I don't think it's that old. Here's the issue I have, you, and many others, keep perpetuating the myth that medicated starters are bad for waterfowl, yet not one of you can say what medications are bad, or why they are bad, nor can anyone find a properly published study that asks up your claim. People need to stop spreading misinformation.
It's not just people on this forum, Holderread says in that book, "I still recommend using nonmedicated feed when possible." However, he also understands not everyone can find nonmedicated feed in their area. So please don't make try to make it sound as if he is pro-medicated feed. He says it likely won't have negative side effects "if fed at the proper doses" and later goes on to talk about cutting store bought feed with oats because of the high amounts of protein among other things.
Will medicated feed harm your ducks? Most likely not. Is it the
best thing for them? No.