Just because I like to overdo everything in my life, I've been mixing my own feeds, and have a soy free, corn free recipe that I use.
If you want the recipe, I'll post my google doc spreadsheet with varying ones.
What I recommend to anyone who is wanting to go this route is this: Sprout or Grow Fodder as supplementary greens when using these recipes, and give the girls at least 4 weeks to get "used" to this, during those 4 weeks, you may notice some drop in laying, and overall what could be perceived as "disturbing" changes, but this is simply them getting used to the new feed, some would probably recommend "tapering" them down to the new feed, but I never did, too much troubles!
;-)
Hope this helps those who are looking to feed soy free, corn free.
Oh, and I use Azure Standard to source some of my harder to find stuff because I like going organic, but I think you could get away with not going organic and saving a ton of money.
One final thing, I realize my spreadsheet isn't ideal in it's setup, and those prices are what I get locally, feel free to copy it and fill in your own values.
If you wanna leave comments, feel free, just add a sheet.
;-)
https://docs.google.com/spreadsheet/ccc?key=0Atd5YN3TZWuHdHdOWTBkSnNVWGFBdE1KUkcxTWFRZXc
I also supplement my base chicken feed recipes with fish meal to up the protein for the breeders.
I try to feed my breeders 24% - 26% protein.
Also, I feed free choice oyster shell, and kelp meal, and redmonds salt, sometimes, if I'm lazy, I just feed free choice premix, if your girls aren't as confined (mine are in a backyard, so they don't access to a ton of fresh stuff all the time) I don't think it'd be necessary, but I overdo stuff...
Cheers!
-KS