What are your sources for pigeon feed?
Your local feed store - check if they will stock what you need.
Vendors by mail (in alphabetical order):
Baden Feed: http://badenfeed.com/
Des Moines: https://desmoinesfeed.com/pigeon-feed/
Foys Pet Supplies: https://foyspetsupplies.com/
Siegel Pigeons: https://www.siegelpigeons.com/
These are just a few, but by no means all. Check with area members to see what they use.