When do I switch to a diiferent feed from starter?

If a seperate grower (which is usually not medicated) is available, you could switch them now.
If all that is available is a combination starter/grower they can stay on that until 18 to 20 weeks, or you get your first egg; whichever comes first.

 

It's fun on this site!

 

I switch mine from medicated starter to a all-in-one at around 10 weeks old...it is a little lower protein and beefed up on the other good stuff...then when they begin laying they go on a layer with oyster shell - free choice to them.

 

You could change from starter to grower right now if you want. I'd mix the starter and grower about 50/50 until the starter is gone.

Or if you like you could just keep them on starter until they lay the first egg then transition them over to layer, again mixing 50/50 until the starter is gone.

I've done it both ways and could not tell any particular difference.

.....Alan.