I ran out of chick starter on Sunday. I thought I had two bags and forgot that I had gone through the second bag already. Something to remember when raising chicks: every time you fill their feeder they will empty it in half the time it took them to empty it last time. They grow exponentially for the first few weeks.
The co-op where we usually get our feed is closed on Sundays and when I go to the other, closer, non-cooperative one I feel like I’m cheating on our regular place. So I needed to find something else to feed them until I can get them the right stuff.
Chicks cannot eat “grown-up” chicken food. Not layer ration, at least. If I had some Flock Raiser® laying around from raising meat birds I could have thrown that at them, but layer ration has an extremely high level of calcium — high enough to damage the chicks’ kidneys and bone formation at this stage in their development.
So I nipped outside and pulled the nutritional analysis tag off of one of our bags of pig feed and compared it to the nutritional analysis on the back of the chick starter bag. Close enough for rock and roll, I say. Plus, they seem to dig it. So far no one is pooping funny or acting odd.
If you find yourself in a similar situation and you don’t have pig food laying around — and, really, who else does? — you can substitute a 50/50 mix of cornmeal and oatmeal. 
 Damerow, Gail. Storey’s Guide to Raising Chickens. © 2010, 1995, the author. Storey Publishing.