Abstract
Eight Japanese Black breeding cows in a farm holding 120 cows showed anorexia, discouragement, swelled pastern and lameness within a few days after changing roughage to tall fescue straw imported from the United States. One cow of the five severely affected animals the hoof capsule of its right hind leg. The suspected straw contained 1,200μg/kg ergovaline, while the level of lolitrem B was below the detection limit (50μg/kg). Nitrate nitrogen concentration of the straw was 630 mg/kg. Anorexia and discouragement were also observed in the cattle at one of the eight farms using tall fescue straw from the same shipment. From these observations, we diagnosed this case as fescue foot, although experimental feeding of the suspected straw to Japanese Black cows failed to reproduce clinical signs observed in the field case.
