A University of Minnesota study showed that round bale feeders, particularly cone feeders, dramatically reduce hay waste according to TheHorse.com.

The researchers, led by Krishona Martinson, PhD., examined three different feeders: the tombstone, the cone and the curtain. Tombstone feeders completely cover the lower half of the round bale and have tombstone-shaped projections covering the upper half; they are open on the top. Cone feeders contain the round bale entirely within the structure. Horses must reach through metal bars to access the hay. Curtain feeders operate on a rotation. They open and are accessible to horses for four hours and then close for two. 

They found that the tombstone feeder allowed 15 percent hay waste, the cone feeder allowed 8 percent, and the curtain feeder allowed 9 percent. Using no feeder resulted in a 38 percent hay loss.

Although the cone feeder and curtain feeder had similarly low results in hay waste, researchers didn’t recommend the curtain feeder as it may encourage mane rubbing.

The researchers also determined that owners would earn back the money used to purchase the feeders through more efficient hay use. They plan to test six more feeders this summer.