Medicated feed is to prevent cocci from killing the chicks. It shouldn't be fed to layers and no chicken needs it after 8-12 weeks of age if you do use it. Most of us don't have cocci problems so don't even use medicated then all birds can be on same feed.Question from a newbie... when you say 'medicated' are you referring to feed with probiotics & electrolytes, or something more?
Thanks!