I actually grind wheat for my birds. I set my grinder for a medium grind that gives me a blend of cracked wheat and whole wheat flour that I mix with boiling water and a little corn meal and stir every couple minutes for about 10 minutes. It should be wet and soft when done. I then add whatever I have laying around into the mix. I add applesauce, bananas, raisins, yogurt or whatever else I can find. It's also a good way to feed back crushed egg shell or cooked eggs..
This is the grinder that I use. I can grind a pound of whole wheat or whole corn into flour in a few minutes and highly recommend it for the great price and nice construction.
I feed my hens scratch as a treat in the morning and it has lots of cracked corn in it but the above formula should work with corn as well...
Why do you crack wheat?? Chickens love it whole. Just curious. They can eat whole corn right off the cob also.