I have some laying right now that has gotten wet. What with temps in the 90's today and maybe some more tomorrow or so, with a little raking, we can get it dried. True, it won't be as good but as long as it is thorougly dried and does not mold, I will feed it. We took the chance to cut it as it was getting to the point where it was past it's prime anyway.
I will not feed any mold at all but if my hay gets a little dusty, I will take the time (and it is a pain) to dunk it in a tub of water for moment. I have a horse with COPD. We have her stabilized but it will not go away. We can only give her Purina Advantage which is basically beet pulp for a grain supplement. During our recent spring checkup, the vet advised us to put her on the Triple Crown Safe Starch Forage.
There is no market for her and we have to much heart to put her down and she does throw beautiful foals should we choose to breed her so we deal with the expense. But anyway, near as we can tell, it was from dusty hay during a shortage that she got the COPD.
It has been my experiance that some people panic with wet hay and try to get it in then the hay ends up heating up or molding or both. What irks me is when people lie or think they should still command a high price for garbage.
A little common sense applies. Around me, the windows have been pretty narrow and not the best. During the first window, the nights were too cool. One of my suppliers has a fine stand of orchard/alfalfa. I like to buy the first cutting because I don't need the latter.
He sold most of his to someone who took it for silage and only bailed a little for himself. The bails were moist enough that I realized that I better not stack it. I left it dry for another few weeks in the mow then stacked it and it's fine. Had I not done that, I would have had problems.
Lastly, our pasture is limited so we stable our horses one half of the day depending on the season. I give them the inevitable less apetizing hay when they first get stalled so they have all day to think about it.