Worried about too much calcium

I'll be interested in the other responses to this too.  I've always heard not to feed the layer feed until they are laying so you are perhaps right to be concerned.  I have a mixed-age flock, so plan to leave them on Flock Raiser, supplemented with Oyster Shell until the youngest is laying, just to be on the safe side.

Some poultry scientists actually recommend switching to the higher calcium layer feed a couple of weeks before the onset of laying. But, I probably shouldn't say that here since so often we are tempted to think that layer feed "makes" them lay. Perhaps, we can feed it to nonlaying pullets and there will be a benefit. There is probably very little difference between layer feed and pullet developer feed, except for the percentage of calcium. Layer feed won't make them lay.

Note the "developer," "pre-layer," and the "5% to 50% production" feed calcium levels in Table 1, Feeding the Commercial Egg-Type Replacement Pullet. You probably can't go by that "15 weeks," however. These are production pullets and geared up to kick into production pretty much all at once and early compared to dual-purpose birds.

The calcium in the feed is used by the laying hen to produce eggshells. At about 18 or 20 weeks of age, the pullet is probably storing a good deal of the excess calcium in the medullary bone and other bones of her skeleton. She no longer has developing kidneys and can probably void any extra that isn't stored or used for eggshell production.

I wouldn't worry much about it unless the wait for eggs runs on for months and months.

. . . just my 2¢

Steve