For purebreed chicks, how many days with alone with rooster

[CynthiaM]

I have a friend that will be giving me hatching eggs of a particular pure breed. The rooster and hens are in with other breeds. I need to know exactly how many days the hens require isolation with the same breed rooster before the eggs will not be mixed breed eggs. I have heard varying days from 3 to 17 to 19, does anyone know for surely?

 

[Cloverleaf Farm]

At least 2 weeks, 3 to be certain.

 

[hinkjc]

I prefer 3 weeks, 4 to be certain. I actually checked eggs from separated hens to see how long it would take for the fertility to be lost after being separated from a roo and eggs were fertile for up to 3 weeks. At the 3rd week, it started dropping off.

 

[Krys109uk]

I agree with Jody about time hens remain fertile after being removed from the male. I've had similar results.
However if the male is seen doing his job with a particular hen the eggs ought to be fertile with his sperm as the eggs get fertilised by sperm from the most recent mating.