In years when the weather will not cooperate for hay making, it is common for farmers to use preservatives to help prevent mold formation in hay.
Researchers have found that when given a choice, horses preferred hay that was not treated with a preservative over hay that had been treated with a preservative. However, horses will readily consume treated hay when a choice is not given.
Yearlings receiving hay treated with a preservative consumed and gained just as much over the trial period as yearlings consuming untreated hay. Clinical measures of well‐being were not affected by consumption of preservative‐treated hay, indicating the preservative had no negative effects on the horses.
Therefore, feeding horses hay treated with preservatives is a safe and common practice, especially in years when poor weather conditions exist for making hay.
For more horse information visit the University of Minnesota Extension website.