I am going to build a Turkey enclosure,semi open air with roosts and a nesting box with a small run (26x8). My Turkeys will free range with the chickens everyday. I just need to get them out of the chicken run. They're too big and need to get their own place. I'm not to concerned about Blackhead. It stays really dry here in Central Texas and I rake the run out pretty often to keep the droppings at a minimum. The only time they are really together in the run is when they are waiting for me to let them out in the morning and the turkeys prefer to roost outside in the run, not in the coop with the chickens. Keep it clean and dry and I don't think blackhead has a chance.