How to make fertilized eggs?

Hello,
Sorry if my english isn’t good, so I tried to add a recipe for a fertilized egg but when we drop it either he is invisible or he has 0/100 of life and the baby spawn level 1. I want to know if it possible to make an egg in a smithy (for example) and the baby don’t spawn level 1 and the egg has 100/100 of life.
Thanks if someone try to help me and thanks so much if someone find the solution to my problem.