Q: I would like to start feeding my horses large round bales, but I have no idea how many bales to buy. I have two average sized horses who would have 24/7 access and the hay. The large round bales are four feet by five feet. How many should I buy?

A: An average size adult horse (1,000 pounds) will eat about 2.5% of his body weight each day or about 25 pounds. For two horses, that would be 50 pounds each day. If you feed large round bales from October through May (8 months or 240 days), you will need 12,000 pounds of hay for two horses. The average four feet by five feet grass large round bale should weigh 850 pounds. 12,00 pounds divided by 850 pounds equals 14 large round bales.

However, two horses might not eat the large round bale quickly enough and there will probably be some waste from rainfall/snow. It would be best to place the large round bale in a covered feeder or inside a lean?to to reduce waste from the environment when feeding only a few horses from a round bale. Ideally a large round bale would be consumed within seven days. This is usually achieved when four or more adult horses feed from a large round bale.

Also, we know that large round bale feeders can help reduce hay waste. Hay waste from large round bales feed in differed feeders ranged from 6-33% waste, while not using a feeder resulted in 57% waste. For more information on selecting a round bale feeder, see information from the University of Minnesota on our website. Considering waste associated with feeding large round bales, I would recommend buying 16 large round bales for your two adult horses for the winter months.