Question about comb genetics

Discussion in 'General breed discussions & FAQ' started by caseebeths, Mar 11, 2014.

  1. caseebeths

    caseebeths Out Of The Brooder

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    If I have a Rooster with a walnut and breed him with a single combed hen...it is to my understanding it will produce all walnut comb babies? ?? Then if I breed those babies with all walnut comb mates will they continue to produce just walnut combed offspring? ?Can sosomeone advice me on this:)
     
  2. Makomd

    Makomd Chillin' With My Peeps

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    If walnut combs are similar to rose combs than you would still have to watch the offspring. In rose combs - Rose combs are dominant. R while single combs are recessive r.

    An R/R bird bred to a r/r bird will result in R/r. Bird shows rose comb, but is hiding a recessive single comb gene (50%).

    Breed this R/r bird back to an R/R bird and you birds will still be rose comb birds but (25%) will still be R/r.

    You could just breed your crossed birds back to a r/r bird and hatch out some eggs if all hatchings show the walnut then it is carrying a recessive single comb gene. if all hatching are walnut it is carrying both walnut genes and I would breed this bird going further and test for other birds that breed pure also.

    I do believe if I read it correctly walnut is a dominant as well over single comb.

    Check out this link it may help as well.


    https://www.backyardchickens.com/a/comb-genetics
     
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  3. Spangled

    Spangled Chillin' With My Peeps

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    Not exactly, but eventually. It seems to be a little more complicated than that.

    I consider a walnut and a cushion to be basically the same because it seems that it's just enhancers or modifiers that account for the difference in shape. (supposed to be P/P R/R or something like that to be "Pure." P=Pea, R=Rose) But, yes, I do understand that some breeds are specifically supposed to have a walnut and some are specifically supposed to have a strawberry. In those cases, it's not the same thing to me.

    What's been happening for me is that when I cross a "pure" walnut or a "pure" cushion with a "pure" single comb is that I very often get another cushion or walnut.

    But when I take that next generation and successive generations and cross again with a single comb, I will sometimes get a bigger pea comb with funny rose comb protuberances on it. I can sometimes get a cushion, but not very often. When I breed that funny comb with another non-pure cushion, I can get a decent cushion or walnut, but I can also get something a little more like a walnut with a spike like on a rose comb or just about anything in between that looks like a big or normal sized pea, rose, or walnut/cushion.

    If I breed my cushion offspring (second generations) back to a "pure" parent or aunt/uncle, I will get some decent cushions, but I still will also get rose and pea comb conglomerations of differing sizes. The decent cushions are not likely going to be R/R, P/P even though they will often show up as a cushion. Their brothers and sisters will often have variations of pea combs and rose combs.

    You may get larger wattles also when you breed in a single combed chicken. (Usually walnut combed chickens have smaller wattles.)

    There are modifiers and enhancers, etc., in comb genetics that aren't well understood yet--not just by me, but by real genetic experts. I've also heard talk of "incomplete dominance," which sounds like a good explanation. Trial and error is the way to get the type of comb you want, if you want something specific. I don't think this is a test mating issue because it's really not something firm that you can plan for very well because of the modifiers and enhancers, etc., which I don't think are specifically identified yet. I believe crests can further complicate the issue also.

    So walnut combs may be dominant over single combs, but it's not dominant in the same way an E/E black chicken being bred to a red chicken (eb/eb) where all the chicks (offspring) will almost assuredly be black because E/E is dominant over (eb/eb).
     
    Last edited: Mar 14, 2014
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  4. Makomd

    Makomd Chillin' With My Peeps

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