blue egg genetics

Discussion in 'General breed discussions & FAQ' started by cmfarm, Oct 2, 2012.

  1. cmfarm

    cmfarm Chillin' With My Peeps

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    I did a search and found a good thread about this but still have a few questions. I am buying some eggs from a guy close to me. He has Ameraucana chickens (to keep this simple we will asume they really are and not EE's) and RIR hens. His rooster is an Ameraucana cross with a black Australorp. So this is what I am asuming will happen with the egg color (please correct me if I am wrong) :
    The Amer. hens crossed with the rooster will most likely create chicks that lay around 75% blue eggs and 25% green eggs (with maybe a few brown eggs in between?). And the RIR hens crossed with the rooster will create hens that lay 50% brown, 25% green and 25% blue?

    I now there are a lot of variables in this so I'm not even sure if it can be figured out. But I know there are some people on here that really know there genetics so I'm sure someone can set me straight.
     
  2. nicalandia

    nicalandia Overrun With Chickens

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    sorry, 100% of these cross hens will lay green eggs, the shade will very, but they will all lay green eggs, why? well thats easy, the brown egg shell trait its not a single gene, its a polygenic trait and some of those genes are sex links, once you introduce the brown egg trait to a blue or white egg breed its almost impossible to get rid of... its very hard to get rid of, you need to go back to the blue egg parent and bred his/her children back to them, wait for the hens to start laying(6 months at least) select the one with the lighter green tone and go back to the blue egg parent again, repeat(6 month wait again) and select the lighter shade green ones or if you are lucky you may at this point get a blue egger... you see how hard this is?
     
  3. cmfarm

    cmfarm Chillin' With My Peeps

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    Than how is it that with EE you get blue, green, pink, and brown eggs?
     
  4. mstricer

    mstricer Overrun With Chickens

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    It is what the Ameraucana is mixed with that gives that color. I you take EE hens and cover with a Marans rooster you can get this
    [​IMG]
    The lighter the brown the lighter the shade of green. I used 6 EE's and only hatched the blue eggs, none of the green ones were used, I heard you don't get the same effect by using green eggs. I have never seen a pink egg from any EE's I've owned, I do have a NH that lays almost pink eggs so I bred her to the Marans to see if I can get some pinker eggs. Going in the incubator next week? Who knows
     
  5. nicalandia

    nicalandia Overrun With Chickens

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    you dont get those colors from the same hen, so different genetic background
     
  6. cmfarm

    cmfarm Chillin' With My Peeps

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    I know they don't come from the same hen. Well, I guess they will have pretty shades of green eggs then. Thanks for everyones help![​IMG]
     
  7. cmfarm

    cmfarm Chillin' With My Peeps

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    One more question. Since the rooster (agian 1/2 BA and 1/2 Amer.) mixed with the RIR hens will produce 3/4 percent brown egg genes, do you still think the eggs will be green or just brown?
     
  8. nicalandia

    nicalandia Overrun With Chickens

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    if the hens have pea combs, they will lay green eggs, if the hens have single comb they wont, simple as that... you have to understand that the blue egg gene will not segregate separately and ALL of the pea comb birds will lay gree eggs
     
  9. Cedarknob

    Cedarknob Chillin' With My Peeps

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    The gene for blue [that may look green] eggs will separate from the pea comb, its just a lower percentage event. The Cream Legbars are a single combed breed. Since he's starting with a bird that is heterozygous for a pea comb and blue eggs [which will appear green due to his Australorp parent] he will not be getting 100% green eggers; he will get 50% green eggers from the RIRs. There's better than a 90% probability that the pullets with pea combs will lay green eggs, same odds that the single comb pullets will lay brown eggs.

    ETA: Even pure Ameraucanas often lay greenish eggs; but this pullet egg came from an Ameraucana X Cornish Rock pullet. Because that strain of CX lay lightly tinted eggs, this egg is closer to blue than green to me.


    [​IMG]

    Their pullet eggs are larger than most, but this one had a soft shell between the yolk and the white, so is extra large.
     
    Last edited: Oct 2, 2012
  10. Sonoran Silkies

    Sonoran Silkies Flock Mistress

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    Okay, let's assume the ameraucanas are pure for the blue eggshell gene (O/O). Therefore all their offspring will inherit a copy. Assuming that the rooster has one copy of the blue eggshell gene and one copy of not-blue eggshell (O/o+), about half the offspring will inherit two copies of O and about half will inherit only one copy. So based simply on that, all will lay an egg with a blue eggshell; some will have more blue as they have two copies of the gene. Now a green egg is made by adding a layer of brown pigment over the outer surface of the eggshell, Assuming all ameraucana ancestors contributed very little in the way of brown egg genes, it is all up to the australorp parent and what all genes he carries, and realize that his offspring will not inherit more than one copy of each. Australorps are not known for laying a dark brown egg, and with at most one copy of each of the brown egg genes, that will be even lighter. So, from the ameraucanas, expect pale green eggs; some may appear closer to blue; it just depends on what that individual bird inherited.

    Okay now pair the same rooster to an RIR, who lays darker eggs, and has no copies of the blue eggshell gene. About half of the birds will be O/o+ and the other half o+/o+. They will all inherit brown egg genes from both parents; since RIR eggs tend to be a slightly darker brown than australorps' the O/o+ birds' eggs are likely to appear more green, but once again, it really can vary from one bird to another, depending on the exact genetic soup that bird inherits. So, about half green, about half brown.
     
    Last edited: Oct 2, 2012

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