I double checked my info, because I really do Not raise many chickens. The numbers for Muscovy are a bit different.
Most chickens will be sitting by twelve days if they're going to. Some sit sooner. Some sit later.
You can safely wait fourteen days before putting the eggs into an incubator. If you wait till 21 days, then you won't have many hatch, if any at all. So fourteen days is the cutoff.
Hatcheries say that you start losing viability at day seven. Maybe so, but I've never seen it.
My ducks take up to twenty five days to lay all of their eggs in a nest (yep, some of my ducks lay almost thirty eggs to a nest). In those nests I'll notice that there's almost always a guaranteed fail of two or three. All of my ducks lay at least eight eggs. Almost all of them hatch one hundred percent. So, I'll agree with the twenty one day drop off, but not the seven day one.
I don't start having failed eggs until the nest is over twelve eggs. Every egg over twelve seems to slightly increase the chance that there will be a failed egg.
Then again, I've had bantam hens hatch out twenty two eggs and not a single one failed. She took twenty two days to lay them all, and not one failure.
Sooooo what I'm saying is: Go by the fourteen day cutoff until you can get a feel for your birds. If she looks like she's going to sit, you can wait a few more days, but do not let it get to 21 days.
(edit: also: if you want to guarantee that all of the eggs hatch with no chance of failure, then don't hesitate to take them in at day seven. But, if you want to try to let her go broody, you can. It's a small risk of one or two failed eggs if you wait and she doesn't go broody)
Most chickens will be sitting by twelve days if they're going to. Some sit sooner. Some sit later.
You can safely wait fourteen days before putting the eggs into an incubator. If you wait till 21 days, then you won't have many hatch, if any at all. So fourteen days is the cutoff.
Hatcheries say that you start losing viability at day seven. Maybe so, but I've never seen it.
My ducks take up to twenty five days to lay all of their eggs in a nest (yep, some of my ducks lay almost thirty eggs to a nest). In those nests I'll notice that there's almost always a guaranteed fail of two or three. All of my ducks lay at least eight eggs. Almost all of them hatch one hundred percent. So, I'll agree with the twenty one day drop off, but not the seven day one.
I don't start having failed eggs until the nest is over twelve eggs. Every egg over twelve seems to slightly increase the chance that there will be a failed egg.
Then again, I've had bantam hens hatch out twenty two eggs and not a single one failed. She took twenty two days to lay them all, and not one failure.
Sooooo what I'm saying is: Go by the fourteen day cutoff until you can get a feel for your birds. If she looks like she's going to sit, you can wait a few more days, but do not let it get to 21 days.
(edit: also: if you want to guarantee that all of the eggs hatch with no chance of failure, then don't hesitate to take them in at day seven. But, if you want to try to let her go broody, you can. It's a small risk of one or two failed eggs if you wait and she doesn't go broody)
