Hi. I added 6 hens to my flock today. They had pretty rough looking bare spots on their backs, from being picked on at their previous location. These chickens were given to me by a friend who is getting too many eggs. I just checked them, and my chickens seem to really be picking on them. Their backs are actually bloody. One of them has almost no tail feathers. Stupid question, but do tail and back feathers grow back?? What do I treat the wounds with?