Comb Genetics

[Sonoran Silkies]

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First hand experience beats hand book knowledge...

Rose Comb is suppose to be one of the few "Completely Dominant" gene(most are incompletely dominant) that's why most wyandotte breeders keep getting single comb hatch from time to time... but as you pointed out there are other factors that could affect the outcome..

Double genes for rose comb also lowers fertility in male birds; does not affect females.

 

[nicalandia]

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that much is true, that's why som people breed for heterozygous Rose combs, since most will look identical to homozygotes but will have higher fertility rate..

Ron O. :

Rose comb is considered a completely dominant trait. There may be copy number differences in comb mass, but the structure of the comb is not intermediate. The recessive allele of single comb (r) can be effectively hidden by the dominant rose (R) allele. There is also natural selection involved in maintaining the r allele in Rose comb breeds. RR males are less fertile than Rr heterozygous males, and the sperm from Rr males outcompetes the RR male sperm in a population.

Wyandottes seem to segregate the most for single comb. The reason for this is probably due to a lot of factors, like their similarity to Rocks (the common exchange between the two breeds) and the fact that they have heavy vent plumage that interferes with mating. Rr males would have an advantage in fertility.​

 

[Gresh]

If I were to cross a pea-combed Oriental to a Leghorn, would I get single-combed offspring if the pea-comb was impure? What if I cross a Sumatra to this cross? Would I get pea-combed birds?

 

[Ducks and Banny hens]

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Right, but if the rose combed bird was pure for rose comb, the offspring would all be rose combed.

Pea comb and rose comb combine to give a walnut comb.

I think that should be cushion, not walnut...

I beleive Cushion, Walnut and Strawberry are all synonymous.

 

[Ducks and Banny hens]

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Gresh, I think if the Peacomb was pure you'd get all impure peacombs, and if it were impure, you'd get half single- and half impure peacombed birds. So you'd get single combed offspring, but only about half. I'm not sure what the sumatra's comb is so I can't help you with that, sorry.

 

[Sonoran Silkies]

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I think that should be cushion, not walnut...

I beleive Cushion, Walnut and Strawberry are all synonymous.

Minor differences between them; genetically it is modifiers. Strawberry combs are rough while cushion combs are smooth. Walnust combs should have a transverse crease through it.

 

[Sonoran Silkies]

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Gresh, I think if the Peacomb was pure you'd get all impure peacombs, and if it were impure, you'd get half single- and half impure peacombed birds. So you'd get single combed offspring, but only about half. I'm not sure what the sumatra's comb is so I can't help you with that, sorry.

Pea and single combs can combine into some pretty odd shapes. I've seen birds where the comb started out in the front as a sort of extra thick single comb and split into two single combs. Nothing like a V comb. Don;t have that bird any more or I would try to take a photo. On another bird it looked sort of like a thick single comb where all the points had been dubbed off--I may have photos of that.

Note that single comb is incompletely dominant, not dominant like rose comb.

Sumatras have pea combs, so the offspring of pea comb X pea comb will be a pea combed bird if both are pure for it.

 

[nicalandia]

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I beleive Cushion, Walnut and Strawberry are all synonymous.

Minor differences between them; genetically it is modifiers. Strawberry combs are rough while cushion combs are smooth. Walnust combs should have a transverse crease through it.

that's correct

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[pinkchick]

Hello Everyone!

Since this thread is about comb genetics and I see a few different types of combs discussed here...Can I add one more to the list for discussion while all of your great brains are located here in one place??

Carnation Combs - Anyone have any knowledge of them and the genetic factors behind them?

I can find very limited information about it.

I have emailed Penedesenca breeders inquiring and have heard nothing in response.

 

[Ducks and Banny hens]

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In post #27 Sonoran Silkies posted about a Carnation combed birded from a Pea-Single cross.