Everyone has different ideas---but darkness wins the later young bird races as for feed light trapping mix on a morning breed and wean on a night but make sure you give them greens, on the dark till 21st lights on till 11 after that. Looking for full wing on last race ,dont skimp on food at end of season they have a full wing moult to get through.and stop lossing them by starting to train them,step them up steady.