Question about type of feed

[icsd71]

I have been using a feed brand called Country road Chick starter and grower 18% medicated. I use this for several weeks for the chicks then i go to a non medicated grower. My question is the medication in this type of feed is it harmful to me if I eat a meat bird raised on this or do i need several weeks of non medication before I butcher them? Also i cannot locate a web site for this food. Also who makes it? I think it is a branch of Cargill?