I am new to BYC and caring for chickens. I have 4 pullets 19 weeks EE and Speckled Sussex 16 week Barred Rock and Silver Lace. I was surprised this afternoon with an egg. It's small and light brown. The nesting boxes were closed so the egg was by the coop under a tree. I have no idea who laid the egg. I have all 4 of them on King starter that is GMO free. I live in Northern CA and need a suggestion for layer that is GMO free ( no corn no soy) preferably . My local feed doesn't have much variety. I figured that the extra protein the starter provides was good for them but now I realize that it may of spend up their development. Can I leave them on the starter and just provide oyster shells for calcium?