A half century ago when I was a teenager, my Dad had some sixty chickens which were kept in a fenced area of the barn. The floor was dirt, and the covering was pine shavings/sawdust.
This is the covering of choice in the south, since there is plenty of this stuff around, and it is what I will use in my run (nearing completion). The only problem back then was that every quarter or so,
it would have to be scooped out, and being the teenager, I was the one that had to do it. There is nothing that will make a hot August day more memorial that loading a couple of tons of chicken
manure. The ammonia keeps you from passing out.