Why are chickens born yellow?

Chickens are born yellow because of a pigment called protoporphyrin IX that is found in the blood of developing embryos. This pigment is produced in the liver of the embryo and is then transported to the developing feathers. The pigment is yellow in color and is what gives chickens their characteristic yellow color.

The reason why protoporphyrin IX is present in the blood of developing embryos is due to the presence of hemoglobin. Hemoglobin is a protein found in red blood cells that carries oxygen from the lungs to the rest of the body. During the development of the embryo, hemoglobin is broken down into its component parts, one of which is protoporphyrin IX. This pigment is then transported to the developing feathers, where it gives the chicken its yellow color.

The yellow color of chickens is also affected by the presence of other pigments in the feathers. As the chicken matures, other pigments such as carotenoids and melanins are produced and deposited in the feathers, which can give the chicken a different color such as brown, black, or white.

In summary, chickens are born yellow because of the presence of protoporphyrin IX in the blood of developing embryos. This pigment is produced in the liver of the embryo and is then transported to the developing feathers, where it gives the chicken its characteristic yellow color. The color of the chicken can be further modified by the presence of other pigments in the feathers, such as carotenoids and melanins.