Grass sickness is not down to eating grass, racehorses that are never on the stuff have died from it, laminites, causes, hard ground, foaling, clover, line breeding can be a factor. frost and a few more. Ragwort whatever you say is something not to be taken lightly and I for one prefer to be removing this plant from my fields that risk my animals. Farmers can have their payments taken off them until they deal with what is growing on their land. Fact. I asked the farmer who I buy my straw from .