I found this website in my research:
http://organicchickens.homestead.com/
There are some recipes for mixing your own feed in the Feeding Your Chickens section. There is also an associated yahoo group (links to the yahoo group are on the site). Some of those recipes don't have any soy or animal products.
The website owner seems to base their operation around this recipe & premise (the "quoted" portion is directly from the website)
"
*** It's not necessary to follow this recipe exactly... just make sure your birds are getting enough protein, which is predominant in the hard red wheat and the legumes. Free-range birds usually find plenty of protein from bugs, etc.
2 parts whole corn (in winter this is increased to 3 or 4 parts)
3 parts soft white wheat
3 parts hard red winter wheat
1 part hulled barley
1 part oat groats
1 part sunflower seeds (in winter this is increased to 2 parts)
1 part millet
1 part kamut
1 part amaranth seeds
1 part split peas
1 part lentils
1 part quinoa
1 part sesame seeds
1/2 part flax seeds
1/2 part kelp granules
free choice of granite grit
free choice of oyster shell
"
I'm going to continue to research it - I'm definately interested. I'm into "species appropriate diets", like grass for ruminants & raw meat diets for domestic carnivores like dogs & cats.