In article ,
Charlie Pridham wrote:
Its ok so long as ragwort is growing as horses avoid it, the problems occur
when a field is made into hay as once dried they seem not to notice it. but
I would have thought it irresponsible to make hay from a field containing
ragwort (its not exactly difficult to spot) and its a lost cause down here
with so much mine waste land as well as the verges so it is just a waste of
time and money to remove it and the years when they used to try were just as
colourful as now when they don't!

Horses do indeed avoid eating live ragwort because the alkaloids
make it bitter, but they may start to eat small quantities if the
rest of the grazing is poor. They may even pick at it when there
is grass available - I have seen that happen. So horses shouldn't
be in fields containing ragwort (or vice versa), otherwise they
could become poisoned.

As you say, horses will eat hay containing dried ragwort. In all
the bales I've seen containing ragwort, it wasn't very obvious
because the dried weed was all green, probably because they were
all flowerless 1st year plants at the time of hay cutting.

Francis