I just discovered that the bag of chick starter that my chicks just finished may not have been medicated. The tag on the bag says, "Starter-Grower Crumbles with APEX. Is that medicated? The bag I bought today is a different brand, but it clearly says "medicated" on it. If the feed they've been on for the past 4 weeks wasn't medicated, is it okay to give them medicated now?