Question about a cracked egg

[Hestia]

Hello, I've just joined up but have been reading these threads for the past couple of weeks as I'm incubating eggs for the first time - this forum has been my go to for info since Google sent me here!
I have a question about a cracked egg.
I candled today (day 7) and took 2 eggs out of the incubator, one was definitely infertile but the other was really hard to tell, couldn't see veins but I could see a pretty big crack that wasn't visible without the torch, I also thought there was another air pocket at the end of the crack. Anyway (sorry long story) I decided it wasn't any good. My kids were helping/watching so we decided to crack them to see what was going on inside. Infertile one was exactly that but the cracked one that I hadn't seen anything in had a developing chick!
Obviously it's too late now but I was wondering if it ever happened again what the chances were of a cracked egg making it to hatch?
I'm going to be incubating more shipped eggs and am trying to get as much info as possible to get it right!
Thanks - sorry for a post of epic proportions!

 

[SilverBirds]

Depending on the severity of the crack, many people will seal it off with clear nail polish or wax. Most end up hatching without any issues.

Don't beat yourself about accidentally pulling a good egg. It's happened to the best of us. For the future, if you are ever a little uncertain if an egg is any good, leave it in the incubator just a few days longer. Or you can make a post with a picture here and ask for second opinions. Wishing you the best of luck with the rest of your hatch!

 

[Ridgerunner]

There are two main risks with a cracked egg. One is that the egg will lose excess moisture through the crack and lose so much the chick cannot hatch. The other is that the bloom is compromised. When the hen lays the egg it comes out wet. That wet layer that quickly dries is called bloom. Bloom is really good at keeping bacteria from going through the porous shell. If bacteria gets inside it can multiply and you get a horrible rotten egg that stinks and can contaminate other eggs.

As long as the crack isn't too bad sealing it with nail polish or wax usually works. But sniff the egg occasionally. If you notice a rotten egg smell, carefully dispose of that egg. Otherwise you should be OK.