My Silver-Laced Australorp(ish) Project

[ikoCRO]

I have been breeding Wyandottes for a really long time and regardless of how many times I change the genetics of the flock, in almost every brood I get about 2% of the birds with a single crest. I remove such animals because they are a breeding error of the breed.
If you talk to any Wyandotte breeder, I believe they will give you such birds (at least that's what I do).
I want to say that I don't think you will have a problem removing the Wyandotte crest and forming a single crest, because it is common in breeding, but you will have a problem with the body shape itself, which is significantly different in Wyandotte and Australorp.
Anyway, good luck!

 

[3KillerBs]

but you will have a problem with the body shape itself, which is significantly different in Wyandotte and Australorp.

Yes, that should be the harder problem.

I figure I'm just going to have to breed back to the Australorps repeatedly, losing the lacing for a generation as I pursue a reasonable approximation of the type.

 

[nicalandia]

I have been breeding Wyandottes for a really long time and regardless of how many times I change the genetics of the flock, in almost every brood I get about 2% of the birds with a single crest.

The single comb mutation is entrenched on the breed and will likely never go away.

 

[DarJones]

The single comb mutation is entrenched on the breed and will likely never go away.

That is only because breeders are not dedicated enough to do the work required. It will get easier soon. There is a preliminary test for rose comb in Germany now. Once a breeder gets all birds homozygous for rose comb on chromosome 7, we should see straight comb chicks eliminated. That probably won't happen any time soon with hatchery birds.

A complicating factor is that straight comb has a very strong reproductive advantage. The R1 rose comb allele whacks a chunk of a gene affecting sperm viability. Pure R1 rose comb roosters produce sperm that is viable for 3 to 5 days where straight comb roosters can last 3 weeks or a bit more. There is an alternative which will require DNA tests to resolve. The R2 rose comb allele retains the inversion for rose comb but repairs the sperm motility gene. With a bit of work, R2 can be incorporated into existing rose comb breeds. This is on my radar as a long term goal with my birds.

 

[nicalandia]

That is only because breeders are not dedicated enough to do the work required. It will get easier soon. There is a preliminary test for rose comb in Germany now. Once a breeder gets all birds homozygous for rose comb on chromosome 7, we should see straight comb chicks eliminated. That probably won't happen any time soon with hatchery birds.

A complicating factor is that straight comb has a very strong reproductive advantage. The R1 rose comb allele whacks a chunk of a gene affecting sperm viability. Pure R1 rose comb roosters produce sperm that is viable for 3 to 5 days where straight comb roosters can last 3 weeks or a bit more. There is an alternative which will require DNA tests to resolve. The R2 rose comb allele retains the inversion for rose comb but repairs the sperm motility gene. With a bit of work, R2 can be incorporated into existing rose comb breeds. This is on my radar as a long term goal with my birds.

That is true, the R1/r+ males will outcompete the R1/R1 males

How will you find a source of R2?

 

[Iluveggers]

That is only because breeders are not dedicated enough to do the work required. It will get easier soon. There is a preliminary test for rose comb in Germany now. Once a breeder gets all birds homozygous for rose comb on chromosome 7, we should see straight comb chicks eliminated. That probably won't happen any time soon with hatchery birds.

A complicating factor is that straight comb has a very strong reproductive advantage. The R1 rose comb allele whacks a chunk of a gene affecting sperm viability. Pure R1 rose comb roosters produce sperm that is viable for 3 to 5 days where straight comb roosters can last 3 weeks or a bit more. There is an alternative which will require DNA tests to resolve. The R2 rose comb allele retains the inversion for rose comb but repairs the sperm motility gene. With a bit of work, R2 can be incorporated into existing rose comb breeds. This is on my radar as a long term goal with my birds.

Here to learn. Shocked about the difference in sperm viability! Would a pea comb have a different length of time as well?

 

[nicalandia]

Here to learn. Shocked about the difference in sperm viability! Would a pea comb have a different length of time as well?

No, The issue is with Rose Comb1 mutation. No other mutation has that issue


You can Search:
The Rose-comb mutation in chickens constitutes a structural rearrangement causing both altered comb morphology and defective sperm motility

 

[DarJones]

How will you find a source of R2?

I don't know yet, but where there is a will there is a way. There are at least 2 breeds I am aware of that have R2 typically as about 1/4 of the birds. Do a search for R2 rose comb allele and several articles will show up that give details. The problem I see is that there will have to be a genetic test specifically for the R2 mutation and that will be difficult. R2 differs from R1 in having the rose comb inversion chained to the sperm motility gene in its entirety, in other words, without the damage from R1. I'm reasonably certain that R2 has occurred more than once over the years though this is based on scant evidence. At minimum, some breeds in France carry R2.

On a positive note, introgressing R2 will be fairly simple with my birds. I just need at least 1 bird with R2 and make crosses to straight comb birds in my flock. Repeat the cross each time to straight comb birds for 6 or 7 generations and save only the rose comb male offspring each time should give a SLW type bird with a single copy of R2. From that point it just takes stabilizing rose comb in the new line.

 

[ColtHandorf]

IIRC, I may have had 2 straightcombed chicks but if I did the snake that ate 7 of the 12 chicks from that batch got the other one.

Ughhhh. I hate greedy rat snakes. This is why I like winter babies. No snakes. Except that in Texas it can be 80 degrees (Tuesday) and then 28 degrees (last night). So it's always a bit of a crap shoot on whether all the chicks make it.

Thank you!

Yeah, the leg color will plague me for a while. But I didn't have access to nice English Orpingtons on my budget.

That's true. And from what it sounds like, it would be a mess to introduce them later as they are laced in a genetically different manner.

Yes, that should be the harder problem.

I figure I'm just going to have to breed back to the Australorps repeatedly, losing the lacing for a generation as I pursue a reasonable approximation of the type.

Yes, I'm sure you'll have to outcross to Australorp again. I wonder if it's easier to get the pattern locked in and then cross your F3 or F4 birds back onto pure Australorp. Breed those siblings together and rinse and repeat to bring in the body shape you're looking for.

 

[JacinLarkwell]

Yes, I'm sure you'll have to outcross to Australorp again. I wonder if it's easier to get the pattern locked in and then cross your F3 or F4 birds back onto pure Australorp. Breed those siblings together and rinse and repeat to bring in the body shape you're looking for.

That's what I thought