Egg collor genetics

[Jennsbirds]

Are certain egg colors on recessive genes and others on dominant genes? If breeds are mixed, which gene decides egg color? Do easter egger mixes ever lay colored eggs? I can't find much on mixing easter egger breeds with other breeds.

 

[Ridgerunner]

Eggshell color genetics come in two parts. First there is one certain gene that determines if the base color is blue or white. Remember, this gene comes in a gene pair. Blue is dominant, so if just one of these two genes is blue, the base color will be blue.

Brown or green is just brown with the base color. It helps some people to think of it as a blue or white car being spray painted with brown. There are a whole lot of genes that affect the shade of brown. That’s why you get so many different shades of brown or green. Which ones are present, which ones are dominant or recessive, and how they all come together determines the actual shade of brown or green. This might help.

Base blue + no brown = blue
Base blue + brown = green
Base white + no brown = white
Base white + brown = brown

Let’s use upper case “O” to represent the dominant blue gene and the lower case “o” to represent the recessive default white gene. This might help you understand what I’m going to say.

A rooster does not lay eggs. You cannot tell if he has any blue egg genes or not like you can with a hen that actually lays eggs. But even with a hen that lays a base blue egg, you can’t tell if she has one or two blue egg genes. If she has two blue egg genes, called pure for blue, she will give one blue gene to her offspring. If she has one blue and one white, she will randomly give one or the other to her offspring. Same with the rooster, you just are often not sure what roosters have when you are dealing with EE’s.

So if one parent is O,O and the other is O,o, half the offspring will be O,O and half will be O,o. All pullets from this match will lay base blue eggs.

If both parents are O,o, ¼ of the offspring will be O,O; ½ will be O,o; and ¼ will be o,o. The o,o’s will lay base white eggs. The others will lay base blue eggs.

If one parent is O,o and the other is o,o then half the chicks will have O,o and half will have o,o.

If both parents are o,o than all offspring will be o,o and you have lost the base blue gene.

Hopefully this answers your question. If not, let me know.

 

[Jennsbirds]

Ah, that takes me back to bio class. Cool stuff, punnet squares.

I had no idea colored eggs worked that way.

Do some easter egger breeds have Oo and some OO? Or are green eggs just from hbrids?

 

[Ridgerunner]

Easter eggers are not breeds. They are just birds that should have the blue egg gene. The original chickens with the blue egg gene originally came from Chile. They were not really a breed, just a barnyard mix of chickens that had the blue egg gene. After they came to this country, people created the Ameraucana and Araucana breeds from them. People in Europe created some different breeds of blue egg layers from those same barnyard-mix blue-egg-gene chickens.

You can create an EE by crossing any breed pure for the blue egg gene with any other chicken. A lot of hatcheries started their EE flocks by doing this. They really add to the confusion by still calling their chickens Americauna or Araucana even though they are not pure breeds at all. Some people even believe that all Easter Eggers came from these breeds, but it’s really the opposite.

As far as I know all recognized breeds anywhere of blue egg gene chickens only lay blue eggs. Once you get brown into the mix it is really hard to get back from green eggs to true blue. There are just so many different genes that contribute to brown it is hard to get them all out of the genetic mix. I know a lady that mixed a brown egg laying chicken into her blue egg laying flock to get certain color and pattern genetics for a project she is working on. Fifteen generations later she is pretty much back to blue eggs, but she still gets some green ones. It is really hard to get all those brown egg genes out especially when roosters don’t lay eggs to show what genetics they have.

The green egg has nothing to do with whether it is O,o or O,O. Either one will make a green egg if brown is present.

You can’t even get everyone to agree what an Easter Egger is. Some people like me believe an Easter Egger should have at least one copy of the blue egg gene. Some people consider any chicken that has hatched from an Easter Egger to be an Easter Egger, whether it inherited the blue egg gene or not.

 

[Jennsbirds]

Sorry, I meant the different easter egger breeds, not that they are one breed. My bad.

But that clears a lot up. Thanks.