Medicated or not depends on different situations.
If you are having your peeps vaccinated for cocci from the hatchery then you should not use medicated feed.
If you aren't having them vaccinated from the hatchery, or hatching your own, then you should feed medicated feed for a healthy flock.
I would never take the chance of having cocci develop in the flock when you can take the necessary precautions for it not to happen.
I assure you, that if it developed within your flock, you would be sorry for not taking the correct actions.
The mild medication in the feed has no concern to humans, but everything to the flock that becomes infected.....then it will be stupid is as stupid does.
If you never had chickens, and they are in a new environment, you won't have the same problems as old ground, however building resistance within the flock should also be considered.
bigzio