Start mixing in layer feed?

[Peckasso]

I have 12 pullets that will be 18 weeks old in 2 days. The breeds are Australorp, Buff Orpington, Americana, and Wellsummer. I got my first egg 2 days ago from one of the Americanas and another egg today. Probably the same bird, but I'm not sure which one it is. Should I start mixing in layer feed for all of the girls, or would it be better to offer oyster shell free choice until all or most are laying? Thank you for your help!

 

[nuthatched]

What are they eating now? Yes, I'd start mixing in a higher protein layer sine they're not full grown yet

 

[Folly's place]

Add that separate dish of oyster shell, and consider staying with an unmedicated chick feed or an all flock feed, more in the 20% protein range. Most layer feeds are 16% protein, too low for growing birds, and for many birds generally.
Mary