Chicken lays weird-shaped eggs. Wherefore??

[julskinka]

This link link might help.

Egg Quality Handbook

http://www.thepoultrysite.com/ourbooks/1/egg-quality-handbook/

I think you have two different things going on.

Some hens' bodies just don't process the calcium they eat to make the shell material. No matter how much they eat not enough gets processed. Some don't have the instinct to eat extra calcium when you offer it. While the calcium is there, she just may not be producing enough shell material.

The egg normally goes through a certain process in the shell gland. It normally takes an egg about 25 hours to go from the hen releasing the yolk to start the process until it is laid. Most of that time is in the shell gland where she is adding shell material. The last half hour is usually used for a brown egg laying hen to add the brown to the outside of the shell. It's possible something is wrong with her timing. With that bump and one end being thinner than the other, she may be starting the laying process and stopping it for a bit.

If it were a very rare occurrence, well we are all entitled to an occasional oops. It's no big deal. But yours is consistent so I think she has a problem with her shell gland. That's quite possibly genetic, I'd never try to hatch one of her eggs and risk introducing that more into my flock.

This is very helpful! Thanks!

 

[aart]

Some hens' bodies just don't process the calcium they eat to make the shell material. No matter how much they eat not enough gets processed. Some don't have the instinct to eat extra calcium when you offer it. While the calcium is there, she just may not be producing enough shell material.

This^^^
Have had several hens whose shell glands have gone wonky.
Have 2 SLW now that recently started laying eggs similar the one posted in OP.
...and they both definitely go for the oyster shells.