That's all I ever feed....if nothing else is available I'll make myself buy the pre-bagged commercial feeds but I hate feeding it to my chickens. Get a bag of fresh milled, farmer mixed feed and the leading brand of commercially marketed feed and open them side by side, look at the color, smell them, examine the grain pieces.....what you are seeing is the difference between a small, local mill and a huge, commercial mill, with the feed from the huge mill being stored for week/months in large storehouses, trucked around the nation in trucks and sitting in the storeroom of your local TSC until it finds itself in your coop. The commercial feed is grayish-tan, has little smell that has anything to do with grain and doesn't really resemble anything that has come from a whole grain in the past. It sort of looks like Grape Nuts Cereal....
...mystery meal in a bag.
OR you can go directly to the local mill, get the same percentages of nutrients but it will be fresh out of the mill, tied at the neck that day by good ol' minimum wage farm kids and hefted right into your truck. You open it up and it's golden, it smells like it was just harvested and most of the time it was and it was from a local harvest...it smells good enough for US to eat and the chickens show a distinct preference for the fresh milled grains. The older the grain, the sooner it loses nutrients...and all the more after it's been ground.
Which would you rather feed?