattle fed alfalfa-grass forage. To document the toxic nature of the hay, large b ales of hay (450 kg) were fed, ad libitum, to 3 groups of 2 calves eac h. Elevated serum liver enzymes provided evidence of hepatobiliary dis ease. Gamma glutamyl transferase activities in serums of the calves su stained at least a 10-fold increase above baseline during the feeding trials. Histologic examination of liver biopsies and postmortem sectio ns revealed mild periportal fibrosis and biliary hyperplasia. Culture material from 12 fungal isolates from the hay failed to induce liver d isease in calves.