i raise mine the exact same way , and when horse needs a stall i simply square off a corner with some chicken wire and then keep there food and water in there with short roost and i cut several small holes in the wire big enough for the chicks to crawl under with plenty of room , it helps the chicks get acclimated to the flock but still have a place to run and hide if they need to , dont add the holes until they have been in the new smaller cage in the coop for about a week so they no it is there home , i have also used the same method to feed chicks separate from the flock , i hope this helps