Gail Damerow Discusses Eggshell Imperfections and Anomalies

Alarmed backyard chicken owners report all sorts of shell irregularities in the eggs their hens lay. Continuing our interview series with Gail Damerow, poultry expert and best-selling author, we ask her to discuss eggshell imperfections and anomalies. 

Why are we seeing so many irregularities? 

Chickens have always laid eggs with occasional irregularities. However, industrial egg producers remove eggs with shell imperfections before sending their eggs to market. And they remove from the production line any hen that frequently lays eggs with imperfect shells. Therefore, most people don’t know about shell irregularities until they get chickens of their own.

What causes eggshell imperfections and anomalies?

All sorts of things. Hens experience everyday upsets that can result in an occasional glitch in the system. Or, a hen may have a physically defective shell gland, in which case she will persistently lay eggs with defective shells.

Additionally, there’s always the possibility of an infection in the hen’s ovary or even a flock-wide disease. A fairly common disease that can result in nearly any kind of eggshell irregularity is infectious bronchitis, caused by a coronavirus. This respiratory disease can be hard to detect in mature chickens, except at night when they are on the roost and you can listen for coughing and sneezing.

However, a disease such as infectious bronchitis would cause flock-wide shell anomalies. But most shell irregularities are occasional occurrences that affect individual hens. And they are perfectly normal.

Like fairy eggs?

Precisely. Fairy eggs are small, round eggs that often appear at the beginning of hen’s laying cycle. They may also occur at the end of a cycle, when a hen is about to take time off from laying.

Sometimes a fairy egg contains no yolk. Or, instead of a yolk, it may contain a bit of tissue from the hen’s reproductive system. Nothing to worry about.