Where did you hear this? Have you experienced losses yourself? Is it a particular medication? I don't think this is true. I feed purina medicated chick starter to turkey poults and know other people who do as well with fine results.
In my experience poults are just more fragile than chicks.
I like zekii's suggestion about the food.
I only read it, but I think in several different places. I'm just not sure where, I think one was the book "Not Just For Christmas", but I can't swear to it. Anyway, I just assumed it to be true and since the turklet starter I have available here is unmedicated I just use that. As I mentioned, if I DO need to medicate, I add it to the water.
As a side note though, (which will probably get me in hot water,) I also raise sheep. Occasionally there is a need to raise a lamb on a bottle with milk replacer. I drive the feed store guy nuts by making him order in special "lamb" milk replacer instead of just buying the universal stuff he keeps in stock that "...everyone else buys!" The problem is, it's not formulated for lambs who are copper-sensitive and the stuff contains copper. Copper builds up in a sheeps liver so given enough of the stuff could make them sick or potentially kill them. Sure, there are lots of shepherds that feed lambs universal milk replacer, and they will say "sometimes you just lose bottle lambs." Anyway, I'm just not always that comfortable with someone telling me something is O.K. until I check it out.
As always, it's just my 2 cents. Anybody can do what they want, but I still prefer to err on the side of caution.
~S~
(post-script) I just checked my reference. It is indeed in "Not Just For Christmas" by Janice Houghton-Wallace on paige 56 that she warns "Chick crumbs should certainly not be given as not only do they not contain sufficient protein but some formulations contain the coccidiostat salinomycin which could kill the poults." Since this is a British publication I have no way of knowing if that is the same medication they use here, perhaps not, but that is what I based my concern on.