What causes hen eggs to turn green

Green chicken eggs

If white chickens lay white eggs and brown chickens lay brown eggs, what should the plumage of the green layers look like and why are there no black hens' eggs? So simply deducing the eggshell color from the plumage color does not work. But how does the chicken get its shell color? In fact, genes are the only ones responsible for the color of the eggs. However, there is also an optical feature that in many cases provides the correct indication of the shell color.

How does the color get to the egg?

The so-called shell gland in the hen's hens is responsible for coloring the eggs. It ensures that color pigments are stored in the calcareous shell, which previously accumulated as a breakdown product from blood or bile and were temporarily stored in the liver. If all the dyes come together, the egg color is brown. If the chicken lacks the gene responsible for color formation, it will lay white eggs.

Green chicken eggs are another variety found in nature. The blood pigment goes through a number of shades of color when it is broken down, from blue to green to yellow, before it is stored. While in the case of chickens that lay brown eggs this degradation continues to the end, in the case of green-laying chickens the degradation ends after the first stage. This is where the greenish dye is stored directly in the lime shell.

Eggshell color - a matter of genetics

Which of the three basic color genes (blue, brown or white) are present in the respective chicken is already genetically anchored. Since genes are difficult to look at, and many old chicken farmers can still tell which egg color a particular hen lays, there has to be another way.

In fact, there are no clairvoyant skills involved here! It is a very specific body characteristic that indicates with relative certainty whether a hen lays brown or white eggs. It is the ear discs that in most cases allow conclusions to be drawn about the eggshell color of the chickens. If the ear discs are red, the chicken lays brown eggs; if the ear discs are white, it lays white eggs. In the case of green-laying hens, the ear discs are also red!

Fun facts about green eggs

Breed green layers

If you want to breed green layers, you only need a green rooster. The green color gene dominates over the brown! The The hen's shell color is therefore irrelevant for the offspring. Both brown-laying and white-laying hens produce green-laying offspring when mated with a green-laying rooster.

Green eggs are healthier

Green chicken eggs are healthier because they are low in or cholesterol free. This claim is very persistent but is unfortunately not correct. The color of the shell has nothing to do with the “contents” of the egg, the bowl is only used as packaging.

Often the exact opposite of low cholesterol is the case with green chicken eggs, because the chicken breed known for its green eggs (Araucans) has a particularly large yolk. If you take a look at the composition of the egg and its ingredients, it quickly becomes clear that a large yolk also contains more cholesterol.

Green eggs are not that stable

In contrast to green and brown eggs, white eggs have a distinct disadvantage. They lack a bit of stability due to the lack of storage of the color pigments. White chicken eggs are therefore a little more sensitive to damage. Green chicken eggs, on the other hand, are just as stable as brown chicken eggs. With them, too, the color storage has contributed to making the eggshell (more) break-proof. That green chicken eggs break faster is another fallacy.