Chicks kept off the dirt and on wire will not guarantee them from getting cocci or worms. Cocci can be carried in the wind, on your clothing, on your hands, and even tracked from pen to pen on your shoes. It has even been known to be in the feed you buy. I have had many broody raised chicks that have thrived by having early and constant exposure on the ground and building resistance from day one. Although, you should keep a close eye on them just in case their system gets overloaded and need medicating.