You don't have to I guess, but for Buckeye breeders to have nice sized birds, that's what they like to start them on. Ours turned out fine without it however, but next year, we want to try and see how they will turn out. Our Buckeye chick that we let a broody hatched is already twice as wide as the other chicks, so it isn't beneficial, but it will probably make them grow faster, because of higher protein levels, like meat chickens. Sorry if I was a little vague, does that make more sense?
I never heard that about having to start Buckeyes on gamebird food, could you explain that please?