We bought two dozen meat chickens this year and all was well until we put the birds outside at about 5 weeks. A few birds at a time are dying off and it looks like we are going to lose them all eventually. It starts with the chicken appearing to get lame and their legs become completely stiff and do not appear to bend. They stop moving and cannot get to their food or water. After a few days they die. There are no other symptoms that we notice. We are feeding a Blue Seal chick grower and they have fresh water daily. A few years ago we had turkeys in that pen. Is that the problem? We also recently seeded the pen with grass. Is that an issue? Does anyone have any ideas before we lose all of the chicks?