I feed dry raw whole horse oats to the chickens daily, about a cup + for 7 birds, as a high-quality, high-protein alternative to scratch, at about $9-10 per 40 lb. bag. My chickens go crazy for oats. I presume that the oat hull is a healthy fiber, similar to what they might get if they were out foraging, eating grass seeds, beetles, the occasional baby mouse, etc.
The oats "appear" to have been digested well when they come out the other end.
The oats "appear" to have been digested well when they come out the other end.