I hatched Midget Whites froms sandspoultry April 3rd and the were VERY ready to eat by thanksgiving, even without free ranging. I had four hatch, two boys, two girls. I need all of them for my breeding program in '10 and I was REALLY fighting off the urge to eat one of the males... I would pick them up and just get hungry when I felt their meaty parts... Well, we have made it past the holidays and they are both alive still. Anyhow, not sure if that is the info you were looking for. I had some bourbon reds and they got the fowl pox and were run down by it and it slowed their growth quite a bit. They probably took a couple months more to mature. Again, probably not the info you were asking for, but it is relevant, because you could be planning on six months of growth but they could get sick and that will cause a delay in when they reach optimal weight.