How long does mating take to be effective?

[I hate plucking]

Hi

We have 1 muscovy drake with 3 muscovy hens. They've been together for 4 weeks. We've only seen him mating one of them. He seems fairly mature. Pretty large carnuncle.
How long do we need to let them mate before we can expect the eggs to be fertile? Right now we're collecting the eggs and selling them.

Thanks
Dave

 

[sourland]

If he has been with the hens for 4 weeks, the eggs should be fertile assuming that he is mating all of the hens. Actually, they were probably fertile within 3 days of the first time that he bred them.

 

[I hate plucking]

Thanks Broody
I recently noticed 2 of the hens have small bald spots on the backs of their heads. I'm hopeful that's from him and not the chickens establishng pecking order.
We've still only seen him mating them once. Maybe he's shy .
I guess we can try letting them keep their eggs. Hopefully the worst of winter is over and the eggs don't freeze...
Dave