The worst thing (to me) that can happen with my incubating eggs is that only 2-3 hatch. I had the thought that if that is the way it turns out I may go to the local feed store and buy some chicks to raise with them. I figure if I'm going to be taking care of any I may as well be tending to at least 12-15. The lady at the feed store told me that they will be getting chicks every two weeks starting March 9. Would it be better to let the (as yet unhatched) biddies grow a few days before buying any more? If the chicks at the store are a week or ten days old should I wait for some "new" chicks?
Seems like I've read this usually goes well for the first two weeks, maybe a little longer. I once added chicks to a broody / mama that were about a week apart without a problem.
I think it is possible my friend adds chicks od all ages all the time. I done know how but it works she has all sizes ages and kinds 34 roo and 60 hens 20 guines they all love each other more on the way..
I think as long as there is enough space, you should be able to add all ages together all the time. Just be vigilant with the newcomers. Young males do not seem to be a problem, just the older rooster can be a problem.