We have an itty-bitty egg operation, with just a few hundred hens on the farm. Still, over the course of the last year we gathered about 110,000 eggs by hand, so we get to see our fair share of eggs.
Most of the eggs just look like eggs. There are natural variations in size and shell color. Sometimes we’ll get one with a wrinkled shell or an egg with an especially round or pointy shape. Some hens are a little overzealous with the shell and add extra knobs of calcium. Maybe once or twice a week we find one with an unformed shell due to failure to coat the egg with sufficient calcium. Those are all the normal abnormals.
But every now and then we find an egg that makes us scratch our heads. Here’s an oddity I found recently. I’ve waited a few days to see if I’d have any other strange eggs like it, but it hasn’t repeated. This flock of hens is well behaved and they normally lay their eggs in the nest boxes, but I found this one on the ground in the wood chips.
Chicken eggs are formed on an assembly line as they pass from the ovary through the oviduct, starting with a yolk, then adding an albumen (the white) and a membrane, then they are covered with a shell, and finally they get a bloom (a thin waxy seal coating).
This egg apparently was partially in the oviduct and partially in the shell gland, as the shapes of both organs are still apparent. Perhaps there was a problem detaching from the ovary causing it to elongate. The fact that the egg was laid on the ground instead of in a nest box may indicate that the egg was in a normal transitional stage when an abnormally strong contraction pushed the egg out. I can only surmise this sequence; none of the hens are willing to fess up to claim it.