Do you all think it is OK to let the 12 weekers have access to laying rations now? I am adding the newbies hatched this fall in to the flock... was going to leave out the laying ration (purina Omega layena) in one feeder and flock raiser in the other... I do have oyster shells if needed for the older girls. Would it be better the switch them all to flock raiser? At what point can pullets tolerate higher calcium in the feed? Thanks!