What would make a chicken lay an egg with deep groves in the shell?

[chickenwalker]

I have a small flock of 9 hens that are 43 weeks old. All of the girl have been good egg layers even in this cold Michigan weather. I have one Buff Orp that has started to lay eggs with well "marbled" groves throughout the shell - almost through the shell. These eggs have not been dropped nor cracked. I've seen a few of those since September.

Any ideas? I've been searching BYC and the Internet for help but I can't find anything that addresses this problem. Thanks.

I gathered the following 8 eggs tonight. See the bottom right egg.

Here is a close-up. There are cracks on all sides.

 

[Angiebubs]

How often do you collect your eggs? Could it be that it froze and caused the cracks? Or could it be that when sharing the nestboxes that someone else is sitting/stepping on it?

 

[chickenwalker]

I collect my eggs several times a day on most days - and did collect them 3 times on the two days that this happened. The only two eggs that I have had freeze were both laid outside in the pen and this is very different. The 9 girls share 3 nesting boxes but the two eggs that I've had like this have been from the same hen. It almost looks like the egg shells cracked on the way out but this is not the same as when the eggs are "dropped" and cracked in the nest. Any ideas or suggestions?

 

[Den in Penn]

It looks like it was cracked while the shell was forming, internally. It does happen from time to time when they a jostled or take a hard landing. Don't know why it would continue to happen in one hen.

 

[chickenwalker]

Thanks. That really does make sense. I'll watch to see if I notice anything unusual going on.

 

[lahowardjr]

I don't know whether to say "cool" or "odd". Interesting photo and a plausible reason for the cracks. They appear to have been "fused" back together inside the hen.

 

[SD Bird Lady]

Is she a low ranking hen or do you have a rough rooster?? I think Den in Penn has the bes explanation. Unless she had a bad fall and those 2 eggs happened to be in "development"

 

[chickenwalker]

No rooster. Sweetie is one of our friendliest hens and she is at the top of the pecking order. Today's egg has one small fused-crack (probably impossible to see in this picture) in the middle of a thicker, a bit darker middle band. I'm concerned that she may have an egg laying problem - but this egg is better than the last two.

 

[lambchicks]

I have some like that every couple of days, but on the pointed end of the egg. After reading Den in Penn's response I wonder if it is from them flying off the roost in the morning, casue sometimes they do sort of hit the ground.