I'm assuming you mean feed that was medicated with Amprolium or some similar product. There are different "medicated" feeds out there. It really helps to know which one you are talking about.
If it is Amprolium or a similar product, some manufacturers say there is no waiting period. Some authorities say there should be a 4 week waiting period. Even the experts don't agree. Just between you and me, I think some of the "experts" are getting confused between the relatively small dosage of amprolium in the medicated feed and the larger amount of amprolium in the medicine used to treat an outbreak. But I am no expert and it never pays to assume much, especialy when it comes to health.
If you look at some government sites, they say that Amprolium in the medicated feed has not been proven to cause a problem in the eggs. But other governnment sites say it has not been proven that it does not cause a problem either. I love government legalese double-speak.
I go by what a bird vet said. He did not think the low amount of amprolium in medicated feed was much of a threat because it does not pass through the chickens intestinal wall that easily. But in light of the controversy and differing opinions, he thought a one week wait was reasonable.
