how long before new rooster creates new babies

[entropy]

I am thinking of switching roosters in my pens....how long before I know for sure that the new rooster is the sire of the eggs? I guess I am asking how long hens can be fertile from a breeding?

 

[sumi]

Hens can produce fertile eggs for up to 2 weeks after getting serviced by a rooster.

 

[cochins1088]

I had wondered the same thing before and after some research, I decided you should wait a good 4 weeks. It probbaly depends on the hens, but I would definately wait longer than 2 weeks.