As the nation celebrated eggs, have you ever wondered why chicken eggs can be different colors? Most eggs are white or brown, but they also come in other colors, such as cream, pink, blue, and green, and some are speckled.
Nature has provided chickens with diverse color patterns for their feathers, skin patches, and eggshells for various purposes, including camouflage to protect them from predators and denote individual identity.
The color of an egg is primarily determined by the chicken’s genetics, said Gregory Archer, Texas A&M AgriLife Extension Service poultry specialist in the Texas A&M Department of Poultry Science, Bryan-College Station. That means the breed of hen will usually indicate what egg color will be produced.
For example, Leghorn chickens lay white eggs, Orpington’s lay brown eggs and Ameraucana chickens lay blue eggs. And the “olive egger” breed lays … wait for it … olive-green eggs.
But appearances aside, all chicken eggs have no major differences in taste or nutritional composition, Archer said.
Earlobes predictors
A good way to guess what color eggs a chicken will lay is to have a gander at the hen’s ear lobes.
“Generally, hens with white earlobes will produce white eggs,” Archer said. “But all eggs start white because the shells are made from calcium carbonate. They get their color from the hen’s genetics as the egg forms.”
He said chickens with lighter earlobes often have white feathers and produce white eggs. Those with colored feathers and darker earlobes will likely produce colored eggs.
Adding a little color
Nature has its own way of coloring eggs, and it doesn’t require food coloring or a paintbrush. Different eggshell colors come from pigments deposited onto the shell as the egg forms in the hen’s oviduct. The oviduct is a tube-like organ found along the hen’s backbone between the ovary and the tail.
A chicken yolk, or ovum, forms in the hen’s ovaries. A fully formed ovum leaves the ovary and makes its way into the oviduct. It then goes through a five-stage process to help ensure the yolk makes it safely to the outside world. The entire egg-forming process usually takes a little more than 24 hours.
It’s during the fourth stage of this process, which involves the shell gland, that pigments are deposited onto the shell, producing its color. So, in short, different breeds of chicken deposit different pigments on the shell as it forms, changing its exterior — and sometimes also its interior — shell color.
Archer added that shell pigment also has anti-microbial properties that may help reduce the risk of embryonic mortality. See more.
Source: Online/GFMM
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