If you are worried about medicated, just check the label to make sure the medication is amprolium. It's actually vitamin based. It's not an antibiotic. It's to control cocidia, which can kill your ducklings really quickly with dehydration from diarrhea. So it is very worth it to me to play it safe and use the medicated feed especially for shipped birds. No matter how fast the shipping, the shipped ducklings have been stressed and that lowers their resistance.
Home raised ducklings, hatched and raised by their mother, get some immunity from the mother (by nibbling her poop).
Home raised ducklings, hatched and raised by their mother, get some immunity from the mother (by nibbling her poop).