We fed Buckeye feed right through Nationals, and had been using it for probably a year, and have since switched them. The only reason we changed is because Buckeye was so hard to find. Only one feed store several miles from us handled it. Now that we are in Texas, they look at us like huhhhh, when we try to find it. Never had any colic on it, and fed just what the directions called for. The amount is very small, as I remember, only 1/2 cup per feeding, and if you have trouble with their weight, (hard keeper) you could supplement it with a small amount of oats, is what we have been told. It does not have the starch in it that most feeds have, and therefore, no large bellies and thick necks. Oh yes, you are also supposed to feed hay with it for the added fiber.