Chickens don't really seem to like the oats, so if you add them to the mix, go easy and test the waters first. Barley is cheaper and has more protein and they seem to love it fine. Wheat is hard to soak along with other grains because it's so darn hard but it wouldn't hurt to add it in moderation. I'd buy small amounts first and see what works with your flock before stocking up in bulk.