For meaties you really need to go with lower protein. The problem is they gain weight too fast (muscle AND fat).. which puts a stress on their hearts and legs
Feeding too high protein content feed to meat birds can cause "flip".. which is preventable to an extent by lowering protein content to 18% (give or take a smidge).. some bloodlines can handle higher protein content (23-24%) better than others.. so it's always a good idea to limit protein to the "broiler" rations once the birds are at 3 pounds body weight .. most are formulated at 20% or less.. I think ours runs 16 or 18%
I find that very, very interesting. I swear each and every one of these studies says differently - but, they also stress the need for certain amino acids and minerals that are generally missing in most commercial starter feeds in the amounts required. Maybe that's part of it? Berry, berry interesting **makes notes and goes to dig around some more**