From what I read, it's coccidiosis that the medicated food protects against. Anyone more experienced than me chiming in would probably be helpful since i can't find the post. I'm sure there are people that do non-medicated from the beginning and have healthy flocks too. I think it's a personal preference with experienced chicken owners and a very stressful decision for us newbies.
That's why I followed the advice that I quoted before since my hubby had picked up the medicated anyway. I can assure you that I have 8 healthy free ranging chicks by following that advice.

That's why I followed the advice that I quoted before since my hubby had picked up the medicated anyway. I can assure you that I have 8 healthy free ranging chicks by following that advice.