Breeding back Olive Egger Hens

[ChelsisChooks]

I have an Olive Egger hen that was born to a Black Copper Marans x Ameraucana.
If I breed her to a BCM the resulting chicks will be 50% Olive Eggers and 50% brown egg layers, correct? Because this olive egger hen only carries one blue egg laying gene and will pass it on approx 50% of the time.

But if I cross her on an Ameraucana rooster will the resulting chicks all be olive eggers?
Basically does an Olive Egger always pass on the genes to make a brown egg? I assume if this is true it is because there are multiple genes are work that make a hen lay brown and it is very unlikely she would not pass on any one? So is it just unlikely or is it impossible for an olive egger to fail to pass on the brown laying genes in this cross and thus produce only a blue egg?

 

[MistyandLuna]

I’m not totally sure since I’m not familiar with chicken genetics, but I hope you find an answer to this!!

 

[Nigel27]

I think you might get 50% with two blue genes and 50% w one (OEs) but I don’t know if you can carry two copies of the blue gene and still carry the brown. Would definitely be interested to find out

 

[LadiesAndJane]

You get what is called a dull spearment layer. This chart has been posted multiple times on BYC, including me. Nice visual but does not explain the exact genetics.

 

[Nigel27]

You get what is called a dull spearment layer. This chart has been posted multiple times on BYC, including me. Nice visual but does not explain the exact genetics. View attachment 2503111

Wow! I wonder how accurate this is? 50% would have two blue genes and 50% would have one. I wonder which one is dull spearmint?

 

[AusHen]

If you bred her to a BCM each chick with have a 50/50 chance of having olive or brown genetics, shade and darkness would depend on the BCM genetics. If you bred her to a pure Ameraucana each chick will have the genetics for green, they would be a lighter colour than the mothers olive egg so more likely a medium to light green rather than "olive".
Once you have any brown pigments it's extremely hard to remove them so although this chart has blue, shades of green are far more likely.

*Edit to correct photo

 

[ChelsisChooks]

If you bred her to a BCM each chick with have a 50/50 chance of having olive or brown genetics, shade and darkness would depend on the BCM genetics. If you bred her to a pure Ameraucana each chick will have the genetics for green, they would be a lighter colour than the mothers olive egg so more likely a medium to light green rather than "olive".
Once you have any brown pigments it's extremely hard to remove them so although this chart has blue, shades of green are far more likely.
View attachment 2503147
*Edit to correct photo

Thank you!!!! This is just what I suspected. I know that there are many genes involved with the brown so it makes sense that it would pass forward 99% of the time but the blue is singular in an olive egger so should only pass 50% of the time. It was easier to get when I realized that an olive egger is just a dark brown Easter egger and so the genetics should be the same (Easter eggers don’t breed true).

 

[ChelsisChooks]

You get what is called a dull spearment layer. This chart has been posted multiple times on BYC, including me. Nice visual but does not explain the exact genetics. View attachment 2503111

I think this chart shows how to get the darker Olive color but doesn’t show the possibility that the F1 oliveegger crossed back to dark brown layer can produced brown eggs.

 

[ChelsisChooks]

I think you might get 50% with two blue genes and 50% w one (OEs) but I don’t know if you can carry two copies of the blue gene and still carry the brown. Would definitely be interested to find out

i think that there are a few people who have bred green layers that breed true (carry two copies of blue gene) like Whiting True Green and Silverrud Isbar. There is a genetic formula for how to create this over many generations

 

[Nigel27]

I read BCM cockerels are preferable when making OE because they pass more of the brown apparently