Det kan tydligen bero på hur gamla äggen är.
Q: I've been noticing that in some of our eggs, the yolk will have settled to one side. What could be causing this?
A: Of course, we can't know for sure what may be going on, but we can offer some information that may assist you in figuring it out!
First of all, it's important to understand what it is that causes egg yolks to stay centered in the first place. The chalazae are the parts of the egg that are sort of like springs, and they act to hold the yolk in place. The chalazae are the think whitish parts you will have seen on either side of the yolk. Sometimes people will choose to remove this part of the egg when cooking, since it is thicker than the rest of the egg, and if you are making a custard or pudding it can sometimes make a difference. (I never bother!) But as an egg gets older, the chalaza (singluar - chalaza; plural - chalazae) can unwind a bit, and this can cause the yolk to settle to one side or another. If you are using older eggs than you normally do (for instance, if you saved some up to use during slow winter laying), it is possible you're just seeing the natural changes that occur to eggs as they age.
The other thing that helps a bit keep the yolk centered is the thickness of the egg white. Younger hens have eggs with thicker whites, so as a hen ages, there may be some changes in her egg quality that could cause a yolk to settle to one side. In addition, hens sometimes lay eggs with watery whites in very hot weather due to the change in the way they breathe (to cool themselves down). That will not be an issue for you if it is not hot outside. But it's true, too, that some respiratory illnesses such as infectious bronchitis can cause a hen to lay eggs with watery whites (thus causing a yolk to settle). If you think that is the issue, you will want to contact a vet or an extension agent to get a diagnosis. We are not vets and can't diagnose your birds. However, if respiratory illness were an issue, you would probably see nasal discharge and see coughing or sneezing.
Aside from the concern of illness, there are two main occasions where a yolk being uncentered might be a problem. One is when making devilled eggs! It's a pain in the neck to have the white too thin when you're making devilled eggs, as it's so easy to tear the white or just have it collapse. And peeling can be especially difficult when the whites are thin on one side, too. The second is when incubating, since it can cause some problems for the developing chicks.