This is the first time I've tried Cornish Xs, I just have 3 who are being raised with other standard breeds of the same age. They spend the day in a covered tractor, with Flock Raiser in their feeder. At nightfall they all pile in the corner of the tractor cheeping until I pick them up & put them in a wire cage for safety's sake overnight. No one has food or water from nightfall until about 8 AM when I let everyone back out of that cage. This batch of chicks is 7 weeks old. The Xs are big & beefy, stomping around the pen, laying in front of the feeder to eat, occasionally acting like real chickens taking dust baths & pecking at the grass. Sadly, this afternoon I found one of them laying dead in the pen. Nothing unusual with his appearance, crop not too full, nothing weird coming out any orifice. Even more sadly was the fact that I had to bury this bird instead of processing him. Though I found him right after he died, and he was still warm & pliable, I've been treating them with Sulmet & its instructions advise waiting 10 days after medicating before eating. I plan to process the other two birds ASAP, as soon as their withdrawal period is through. What else should I do to keep them going until it's their time? I have a little pen they can stay in by themselves, should I put them there & start giving them less feed? Poor things, I won't feel bad butchering them. They remind me of dinosaurs, waiting to go extinct. Plus, they're so hefty, I can't wait to get them in the oven. It was such a shame to have to bury all that good meat today. Thank you for your advice.