How long will a hen be fertile after separating from the rooster?

[jsin]

I recently separated all the roosters of a second breed that was among the hens. How long should I wait before incubating eggs to be sure that I get pure breed chicks?

 

[Granny Hatchet]

i have read that it takes 2 weeks

 

[Fred's Hens]

It is generally recommended that to be more sure, a hen holds sperm for 2 weeks, although some individual cases have shown even up to 4 weeks, but that is a bit more uncommon.

This fact generally governs how long a hen will be fertile after mating and how long you will need before introducing a new male for breeding. 3 weeks generally accepted as being plenty long enough.