Blue egg gene results with Orp cross....

Discussion in 'General breed discussions & FAQ' started by katelk, Dec 4, 2013.

  1. katelk

    katelk Chillin' With My Peeps

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    I know that the blue egg gene is dominate and I know how genetic work.
    From what I understand, the green eggs come from blue+brown egg genetics according to another BYC thread. However, this was only mentioned in passing and I want to dog deeper because I currently have a flock full of English Orpingtons and want to add a few EE's and see where this blue egg gene takes me.
    I have a black (with a chocolate gene!) Orpington roo.
    If I cross him with a blue egg layer, will I ALWAYS get green eggs(instead of blue) or is there a chance of blue eggs?
    Also, if I get only green eggs, can these chicks be bred out to eventually produce blue? If so, how many generations would that take?
    Does brown+blue always = green?

    Thanks!!
     
  2. Ridgerunner

    Ridgerunner True BYC Addict

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    I don’t know if this is the thread you were talking about. If not, read this thread plus the article Tim linked to, then take two Tylenol and call me in the morning. That stuff is enough to make your head spin. You said you wanted to dig deeper.

    https://www.backyardchickens.com/t/840867/clarifying-brown-egg-genetics

    It’s hard to talk about an EE because there is no standard for EE’s. It’s just a generic name for a chicken that might or might not have some relationship with the blue egg gene. Some people consider any chicken that hatches from an EE to be an EE. By that definition, they may not lay blue or green eggs.

    But let’s consider an EE to be a hen that actually lays a blue or green egg. Let the uppercase letter “O” represent the blue egg gene and the lower case letter “o” represent the white egg gene. The upper case represents the dominant gene, blue. This gene is not a sex linked gene so the hen will have a gene pair at that location on her DNA.

    A hen that has O,O at that gene pair will lay a blue egg and will give all her offspring an O gene. So any of her pullets will lay blue or green eggs no matter what rooster she is mated to. But if that hen has O,o, she will randomly give one or the other to her offspring. If she is mated to your Orpington rooster that is o,o half her pullets will lay “green” eggs and half will lay brown. Just because you hatch a pullet from a green or blue egg does not mean that she will lay a blue or green egg.

    The blue or white gene is just one gene pair that determines the base color. That’s pretty basic genetics. You should not need another Tylenol for that. But brown is controlled by a bunch of different genes. Some of those genes add brown. I just learned from Tim’s article that some genes take brown away. Some modify the other “brown” genes. Some are dominant and some are recessive. Two Tylenol didn’t help me on that.

    Green is basically brown added to blue. A simplistic way of looking at it is that:

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

    We don’t know exactly what an EE might contribute as far as brown genes. The Orpington will contribute some brown genes. Assuming you only hatch green or blue eggs and that your Orpington is the daddy, you should get some shade of green eggs. What shade? It depends on what brown genes the parents contribute, whether they are dominant or recessive, and all that. Only hatch blue or green eggs and you at least have a chance.

    How many generations will it take to get rid of the green and be left with blue? That depends on which brown genes are there to start with and what you cross those pullets with. If you bring in some white or pure blue egg layers, you can get to blue eventually. If you cross the offspring to each other and only hatch the bluest eggs, you can get the eggs a lot bluer. But how long either will take and how far you can get depends on what genes are there to start with and some luck in which genes get passed down. Your ability to select the right breeders will also have big impact.

    Hopefully this will help some.
     
    2 people like this.
  3. nicalandia

    nicalandia Overrun With Chickens

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    Quote:Yes... the brown egg shell polygenic trait will turn blue into green
     

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