You may have noticed that chicken eggs shells come in different colors. Some people believe that brown-colored eggs are more nutritious than white-shelled eggs. Is this true?
The eggshell is rich in calcium carbonate and acts as a chamber for the development of the embryo. Although many people believe that their color is related to the animal’s diet, this is not quite true.
The pigments that color the shells, hemoglobin or bilirubin, are present on the walls of the oviduct. The color of the shell, which can be white, brown, red, green and even blue, is related to the breed of the hen. Mediterranean chickens, like the Leghorn chicken lay white eggs. American and Asian chickens, like the New Hampshire chicken, lay eggs in shades of brown. A study published in 2020 indicates that the color of the egg shell is genetically determined.
Many people say that the color of the feathers determined the color of a hen’s egg shells. However, sometimes there are white animals with dark colored eggs and vice versa. It is worth noting that some breeds of chicken are able to lay eggs with different shell colors. In fact, the hen’s diet has little to do with the color of eggs it lays.
Some people claim that by looking at the chickens’ ear, it is possible to determine its eggshell color. Chickens with a white disc lay white eggs, and those with a reddish ear disc lay red-shelled eggs. However, this rule is not always valid.
Are Dark Shell Eggs Healthier Than White?
It is important to note that, regardless of the color of the shell, eggs have basically the same nutritional value. Therefore, there is no difference in the acquisition of one or other egg color, only with regard to price.
Unlike the color of the shell, the color of the yolk is directly related to the hen’s food. Chickens that eat more corn, for example, have eggs with a reddish yolk. This is due to depositions of carotenoids (reddish-colored pigments) from the food eaten.
It is for this reason that the egg yolks of free-range chickens are more orange than those of chickens raised indoors. Free-range chickens are normally fed with foods that contain more nutrients, and pigments which color their yolks in dark orange.