For you to consider: 3 sections, first section for cocks 9' wide 6' deep, middle section 4' wide 6' deep for hens, 3rd section 5' wide 8' deep for young (giving the loft a L shape)
I am under the impression that the fast twitch muscle (used in quick bursts of energy) was fed in the main by carbs, after 40-60 mins of flight fats and protein then come into play.