No problem! And yes, many people do go a little lower on the protein at the end to fatten them up a bit. When I am using commercial feed and the main food source, I'll just supplement with cracked corn at the end. Scratch will do the same.
I'm probably going to make a post about the results of...
It's funny you ask this question right now. I am raising my current batch of Cornish X on non-commercial feed. I feed a variety of things, including cat food, beans, rice, a 5-grain scratch mix (that's the closest thing to commercial feed they are getting - it's a DuMor brand scratch), canned...