This whole discussion has been SO extremely helpful to me! We've been debating this very thing at our house. We don't vaccinate but are purchasing birds which have been, wondered about mixed flock!
Also, we put dirt in our brooder. The first time usually around 3 weeks. I didn't know it was good for the birds. I do it because they like to play in it and it's so fun to watch them tear it, and the weeds, apart! The first clump is always approached so cautiously.... they sneak up on it. Then it's a free for all! Good times on my end.
We handle the cocci threat this way; I don't use medicated feed. We use Modesto Milling's Organic Chick Crumble. I do medicate the water with raw apple cider vinegar and Conklin's liquid dispersible FASTRACK probiotic
https://www.conklin.com/cart/itemDetail.cfm?pline=02&cline=05&parentSKU=036616. I'm a rep and even though we are new at chickens, we've used the Fastrack on many other animals. It's a favorite with dog breeders because it eliminates cocci in the puppies. I figure that if it works for dogs (and cows and horses and pigs...) it aught to work on chickens. Our entire flock gets Fastrack probiotic in their water on a regular basis.
The Mareks thing just scares me. We are getting some high-end birds and I don't want to have my whole flock wiped out. When reading about it, there is little common-sense approach. It's good to know that other people have made the choice not to vaccinate for Marek's and had good results.
ronott1 - Is there anything you do vaccinate for?
Thanks everybody!