Chickens are extremely tough. The neck particularly so. When I am processing them I find it incredibly difficult to remove the neck from the carcass even using a really sharp knife or secateurs. So I am very doubtful they would have broken necks. My guess would be wry neck possibly from Marek's Disease, triggered by stress from over crowding, but birds usually thrash about and contort as they are dying, so it may just be that causing them to end up with heads twisted.
Some state facilities charge for necropsies, others provide a free service. The carcass needs to be refrigerated on the day of death and sent off in appropriate packaging. There is a thread here on BYC which tells you how to do it. I will see if I can find it.
Some state facilities charge for necropsies, others provide a free service. The carcass needs to be refrigerated on the day of death and sent off in appropriate packaging. There is a thread here on BYC which tells you how to do it. I will see if I can find it.