We received our Cornish Rock chicks about 2 weeks ago. This is our third time raising them. We have done nothing different. Same brooder, bedding, feed, water, lamp. We have had one chick die ever day or two. They all seem to be healthy and growing, then we will check on them and one has passed. We are feeding them medicated chick starter and putting chick vitamins in their water. Any ideas on what may be going wrong? And how I can stop it? And advise on if they would be ok to eat? I contacted the hatchery and they were no assistance. Thanks for any help.