How old is too old?

[EggsnQuackers]

Breeders, at what age do you pull your drakes and hens from your breeding flock? I've got a wonderful Silver Appleyard drake but he's getting older. I'm concerned about his fertility this spring. One of my hens is getting up there as well and I know her egg production has dropped considerably since her first season.

 

[Amiga]

Good question. Is there a threshold parameter for percentage of viable eggs that makes the difference between pulling them or not?