In very cold weather, hay consumption can increase 30%. Feeding twice daily might mean the horses are without fiber for three or four hours which is painful. Chewing and eating wood supplies the fiber which helps the pain go away. Feed more hay. I'm feeding a round bale, over 5', for two horses which normally lasts them 2 weeks. A bale was set out last Sunday and again today as we've had a long stretch of nasty cold with no letup this coming week. Because they are getting enough fiber, they're not eating the barn.