When given free-choice hay, horses wearing blankets voluntarily ate less than unblanketed horses. | Photo: iStock

When it comes to the “hot” topic of blanketing, a metabolic balance is at play, according to results of a new study. Researchers led by Michelle DeBoer, PhD, an assistant professor at the University of Wisconsin in River Falls, found blanketed horses ate 8% less free-choice hay than their unblanketed peers while maintaining similar body conditions.

The Study: Free-Choice Hay and Blankets vs. No Blankets

DeBoer and her fellow researchers blanketed eight adult horses housed in a dry outdoor paddock in Wisconsin from December to January. Nearby in a second dry outdoor paddock, they left eight other adult horses, similar in breed, body weight, and body condition to the first eight, without blankets for the same time period. Each group of horses had access to identical bales of grass-legume hay, and they could eat as much as they wanted.

The researchers found that, on average, the horses’ weight and body condition remained similar between groups throughout the study. But when the scientists compared the weight of the hay bales in each group before and after the study, they noted the unblanketed animals had eaten more hay. Calculating a daily average per animal, they determined that the unblanketed horses consumed 2.51% of their body weight whereas the blanketed horses consumed 2.31% of their body weight—a drop of approximately 8% of total hay fed