True olive egger

[Toon]

I've been messing around with genetics (on paper) lately, and I don't think it's possible, but maybe I'm missing something: is it possible to make a 'breed' (not rlly a breed, more like a cross) that will breed true in olive egg colour? With no brown or blue coming from it? One that will breed true for multiple generations?

 

[Brahma Chicken5000]

It’s definitely possible, but it will take a few generations until you have what you want. If you want birds that will always lay olive eggs you will need to start by crossing say a Marans cock who hatched from a very dark brown egg and who’s sisters lay dark brown eggs to a blue egg laying hen. The F1 offspring will all lay olive eggs granted that your hen is homozygous for the blue egg gene. Now you would cross the F1s together to get F2s. However you will end up with 50% homozygous for the blue egg gene (green or olive egg layers), 25% heterozygous for the blue egg gene (green or olive egg layers), & 25% homozygous for the non blue egg gene (brown egg layers). Now you will take the F2s that lay olive eggs and you will need to test mate them to see if they carry 2 blue egg genes or just 1. To test this you will need to cross F2 cocks and hens to brown or white egg laying chickens. If an F2 Olive Egger is homozygous for the blue egg gene then all its offspring will lay blue, green, or olive eggs. If an F2 Olive Egger is heterozygous for the blue egg gene then 50% the offspring will lay blue, green, or olive eggs and the other 50% will lay white or brown eggs. Once you have ascertained which F2 Olive Eggers are homozygous for the blue egg gene you will cross them and your F3s will be guaranteed to lay green or olive eggs. I believe that it is hard to guarantee that the dark brown egg genes pass on to the offspring in F2 progeny. That’s why back crossing to Marans, Welsummers, or Barnevelders is done to improve olive egg color.

 

[Toon]

It’s definitely possible, but it will take a few generations until you have what you want. If you want birds that will always lay olive eggs you will need to start by crossing say a Marans cock who hatched from a very dark brown egg and who’s sisters lay dark brown eggs to a blue egg laying hen. The F1 offspring will all lay olive eggs granted that your hen is homozygous for the blue egg gene. Now you would cross the F1s together to get F2s. However you will end up with 50% homozygous for the blue egg gene (green or olive egg layers), 25% heterozygous for the blue egg gene (green or olive egg layers), & 25% homozygous for the non blue egg gene (brown egg layers). Now you will take the F2s that lay olive eggs and you will need to test mate them to see if they carry 2 blue egg genes or just 1. To test this you will need to cross F2 cocks and hens to brown or white egg laying chickens. If an F2 Olive Egger is homozygous for the blue egg gene then all its offspring will lay blue, green, or olive eggs. If an F2 Olive Egger is heterozygous for the blue egg gene then half the offspring will lay blue, green, or olive eggs and the other 50 will lay white or brown eggs. Once you have ascertained which F2 Olive Eggers are homozygous for the blue egg gene you will cross them and your F3s will be guaranteed to lay green or olive eggs. I believe that it is hard to guarantee that the dark brown egg genes pass on to the offspring in F2 progeny. That’s why back crossing to Marans, Welsummers, or Barnevelders is done to improve olive egg color.

Cool! Something to try, but when i'm older and have too much time on my hands thank you so much!!!

 

[Brahma Chicken5000]

To test if the f2 are homozygous, that's only for the males, right? Because the hens you can see by the egg colour. Or am I mistaken?

You need to do it with the males and the females. You won’t be able to tell which females are homozygous for the blue egg gene and which are heterozygous just based on egg color. Both will lay green or olive eggs.

But after crossing f2 to f2, wouldn't you just get 50% 25% and 25% again? Or is it more complex than that?

Not if you test mate your F2s and only bred the F2s that are homozygous for the blue egg gene.

 

[Toon]

You need to do it with the males and the females. You won’t be able to tell which females are homozygous for the blue egg gene and which are heterozygous just based on egg color. Both will lay green or olive eggs.

Not if you test mate your F2s and only bred the F2s that are homozygous for the blue egg gene.

Ok, perfect!

 

[aart]

If I put an Araucana cock over a Welsumer hen, will any pullets that result lay olive eggs?

It's possible.....if the cock passes a blue shell gene.

 

[aart]

thanks @aart . He seems to be a pure Araucana, so could he have any other colour gene to pass on?

Shells are either white or blue.
There are two genes for shell color and I believe they are dominant,
so if just one passes the shells of female offspring will be blue.
If your Araucana is pure, he should have two blue shell genes,
and no brown coating genes.
The brown coating is a whole other string of genes, at least a dozen.
That's about all I know....and it may or may not be correct.

Go ahead and hatch some from that pair,
make sure no other cock/erels are present for at least 3 weeks.
Probably have at least a 50-50 chance of an olive egger from the pullets produced.

 

[ASteelman]

It’s definitely possible, but it will take a few generations until you have what you want. If you want birds that will always lay olive eggs you will need to start by crossing say a Marans cock who hatched from a very dark brown egg and who’s sisters lay dark brown eggs to a blue egg laying hen. The F1 offspring will all lay olive eggs granted that your hen is homozygous for the blue egg gene. Now you would cross the F1s together to get F2s. However you will end up with 50% homozygous for the blue egg gene (green or olive egg layers), 25% heterozygous for the blue egg gene (green or olive egg layers), & 25% homozygous for the non blue egg gene (brown egg layers). Now you will take the F2s that lay olive eggs and you will need to test mate them to see if they carry 2 blue egg genes or just 1. To test this you will need to cross F2 cocks and hens to brown or white egg laying chickens. If an F2 Olive Egger is homozygous for the blue egg gene then all its offspring will lay blue, green, or olive eggs. If an F2 Olive Egger is heterozygous for the blue egg gene then half the offspring will lay blue, green, or olive eggs and the other 50 will lay white or brown eggs. Once you have ascertained which F2 Olive Eggers are homozygous for the blue egg gene you will cross them and your F3s will be guaranteed to lay green or olive eggs. I believe that it is hard to guarantee that the dark brown egg genes pass on to the offspring in F2 progeny. That’s why back crossing to Marans, Welsummers, or Barnevelders is done to improve olive egg color.

Thank you for the great explanation of test breeding! I have some F1s that I am going to move forward with but I wasn't quite sure what to do after I get to the F2 generation.

 

[Brahma Chicken5000]

Chicken genetics is really hard. I am trying to understand but struggling. If I put an Araucana cock over a Welsumer hen, will any pullets that result lay olive eggs?

If you are using a pure Araucana then all resulting pullets from your cross will lay green-olive eggs depending on how dark of an egg the mother lays.

 

[Toon]

If you end up with Olive Eggers who are homozygous for the blue egg gene and you cross in a dark brown egg layer all the F1 offspring will be heterozygous for the blue egg gene.

So if i cross a true olive egger to a brown layer, and the offspring to each other, i'll have to test-breed again to a white layer?
And when doing that, what is it i'm looking out for?