My Guineas are 4 1/2 weeks old and have been in the same area of the barn since they were a few days old. I just put roosts in there last week and they love the roosts. How long do I still need to wait before they can go out and forage in my pasture? The barn room is 8' x 12' and the pasture is about an acre. I have 32 guineas. Thanks!