I've little idea what element of the crop gives me a problem, but I know for certain that something does; restricted breathing, running eyes and a blinding headache. Certain lilies do it too but I've never encountered them in whole-field quantities.

The cattle-feed explanation had not occurred to me, Megan, I believe that most livestock in that region are able to over-winter in the fields (it is pretty temperate) but it would still make sense to have at least some feed available.