If cannibalism should start--you must STOP it in it's early stages or your entire project will be for nothing. Birds released with critical feathers missing, especially the back and head feathers, will not get past the first hard rain, particularly if it is a cold rain. If the problem starts, darken the brooder area by covering windows and doors. Leave only enough light for the birds to find feeders and waters, but not necessarily each other. Try hanging full heads of lettuce with a spike driven thru the center tied to a rafter or something so it will swing freely thus attracting the chicks out of curiosity and they will enjoy eating the greenery. Perhaps they'll leave their neighbor alone then. Give them more room, even if you have to move half of them to another area.
If all this fails, and you will know within a day or two, then you must de-beak the birds. Each and every one of them must be de-beaked or it will do no good. This process is very critical, especially in view of the birds being groomed for release. This is true because the young birds will need a full beak for plucking and cracking weed seed and grains, also for catching insects. Here is how you do it: if you have access to an electric de-beaker, use that. If not, a heavy duty toenail clipper will work. Snip just enough of the top beak only, to the point of it turning pink. DO NOT cut it so severely that gross bleeding takes place. You may damage the nerve endings of the beak if too much is taken, to the point of it never growing back. In any event, have a cauterizing agent available, such as silver nitrate, to stop any bleeding that occurs. De-beaking young pheasants is an art; too little taken off will not deter the problem and, of course, too much will stunt the re-growth of the beak. Go slow until you get the hang of it. Catch them one at a time and as you finish one bird, put him in an area apart from the others left to do. This will ensure that you get them all done.
link
www.oakwoodgamefarm.com/pages/Tips-for-raising.html#Stop%20Cannibalism