rooster mates with hen. fertilized when?

[equinelyn]

After a rooster mates with a hen, will the egg she lays the next day be fertilized?
When you have one roo and many hens how do you know what eggs to collect if you want to incubate them?

 

[Judy]

No. The egg is fertilized in the ovary then finishes forming as it passes down to be laid. I believe it is about 3 days. As for which eggs: you take your chances!

You can tell whether an egg is fertile after you crack it: https://www.backyardchickens.com/forum/viewtopic.php?id=16008 (from the sticky in the Incubating and Hatching forum.) Of course you can also incubate it and see if it develops. There's no way to tell after it is laid without cracking or incubating it.