I have heard that meat birds stink (well--their poop does), so I was planning on converting an old dog run into a chicken tractor. Do meat birds need to have an elevated, closed- in area? Do they need a roost? I'm thinking not, since they will be heavy. What all are must -haves for a chicken tractor for meat birds. Also, the kennel is 5'wide, 8' long and 6' high. How many birds can I fit in there? Thanks!