Some folks leave lights on 24 hours a day for faster growing. So far with my Cornish X I have them in a open hutch under the trees (6 birds) fed medicated crumbles for 3 weeks and that 4th week mixing medicated with plain crumbles. Now I have cal-grow (?) pellets for the last 2 weeks. The birds look about 6-7 lbs each at this point (Alive).
They are able to jump, run and no sweating or turning blue from heart problems. I will put the light on 24 hours for the last 8 days to let them gain fat or meat.
I do have one x that is really small, she is about 3 or 4 lbs alive.
I chose the foods that I did so there was no animal byproducts in them. Broiler feed often has ground feathers and chicken parts in it. I say no!!!!!!!!!! ewwwww. I want plant proteins instead- for example grass is a high protein food, so isn't lentals, soy and other grains.
Good luck on either direction you go, I can't wait to try one of these buggers!
Good luck, keep us posted on what you decide to do. ~kel