How to... Single comb to Pea comb

[tadkerson]

Pea comb is incompletely dominant over single comb. Heterozygous birds (Pp) will have an intermediate comb, a single comb with three rows of spikes on the top. Birds with smaller single combs crossed with pea comb birds will produce a small blade with the three rows of spikes on top. Much more noticeable on the male.

Rose comb is dominant over single comb. single comb (p/p r/r) X rose comb (p/p R/R) = rose comb (R/r) I have a hypothesis that the single comb gene does influence the rose comb to some extent.

Duplex comb is incompletely dominant to single comb. Heterozygous duplex/single combed birds produce a single comb that is split in the back with a circle of spikes. Much more noticeable on the male.

There are modifiers that can effect the rose, pea and single combs. This is why you get variations in the combs of birds. Especially when the birds are walnut combed (P/P R/R).

The walnut comb is produced because P is incompletely dominant to R or R is incompletely dominant to P ; either way they both influence each other and you get a walnut comb. With some modifiers you get a cushion comb or a strawberry comb and the other variations of the comb.

Tim

 

[Chris09]

Quote:
Tim,
From what I have seen in Rhode Island Red's (R.I. Red's), when you cross a Rose comb to a Single comb you will get a good percentage of the two combs. The Single comb's from this cross seem to be the unchanged for the most part but some of the Rose comb's do change. The rose comb is larger in over all size, spikes larger, the points on the comb are also larger and some tend to get a hollow center.
I don't know if this work with your hypothesis or not but it is what I have seen in the breeding of R.I. Red's.

Chris

 

[usschicago1]

Quote:
Umm, that is PP x pp giving Pp F1s--all will display some variation of a pea comb; however, they will probably not be nearly as well formed as PP combs, and many will display evidence of the p allele.

Pp X Pp will give 25% PP, 50% Pp and 25% pp.

Of course you have all the other breed and variety charactersitics to deal with as well.

 

[big medicine]

Quote:
Are you aware of any good photos or drawings that distinguish the variations of walnut,cushion,ect. of PR combs?

 

[Sonoran Silkies]

Quote:
That sometimes occurs, but not always--not sure why. Sometimes you'll simply get a pea comb that is very tall--as if it were sitting atop a single comb instead of the sawtooth points.

 

[Sonoran Silkies]

Quote:
Pea Comb Isnt 100% dominant its 75%
So some of the offspring with be Single

Not an accurate statement; you're mixing apples and oranges. Pea comb is incompletely dominant. Always. Meaning that there is an intermediate phenotype difference between a bird who carries two copies versus a bird with one copy. Some of the other posts give examples.

I believe your percentage is likely based upon breeding birds who both carry only one copy (at least that is hte only way I can come up with 75%).

 

[Sonoran Silkies]

Baybrio, the last portion of the daigram you posted has a mistake; F1 birds are RrPp not RrPP. I didn't rework the two-gene punnet square to see if the numbers are accurate in hte 1st table.

 

[Kev]

Baybrio,

You could greatly simplify it by crossing with a pea comb, and then just select the best bird with a pea comb from each generation and breed it back to a pure Sussex. You should get the coloring back relatively quickly with that method. Plus, pea comb is incompletely dominant which means you have it easy as for telling which birds have it. Could even cull right from hatch etc. Could even get away with hatching fewer chicks with this method instead of having to set larger number of eggs if you do sibling crosses before the color and type is achieved.

Once you have birds with the type and color you're happy with, finally cross two with pea combs for the PP birds.

Keep in mind, Brahmas are feather legged. Can be very difficult to clean up the legs after a cross with feather leg. I'd suggest finding out the genotype of the Sussex coloring and what E base they are on and try to get a pea combed bird with a 'compatible' genotype to make it much easier to get back to the Sussex coloration. Who knows, maybe a Dark Cornish/Asil would be your best outcross..... (have no idea what Speckled Sussex genotype is).

 

[RAREROO]

Quote:
I agree, I've never seen or heard of a breed that comes in both single and pea comb, there are some that come in single and rose come, ( RIRs and Dorkings for example) maybe that's what your thinking of. Any if you did this, I don't think you would be able to call whatever you get a Sussex because the standard does recognize them as a pea or rose combed breed. But regardless, if you wanted to breed for a pea or rose combed mixed bird with the color and qualities of the SS, that shouldn't be too hard. I think it would be best to use a Buff Brahma if you want a peacombed bird, or a Rose combed RIR, if you want a rose combed bird. Or maybe you could think about using Spangled Russian Orloffs since they are the same color as the SS, and they have pea combs, but the have beards/muffs.

 

[Baybrio]

Wow, it will take me some time to digest all of this.

Bigmedicine, I was also thinking I'd better get a clearer idea of what these comb types look like. I found this:

at http://edis.ifas.ufl.edu/ps027 accessed 1/10/10

To make it worse are photos of rose and walnut comb in silkies at this site: http://reocities.com/Petsburgh/6624/ This page also talks about blue egg genetics in Turkens in Australia.

I find it hard to really see a definable difference - so much to learn on my part.

Then there is our own comb description BYC page with links to other BYC comb pages (which I just found) https://www.backyardchickens.com/web/viewblog.php?id=9280

and this which I also just found: https://www.backyardchickens.com/web/viewblog.php?id=9280-Comb_Genetics which explains exactly what I've been reading on this thread in some detail.


Sonoran Silkies, I do see the mistake in the diagram I posted. The diagram makes more sense to me with your correction.

NYREDS you mentioned that you didn't know any breeds that came in both pea comb and single comb - you folks are good! I went back to where I thought I had read that and sure enough I should have said rose comb and single comb.

You also stated: "It might be possible to ultimately produce something that looked like a pea combed Speckled Sussex but it would be a years long process." I think its going to take years for me just to figure out what I've read today. I don't mind taking the time if I can at least figure out where to start. I have a long attention span, you must have this to raise horses. Mares cycle once every 21 days, miss a cycle, wait a month to rebreed. Gestation = 11 months. Then if your lucky you get one foal that may or may not be what your looking for, if not start again which takes another year. If the foal is just what you want, then its another 4 - 5 YEARS before you can really begin to show the horse. So that's at least 6 years in the making for my sport! Just think how many generations and individuals I'll see from the Speckled Sussex in 6 years! (And the chickens eat and poop much less)

So I'm out to feed the parents of my future Rose Combs????.