This was an interesting read (to me) so I figured I would share it. It was written in 2002 so I'm sure some of you have already read it, but I know others haven't.
http://ag.ansc.purdue.edu/poultry/multistate/Multi State Poultry.pdf
http://ag.ansc.purdue.edu/poultry/multistate/Multi State Poultry.pdf