how long are they

[trickys10]

I just got a new rooster for my Croad Langshan hens and I was wondering how long the eggs will be fertile from my old roo until my new fertile eggs from the rooster start. I only want to hatch chicks from my new roo

 

[cmfarm]

They can stay fertile anywhere from 1 to 4 weeks with a 2 week average.