Grow Your Own Poultry Feed
Here is an article on feeding chickens without using commercial feeds..... I got through the first 2 pages and stopped, because I do not have the time to work a full time job and do all of the things listed in the article for feeding a small flock of birds. So I use commercial feeds for my flock of @ 40 layers. They have the run of a 5 acre electric fenced pasture, and lay gorgeous brown eggs that have a golden thick yoke.
Bagged feeds use corn and soy because they are cheap and plentiful.