Yeah that happens alot here too. When I picked it up out of the field my self, I tried to get the middle of the field. I think you get the mixtures on the edges. That is if it's a good field to begin with.
It made me very nervous when I'd come across that white stuff in the bales. But I was "told" that when they looked like that it was OK to feed. It was explained that yeah the hay molded after being baled, but when it turns into that white powdery stuff, it is not "actively molding". It's only when hay is actively molding that it can cause problems for the horses. Once it's done molding and dies off, it's not as good a quality, but won't hurt.
I feed it, and never had a problem, but didn't like feeding it at all.
Becky
I wouldn't have bought that hay at all... Not sure I'd ever trust it wasn't still dangerous, or still molding, for that matter.
If we had a truck and flat trailer that could drive through and buy out of the fields, that'd be a good way to do it.... at least you know what the weather's been for the last week. I worry about hay that's been baled wet, both that it will mold... but also that it might spontaneously combust in my barn.
I walked into this lady's barn and took a big sniff... it smelled dry and clean, not like the pungent damp grass smell I've smelled before.