Hi John,

Propionic acid can prevent mold from forming. However, it doesn't remove mold that has already formed, and it is usually added to hay at baling. If the layer has thoroughly molded, replace it with a new sacrificial layer and compost the old one. If there is mold on only the part touching the ground, you could probably get more time out of it, but monitor it regularly to make sure the mold doesn't move up the to the new hay. 

Hi John,

Unfortunately, no, there are not any treatments that get rid of existing mold. If the mold is light and you are using the hay yourself, you could potentially spread it out well and give to beef cattle as long as you also make plenty of clean feed available (read more here: https://beef.unl.edu/beefwatch/2023/what-are-your-options-wet-hay/). Livestock are pretty good at picking through and eating non-moldy parts of the bale. However, do not feed moldy hay to horses or pregnant livestock.