My YO is having the spare field cut for hay for my 2 horses fo winter, so the other day we went round and DE-Ragworted it. and took out some docks too, i wasn't sure on the danger when it was in hay so we took it all out, glad i did now!!
Ragwort is highly poisonous - it does not lose its toxicity when it is dried (i.e.) in hay. Horses tend to avoid it when it is growing as it has a pungent smell, however when it is dry in hay, it loses its smell and can easily be eaten. Ragwort poisoning is a horrible death - please pull it.