I will likely run out of chick starter in a week or so; I got 5# from the hatchery my chicks are from, but I figured I'd go to a local feed store to pick up more. However, I don't know if they carry the same brand. Will it hurt the chicks to change to a different starter? What if they only have "start and grow" feed as opposed to plain starter feed?
Start and grow will be fine. That's all I use from day 1 till week 16 or so. If your current feed is medicated, see if you can't get matching medicated feed with the same drugs in it. Medication is for the protection of cocci as a thiamine blocker.
What ever you get, starter or starter grower, it is always recommended to blend some of the new feed in with the current feed to start with, rather than an abrupt diet change.