Egg Color Genetics

Discussion in 'Managing Your Flock' started by Sahwithchicks, Aug 15, 2013.

  1. Sahwithchicks

    Sahwithchicks Chillin' With My Peeps

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    I need some information, please.

    If I where to breed a black copper marans hen that lays a color 6 egg, fairly dark brown, to a bantam Cochin rooster (tinted-to tan egg) what would the offspring color be? Tan to dark tan? white would be genetically implausible, corrected?
     
  2. Sahwithchicks

    Sahwithchicks Chillin' With My Peeps

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    Sorry, it should say what would the offsprings egg color be, if it was a female?
     
  3. donrae

    donrae Hopelessly Addicted Premium Member

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    I believe you're right. White would be out of the mix.
     
  4. Ridgerunner

    Ridgerunner True BYC Addict

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    Yes, white pretty much is not going to happen in that case.

    Basic chicken egg shell color genetics, very basic.

    You have one gene that controls base color. That color is either white or blue. Blue is dominant so if just one of those genes is blue (this gene comes in pairs, one from each parent) the egg base color is blue. If you crack a green or brown egg and look at the inside of the shell after removing the membrane, you can see the base color.

    Think of brown as spray paint that goes on top of that base color. Green is just brown on top of blue. So you get:

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

    Last I heard they had identified 13 different genes that influence brown with several others not yet identified. That’s why you get so many different shades of brown and green. The exact shade you get depends on which of these genes are present, which are dominant or recessive and if they pair up, and how they interact.

    I don’t have a clue which genes or how many in what combination are required to get that dark brown color you often get from a Marans but once you get brown into the genetic mix it can be real hard to get it back out.
     
  5. aoxa

    aoxa Overrun With Chickens

    Could you get white if you do Base blue + no brown as well?
     
  6. Ridgerunner

    Ridgerunner True BYC Addict

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    Aoxa, you know all chickens don’t follow the rules each and every time. Occasionally a hen’s internal egg laying factory messes up and produces something odd. But that is going to be a rare occurrence, not an everyday thing, unless something is really wrong with her internal factory.

    If you cross a chicken that has one blue gene and one white gene with a chicken that has two white genes, about half the female offspring will lay white eggs and half will lay blue.

    I find the longer they are laying after the molt the lighter the brown or green egg gets. Then during the molt they refresh their body and replenish their stores of pigment and are again laying pretty dark eggs. But that’s the brown, not blue or white.

    Genetically the base color is blue or white. Blue + no brown is blue, not white.

    Of course with chicken genetics there are practically always exceptions. I’m an engineer and expect 1+ 1 to always = 2. That blue and white gene is a pure dominant-recessive gene, not partially dominant or incomplete dominant. It should not be dependent on what else is present. If one of those genes is the dominant blue, the base color should express itself. Should. That’s the law of genetics if it is complete unrelenting dominant-recessive, which the blue-white gene is.

    The blue color comes from oocyanin, which comes from bile production. I think zinc is involved. I guess it’s possible the blue could be lighter it the chicken has a shortage of zinc, but the chicken needs zinc for body functions. If it doesn’t have enough zinc it’s not going to be very healthy.

    I don’t know where you are coming from Aoxa, but blue + no brown = blue. You’ve probably got something up your sleeve.
     
  7. aoxa

    aoxa Overrun With Chickens

    I'm curious. They have these super blue layers (Ameraucana x White Leghorn) and a few of my friends have reported white eggs, not blue. But it could just be so pale that they don't notice the tint.

    I've also been surprised by tinted x green and ended up with blue eggs somehow. I expected either green or brown (or tinted)

    For example.. a silkie lays an egg that would be called tinted. It's not white.. it's very, very light brown. How would I end up with blue from this?

    [​IMG]

    Here is my example.. the blue eggs on the right side and upper corner (this would be blue I believe.. correct me if I'm wrong), are from a Easter Egger crossed with a silkie. The little blue egg in the centre is a pure Ameraucana bantam egg. The two green ones are from a green egger naked neck. The tiny whitish cream egg is a polish (white layer) x silkie (tinted) egg. Not white, right? The silkies seem to lay an egg similar in tint to my heritage barred rocks. Maybe a smidge lighter.

    Wow I hope I didn't just way confuse things.

    I am better trying to understand how I got blue eggs from that mix.
     
  8. Ridgerunner

    Ridgerunner True BYC Addict

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    Look closely at those “blue” eggs from the crosses. Are they exactly the same shade of blue as the “Ameraucana” egg? You might look at the inside versus the outside of the shell. Some differences in color can be subtle. It just depends on what the genetics are in the mix. I’ve had some pretty blue-looking eggs from a rooster from a very light brown egg over an Ameraucana hen too but they are not the same shade of blue as the mother laid. Pretty close though.

    Silkies are often crosses. It’s very possible that Silkie has mixed genetics as far as egg shell color as well as everything else. If she is laying a lightly tinted egg it’s very possible there is not much brown in the mix to start with.

    Besides your question was blue + no brown = white, not different shades of blue. Leave it to a woman to change the subject! :he

    Are you saying the Ameraucana x leghorn crosses are laying white eggs? Then some Ameraucana were not pure for blue but were split blue/white. Or are you saying they are crossing the offspring of the Ameraucana/Leghorn crosses and some of the offspring are laying white eggs? Then ¼ of the offspring should lay white eggs.
     
  9. aoxa

    aoxa Overrun With Chickens

    Sorry ;)

    Yes that is what my friends are saying. The eggs appear white. I couldn't tell you for sure if there isn't anything in the Ameraucana that were used for the cross. Everyone knows how shady the backgrounds can be with Ameraucanas.

    I will be checking on the inside of the eggs next time I crack one open and peel back the membrane.
     
  10. Ridgerunner

    Ridgerunner True BYC Addict

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    No reason to be sorry. I think we are friends and I can tease you a bit.

    You’ll often find that theory is one thing and reality is something else. Theory tells you what should happen. Reality often gets in the way of that.

    A lot of times it’s real hard to know what is in the genetic background of chickens. All breeds are developed from crosses. There is no such thing as DNA testing to tell if one is genetically “pure” for a breed. All kinds of surprises can come out of them.

    I once got designer eggs from a breeder to hatch. The chicks came out looking pretty much like they are supposed to. But when I crossed them with a red rooster, a chicken that was “pure” for extended black gave me a red chicken. I’ve had some other surprises from them. You just don’t know what is hiding in that genetic mix no matter where you get the chicks.
     

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