There is provided a method of treating hay for preventing and/or reducing heat damage in high moisture hay and as well to preserve the same, the method including adding to hay a hay preservative including a hay preserving and heat reducing effective amount of at least one enzyme having a chitinase activity, either alone or in combination with a hay preserving and heat reducing effective amount of a yeast of the genus Pichia or a bacteria of the genus Pediococcus. There is also provided a method of treating hay for preventing and/or reducing heat damage in high moisture hay and as well to preserve the same, the method including adding to hay a hay preservative including a hay preserving and heat reducing effective amount of yeast of the genus Pichia.