Anyone familiar with the Breda comb? How is it inheritted. Are there many breeds that carry this trait? Thanks, Dan

According to Punnett and Bateson the Breda's combless phenotype is inherited as a simple recessive. The breed is actually a combless duplex combed breed. If you cross a single combed bird to a Breda you will get birds with duplex combs.

I think that there may be more than one way to get this combless phenotype. I tried to create a blue egg laying crested breed and obtained some Breda type combs in the fourth generation. These hens laid blue eggs, but only had two small papilae where their duplex pea combs should have been. They had large crests so I think that they were PP DD CrCr MbMb. Muffs and beards (Mb), Pea comb (P), duplex comb (D), and crest (Cr) are known to reduce comb mass. I think that all of these genes combined to produce the combless birds.

I breed the Ameracanas and have found that if you cross the male with a pea type comb to a female with the same type the combs get bigger and bigger so only keep females with small combs with a single ridge and breed these to the males with the pea type comb. From this about one out of 5 male offspring end up having a single ridge type comb and the females have about half single ridge and half the wider, pea type comb. I actually have never heard of the Breda comb, just how combless are these chickens?

Rokimoto, was there a reason you had selected for duplex combs in your blue egg laying crested?

Anonymous, by "single ridge type" comb, do you mean a normal single comb like on a barred Rock?

I selected for duplex to reduce the comb mass and increase the crest size. Crest size is inversely related to comb mass. I had pea comb in there because it was linked to the blue egg gene. In about 5 generations I obtained some very well crested birds that laid blue eggs, two of them did not have any visible combs just two small dots that looked like a duplex comb had tried to grow. Because they laid blue eggs I assumed that these pullets had pea comb as well as duplex comb, but I never test mated them. I got a job in Michigan and gave all my stock away. These two combless pullets could have been PPDD.

I've never heard of a single ridge type pea comb, but you can breed for smaller pea combs using comb size modifiers. Just making the bird PP doesn't produce the smallest pea comb.

Ron Okimoto

I don't like the looks of the large nostrils associated with (DV) v-shaped duplex. Do you think I could still get reduced comb mass using (DC) buttercup duplex with (R) rose and (Cr) crest? That way I could avoid the large nostrils.

One thing that I have noticed about DC is that it may reduce comb mass, but it makes the comb thinner. This would be counter productive for trying to make the combs freeze resistant. Pea comb may reduce the leaves of the comb, and you may get a smaller pea like comb if you combine Dc and P. It may be worth a try, but I don't know what you will get.

Crest is not a very utilitarian trait because crests are subject to lice infestations. If you don't like the cavernous nostrils you may have to stick with the walnut comb PPRR like they have in Chanteclers unless DC works out for you. DC does not form the cavernous nostrils unless it is heterozygous with the DV allele.

The genetics of the Houdan staghorn-leaf-type duplex comb is unknown, but it may be the DC allele combined with crest. For some reason Crest reduces the comb length (seems to chop the comb in half) and pushes the comb to the forehead. This could cause the buttercup duplex comb to look like the Staghorn type you find in some lines of Houdans. If you want to try crest and DC look around for a Houdan line with the staghorn type comb. Some Houdans are pretty stocky birds if you are also trying to make a utility fowl.

Rose comb is problematic. It does reduce fertility due to the low lifespan of the sperm after insemination. Sperm from homozygous rose comb males become inviable soon after insemination. If you have a small number of females with a male you won't notice the effect because the male can mate will all the females on a regular basis, but in commercial conditions the fertility is noticably less. You probably would get a smaller comb by combining rose and buttercup.

To one of your other posts, I copied the qualitative genetic chapters out of Crawford 1990. It was cheap compared to the cost of the book. These copies got pretty tattered and yellowed, but now I have the book. It's one of the wonders of laboratory start up funds (you get to buy books that you need for your research).

Ron Okimoto

To ubuddy
By a single ridge type comb I don't mean like a barred rock, but rather a slight ridge with small knobs along the top

The single ridge sounds like a low pea comb. Pea usually has three ridges of bumplets with the middle ridge being more prominent. Two of my blue egg laying silkie mixes just have an oblong bumpless mound about 4 times as long as wide. My pea combed birds usually have much smaller wattles.