Last year my husband (trying to be nice, bless his heart) came back from an auction with 10 bales of alfalfa for the goats. Unloading and stacking it, I realized it had all been baled wet and was beginning to mold. Being cheap...er frugal, I didn't want to toss it all. I spread the bales out (didn't open the bales) and sprinkled them liberally with DE, concentrating on those spots that looked either moldy or about to turn moldy. DE is an incredible drying agent (wonderful in pens for pee spots, by the way). It dried them nicely, arresting the mold development. Used all the hay!
Just a tip!
Just a tip!