Chicken Egg Color Genetics Discussion

[ChickenCanoe]

I guess what I’m really asking is how they got the green egg to pass down from generation to generation.

That's because both parents have both blue and brown genes.
There are many more than one brown egg gene.

 

[Skipper81]

1 of my girls is black orpington Americana cross and she lays almost white eggs which is confusing because there all sisters

 

[Brahma Chicken5000]

That's because both parents have both blue and brown genes.
There are many more than one brown egg gene.

Ok. Well that makes sense. What letter is used to represent the brown egg gene?

 

[Brahma Chicken5000]

1 of my girls is black orpington Americana cross and she lays almost white eggs which is confusing because there all sisters View attachment 1268467

That is odd.

 

[Skipper81]

I don't have chicks yet they are on day 17 in the incubator

 

[Brahma Chicken5000]

I don't have chicks yet they are on day 17 in the incubator

Ok. I’d love to know what color eggs the pullets lay.

 

[ChickenCanoe]

Ok. Well that makes sense. What letter is used to represent the brown egg gene?

Not sure because as I said, it isn't a single gene.

 

[Brahma Chicken5000]

Not sure because as I said, it isn't a single gene.

Ok

 

[Skipper81]

Ok. I’d love to know what color eggs the pullets lay.

Yeah it's going to be interesting to find out
The orpington Americana mix has layed all winter for me I'm pretty suprised

 

[The Moonshiner]

Every egg starts as white. Then they have two genes either the blue egg gene or non blue egg gene. (We'll call non blue white for conversations sake)
Yes blue is dominate to white
Of course they can have one blue and one white or two blues or two whites.
The genes for brown is separate and yes involves several different genes all of which aren't know. The different brown genes are why there's such a variety of shades of brown.
Lets go back to white and blue. We'll call it step one. You know how it works. Each chicken has two genes and pass one of their two to their offspring.
Isbars are pure for blue eggs and pass blue egg genes to all their offspring. In step one they are just as ameraucana or legbars they breed true for blue.
Step two is brown egg genes. No there is no green egg gene. Its just a matter of having blue and brown genes in the same bird. Brown genes on white make brown. Brown on blue makes green.
Isbars also carry brown genes so they pass one of their two blue genes and their brown egg genes to their offspring. They breed true to green because they get blue and brown from both parents.
If you look at olive eggs you can see how they came about. To get olive eggs or green eggs you cross in brown egg genes into a bird with blue egg genes.
Brown egg layers have two white egg genes so when you bring in the brown you bring in white. The offspring then have one blue gene and one white egg gene then also brown egg genes. If you then cross those together you can get one blue gene and one white gene (50%) two white genes (25%) or two blue genes (25%) the brown genes or at least some of them are going along for the ride.
With isbars selective breeding resulted in getting two blue genes and brown genes in the same bird so unless you cross in white egg genes they have no choice but to breed true for blue and brown so results in green eggs.
That's what olive eggs strive for. Problem with them is that when selective breeding to get the two blue genes back together you lose some of the brown genes so the eggs result in lighter then olive green. Breeders then breed back to a dark brown layer to darken their green eggs. When doing that they bring back in a white egg gene and have to start over in trying to get pure for blue again.
Hope that makes sense.