From the "why not try it?" files, this one actually worked. After water got under the hay tarp (despite our heroic efforts to prevent it), several bales on the bottom were moldy and soiled. Out of necessity to assure NO risk to the horses, and a great dislike for WASTE, I took a chain saw and simply sawed off the bad end of the hay bales.
The moldy hay was hauled off and the SAFE usable hay went on to nourish deserving horses.
-- Shari Frederick, happyhorsehavenrescue.com