I have two batches of broilers right now: One is three weeks old and one is five weeks old. Both batches have roughly 43-45 birds (I ordered 50 for each batch and I know how many I lost, but I didn't have the presence of mind to count when I got the chicks to see how many extras they sent me and they're really hard to count when they're moving around . So the older ones are in a 10x10 tractor and the younger ones are in a 6x11 tractor (for now, I know that's too small for that many birds). I was planning on building a second tractor for the younger batch- I know they're fairly cheap and easy to build, as I build the first one for about $130. But if I don't have to spend that again that would be great, plus I hated how much time it took me to do (like 1.5 days, because of errors, pieces I wasn't able to get, trips for more supplies, etc) and any time I can avoid working with fencing, I avoid it. I've read of people doing 75 in a 12x10 tractor, so could I do 70 in a 10x10 and leave 20 in the smaller one? I am home all day most days, so moving the tractors twice a day (or more) would be no big deal for me. Or would it be too hard to integrate the younger chicks with the older? Has anyone ever done this before? Any advice would be great. I am willing to build the third tractor if I have to, but I hate to do it when I only have about 3 weeks that I really need it (I'm having the older batch processed at 7.5 weeks). Thanks in advance!