You may need to supplement protein in their diet to stop the picking/pecking. Here's a link for you to read if you wish:
http://www.mofga.org/Publications/M...r/Summer2003/Chickens/tabid/1481/Default.aspx
http://www.mofga.org/Publications/M...r/Summer2003/Chickens/tabid/1481/Default.aspx