Medicated with what? All medicines are not the same. Aspirin and penicillin serve different purposes but they are both considered medicine.
After trying to emphasize the importance of knowing what you are talking about before making suggestions, I'll break that rule. The medication in the chick feed is probably Amprolium, Amprol, something along those lines. If it is something else, what I am about to say has absolutely no meaning in relation to that medicated feed. It may actually be counter productive.
Medicated feed containing an Amprolium-type medication is used to reduce the effects of coccidiosis, often called cocci. Cocci is caused by protazoa that live and multiply in the chickens gut. Wet chicken manure is also part of that protazoa's reproductive cycle. If it gets out of hand, cocci can be fatal. Bearing that in mind, I introduce the cocci protazoa to my chicks as early as I can.
There are several different strains of protazoa that can cause cocci. A chick can develop immunity to one strain, but that does not provide immunity to other strains. Chicks can better develop that immunity at a very early age. The older they are when they are introduced to cocci protazoa, the harder it can hit them.
The problem is not having some cocci protazoa. The problem is having too much. The cycle that usually gets people in trouble is that the protazoa in the chicks gut lays eggs which are passed out with its poop. If that poop stays wet, those eggs develop and the chicks eat them, where they hatch in the chicks guts. If the brooder is kept dry, this cycle is broken and the numbers usually do not build up enough to cause any damage. The dry brooder does not always work, but it usually does. But with a wet brooder, the numbers can build up to where they are fatal.
The amprolium in medicated feed does not kill the protazoa. It inhibits the reproduction to where the numbers don't build up to a dangerous level. It still allows some reproduction so the chick can develop immunity to that strain. Actually a totally dry brooder is not ideal from this aspect. The chick needs to go through a two to three week of this cycle to develop the immunity.
I don't use medicated feed. The way I handle it is to take some dirt from the run where the adults are and feed that to the chicks as soon as I figure they know what their regular feed is so I introduce whatever strain of cocci I have so they can develop that immunity. I put a piece of plywood in the brooder to allow the poop to build up a bit and stay damp. You don't want it wet, just damp, and you don't want a lot if it.
There is nothing wrong with feeding a feed medicated with amprolium. It is not an antibiotic. It does not build up in their system nor does it last that long in their system.
I'm sorry if I came across strong at the start, but if the "medicated" in the feed is an antibiotic, then all I said does not work. That would prevent them from developing the immunity they need and would put your chicks at risk.
Good luck!
