My Silver-Laced Australorp(ish) Project

[DarJones]

I gene tested the roosters so all 3 current roosters are homozygous for oocyanin. All of the hens lay blue eggs but otherwise are untested. Given that 1/4 of my roosters were homozygous for oocyanin, I expect a similar to better percentage of the hens are homozygous, especially since all are known to lay blue eggs. So if 1/2 of my hens are homozygous for blue egg, mating with known homozygous roosters, I would expect 75% of the progeny to be homozygous. If 25% of the hens are homozygous, then I expect 5/8 of the progeny to be homozygous. That is 62.5% chance so I rounded it up to 65%. If I am very lucky, it will be closer to 75%. If not, worst case should be 62.5%.

I will DNA test the best of this round of chicks to find enough homozygous hens to produce roosters for the next breeding generation. From that point forward, it is trivial to select for the remaining traits, Rose comb, SLW colors, medium to large body size, SLW feather type, slow feathering, etc. I am also selecting for egg size. I have one hen that lays 70 gram eggs which are in the jumbo range.

 

[3KillerBs]

I loved my White Javas. The Blacks were alright but kinda boring. I always wanted to breed some Blue Jersey Giants onto the Black Javas and re-create the Blue Java.

My Java is mottled. Both Mocha and the sister I sold are big, solid girls with considerable heft in the hand and good feather quality so that they never showed rooster wear. Good birds in the flock, just not my favorites.

Would a double silver laced Barnevelder work for your project? At least you would have straight combs.

Since the goal is an Australorpish bird with a pattern, yes. But I couldn't readily get them at a price within my budget.

The Wyandottes being used in the initial cross have straight combs.

One of my Wyandottes, Victoria, is straight-combed. Her sister, Maria-Theresa, is rose-combed so I will have that to breed out. They're very nearly POL so I should get fresh pictures.

 

[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]

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.

 

[3KillerBs]

Watching with interest. My Cochins are the same way about heat, especially the large fowl. I always joke that they have a melting point of 80° F because they like to spread out on the ground trying to cool off when it's any warmer than that.

View attachment 3229950

Vigor is the #1 thing for me. I want good health and the ability to thrive in my climate under my management system.

For my chickens in the summer, 80F is a cool day even for the less heat-tolerant birds, but the Cochin and the Wyandotte are the first to melt.

I was reading some interesting stuff about breeding for blue on a breeder forum and thought of you, but I wasn't sure if you're going to keep the Blue going or not?

@DarJones did quite a bit of work with Wyandottes and knows a lot about genetics!

Yes, I'm keeping up my Blue Australorps as my primary flock. Australoprs are just about perfect in everything I want out of a chicken, I just want to try adding in my favorite color pattern.

I don't intend to select one way or another for blue vs black in my SLA(ish)'s until well after I have the main characteristics established. Since I'm starting with a blue rooster the blue will be there, but I'll use vigor and type as my main criteria.

 

[NatJ]

How hard would it be and how long would it take to remove the rose comb if one were to start with a normal Wyandotte?

--Some Wyandottes from a hatchery will have single combs, so it takes no time at all.

--Some Wyandottes carry the gene for single combs. Cross them to a chicken with a single comb, and half of the chicks will have single combs. That gives single comb chicks in one generation.

--Some Wyandottes are pure for rose comb. Cross them to a chicken with a single comb, and all chicks will show rose combs but carry the gene for single combs. Cross those chicks to a chicken with a single comb, and half of their chicks will have single combs. That's two generations.

Single comb x single comb should always produce chicks with single combs. So once the rose comb is gone, it should never pop up again, unless you breed to chickens that have rose combs.

 

[nicalandia]

With the right genetics, you can get lacing to extend quite a bit down the tails. I've got it with my birds. I have not tried to analyze the source of the extra lacing. It is still not the full lacing from ER genetics..

Pictures from your birds with that extended lacing.

 

[DarJones]

I've already shown this hen a couple of times. Look closely at the tail.

https://www.selectedplants.com/miscan/slw.hen.jpg

It is storming outside currently. I'll take a few more pics this evening when they go indoors. I will get a pic of this hen so you can see how she looks now.