I have a mixed flock (one RSL hen, one EE hen, 1 maran pullet, 1 silkie pullet, and 1 cochin pullet). I have been feeding them layer crumbles. I was reluctant to switch to another type of feed because the EE's eggs have VERY thin shells. (Already tried just about everything I could think of for that). Anyway, the EE is molting and not laying now anyway. (She can either get her act together in the spring or she's gonna go in the stew pot). The RSL's egg shells are like rocks, so I'm guessing she doesn't need the extra calcium. And I've learned that the extra calcium is bad for the pullets. The other factor in this is that the pullets seems to be maturing VERY SLOWLY. I've owned them for 3 months and that would make the youngest of them 20 weeks and still no real combs or wattles. (Maybe this is normal?) Anyway- this question is getting confusing!- should I switch them to something with higher protein to get them to develop faster? Or flock raiser? Or what? Oh- and they do have oyster shells available in a side dish and I occasionally feed egg shells back to them.