Marking the date of laying is not very important as long as you know the eggs are fresh. Old eggs are inferior hatching eggs.
If you give the hatching eggs all at the moment to the broody, the eggs all pip on the same day or one day /max 2 days later.
You can simply mark the hatching eggs with a circle or a cross . That way you can recognise new laid eggs you want to take away.
What I learned, mainly from experiences from other byc keepers who had broodies.
If eggs that donāt pip/hatch within 2 days after the first pip/hatch something was not okay. But its hard to tell what caused it. Probably the eggs:
- were not fertilised, or
- were too long too cold or
- had an embryo with a mistake
- had a chick that was too weak to pip/hatch
Other reasons:
- weather circumstances were real bad
- the broody had too many eggs