True or False? Olive egg genetics.

[TheOddOneOut]

Some other chicken keepers told me something interesting. I wasn’t sure if it was true or just something they had been told, but...
Anyways, this is the basis of it:
When you cross a blue layer with a brown layer, you get green eggs. And if you breed a f1 hen and a rooster of this cross, you can‘t get more green eggs. They are only blue or brown.
They also muttered something about “true olive eggers” being different.
I was skeptical, but I thought I would ask you all.
Thoughts?

 

[FuzzyCritters]

False. When you cross the F1s, 75% of the offspring will have blue shells and 25% will have white shells. They will inherit varying amounts of brown pigment, so the eggs will be varying shades of tan, brown, green, and teal.

I don't see the logic in what the people told you. If the potential exists for brown eggs in the F2s, the potential must exist for green eggs as well.

 

[The Moonshiner]

Not true.
The F1 crossed will give you 75% green eggers and 25% brown eggers.
The brown egg genes are different genes then the blue/white shell genes and it's said there's 13 or more genes that could be involved.
Once you cross in brown it is very hard to get rid of it so it's very unlikely to get back to any blue eggers.

 

[Allsfairinloveandbugs]

Not true.
The F1 crossed will give you 75% green eggers and 25% brown eggers.
The brown egg genes are different genes then the blue/white shell genes and it's said there's 13 or more genes that could be involved.
Once you cross in brown it is very hard to get rid of it so it's very unlikely to get back to any blue eggers.

Wait im confused. I know without a doubt you know your genetics. But how can the blue egg gene completely disappear? I thought the above f1 crosses would result in approx. 25% blue, 50% green, & 25% brown?

If a f1 hen carries 1 blue egg gene and one brown egg gene, and a f1 roo does also, wouldnt that mean a 25% chance of getting a f2 with 2 blue egg genes?

 

[The Moonshiner]

Wait im confused. I know without a doubt you know your genetics. But how can the blue egg gene completely disappear? I thought the above f1 crosses would result in approx. 25% blue, 50% green, & 25% brown?

If a f1 hen carries 1 blue egg gene and one brown egg gene, and a f1 roo does also, wouldnt that mean a 25% chance of getting a f2 with 2 blue egg genes?

There's two sets of genes involved.
The shell color genes are simple either blue or non blue (white) Blue is dominate.
The other set is for brown or lack of. There's many genes. At least 13 for the brown coloring. Hence why there's so many shades of brown.
Most brown egg layers carry several of those genes so once you bring it into the mix its hard to get a cross that would happen not to get at least a few.
Make sense now?

 

[TheOddOneOut]

That’s what I thought! I may kindly explain this to them, I may not. But thanks anyways!

 

[The Moonshiner]

Some times it's best to leave things be. Never know where it could end up.

 

[DarJones]

Cross of Brown X Blue is not going to give precisely the same result as crossing Blue X Brown. Reciprocal crosses are affected by the W/Z chromosomes as some of the genes in the porphyrin biopath are on the sex chromosomes.

That said, you can still generalize that crossing a blue egg layer X a brown egg layer and carrying forward to the F2, 1 in 16 will lay white eggs, 3 in 16 will lay some shade of brown egg, 1 in 16 will lay some form of blue egg (caused by recombination of the blue and white genes where the white gene disables the porphyrin biopath), and 11 in 16 will lay some form of egg carrying the blue egg gene with varying overlay of porphyrin producing olive green, teal, spearmint green, tan green, or other slightly nuanced color on top of the blue egg shell.

Moonshiner is partially correct that it is very difficult to recover blue egg layers from crosses with brown egg layers, however, it can be done if you raise enough birds and have enough generations to select. Note from the above that 1 in 16 will lay blue eggs. This means you have to raise 32 chicks (half male, half female) to find one female that lays blue eggs. Even then, she may have only one copy of the blue egg gene as it is dominant. Remember that blue eggs are from a combination of white egg base color with the oocyanin gene. To give a comparison, after eliminating all brown egg layers from my flock, I have about 16 hens currently laying of which 2 lay blue eggs. I did a lot of culling to find those two blue egg layers. The blue egg layers have flaws in terms of feather color and/or type. I have to keep breeding to eventually stabilize silver laced blue egg layers.

 

[Allsfairinloveandbugs]

There's two sets of genes involved.
The shell color genes are simple either blue or non blue (white) Blue is dominate.
The other set is for brown or lack of. There's many genes. At least 13 for the brown coloring. Hence why there's so many shades of brown.
Most brown egg layers carry several of those genes so once you bring it into the mix its hard to get a cross that would happen not to get at least a few.
Make sense now?

Not as much sense as i wish, but thats due to my lack of understanding, not your explanation.

A big reason i've followed your leghorn thread is because after years of choosing hatching eggs to create varied egg colors, ive been crossing different feather colors in my easter egger flocks to get a more colorful flock.

Before i became more interested in feather color genetics, crossed a lot of brown egg-laying breeds with the blue-egg laying easter eggers. Several generations later, still get plenty of blue-egg laying pullets and hens. (Would have been very disappointed if the blue egg gene had been lost, since blue remains my favorite egg color.) Ive chosen both blue and green eggs for hatching, & use only Easter Egger roos with pea combs (meaning they should be carrying at least one blue egg gene), i continue to get plenty of blue egg layers in ensuing generations.

It's too late to think on this anymore tonight. I will revisit this thread tomorrow and maybe it will make more sense then. I may have more questions.

 

[Allsfairinloveandbugs]

@DarJones , thank you very much for your explanation too. My brain is too tired to comprehend any more tonight. But i will Definitely re-read your post tomorrow.