I have three 17 week old hens and I am about to run out of their organic starter feed. From what I've read, they could start laying anytime between three weeks and three months from now. I am assuming they may be a little delayed since it's winter. Temps are warm because we're in southern California, but days are short. So my question is whether it's ok to just move on to layer feed at this stage, or do I really need to wait until they start laying due to the extra calcium in the feed. Thanks for any ideas on this!