Hardcore Autosexing genetics questions

[Bluegenes]

Hello,
I used to be a member but lost my login and have returned since I just move to the country and can finally have roosters. I have had chickens most my life, but in the city my desire to hatch chicks was limited to ordering eggs and incubating, and to a smuggled Serama rooster in my basement. But I have delved quite deeply into pigeons, and am especially interested in genetics in poultry. After learning pigeon genetics, chicken genetics seems relatively easy, but still is one of the most fascinating aspects of the hobby. I am especially interested in the genetics of autosexing because it is incredibly interesting and useful for selling chicks locally. I also am a fan of all the "extra" genes in chickens, crests, leg feather, and especially beards. If I could have every bird I keep have a beard on it that would be fine with me!

I am starting to think about my breeding goals, and I plan to do a couple autosexing projects in the next few years, starting with an autosexing EE project, using Legbars, Ameraucanas, and Bielefelders. Besides being autosexing and laying blue/green eggs, the goal is a calm/personable chicken that lays well, is beefier than most EEs, bearded, crested, and pea combed.

I also have some other projects floating around in my head, so I was just curious and have a few questions.

I know that sex-linked barring is usually a key component, but are there any of the other sex lined genes (like Chocolate) that can produce autosexing birds that breed true?

And for traditional barred sexlinks, what base colors can work? I know wildtype and partridge do, and wheaton does not since wheaton chicks are yellow. I assume it would also not work on black or birchen?

What about modifying genes? I'm guessing a gene like mottle would not effect it since it doesn't show on chick down. Are there any modifying genes that are incompatible with autosexing?

For example, would two doses of Blue dilute a chicken enough to make sexing impossible? I assume Lavendar would also dilute a chicken too much to be sexable?

What about genes like Colombian, Darkbrown, Laced, Melanotic, Charcoal, Mahogany, Dilute, Cream (either ig or Cb), Silver, or any of the I series genes?

Alot of questions I know, so thanks in advance!

 

[The Moonshiner]

When you cross those hybrids you will lose the ability to sex them all at hatch.
You'll get about half barred and about half non barred of both sexes.
You'll also get about 75% blue egg layers and 25% that won't lay blue.

 

[The Moonshiner]

What you did was use a non auto sexing non sex link rooster over an auto sexing hen and created sex link offspring.
If using an auto sexing rooster over a non hen you wouldn't have been able to sex them.
An auto sexing breed can be bred to a different auto sexing breed and produce auto sexing offspring.
Yes after that first cross you lose the ability to produce sexable offspring no matter if breeding them together or back to an auto sexing bird.

 

[sylviethecochin]

If you're going to go ham I would suggest investing in a couple of poultry genetics books. Then finding as much information on the existing auto sexing breeds. A lot of the information on how the specific breeds were created are either lost or guarded proprietary information. You can kind of reverse engineer with piecemeal info available on the internet. The biggest thing that will be the "Easter egg hunt" for will be how many generations and at which point the crosses were made.

Actually, you reminded me of the site I forgot to link: Definitely not piecemeal information.

 

[nicalandia]

So, just adding a question in here. If you had two different breeds of autosexing chickens would the result be autosexed chicks? Like if I had a Cream crested legbar hen with a Bielefelder rooster would the chicks be autosexing?

Yes, they will be autosexed since they are both based on e+ wildtype e allele and the sex inked barring gene.


Chicks from a cross of two autosexing pure breeds are also autosexing.source: http://www.steepleducks.co.uk/poultry.htm





The site has been taken down(source) so here is a snap shot of 2012 from the Wayback Machine(got luck here, some pages are lost for ever)
https://web.archive.org/web/20110617223853/http://www.steepleducks.co.uk/poultry.htm

 

[Notaneggspurt]

If you're going to go ham I would suggest investing in a couple of poultry genetics books. Then finding as much information on the existing auto sexing breeds. A lot of the information on how the specific breeds were created are either lost or guarded proprietary information. You can kind of reverse engineer with piecemeal info available on the internet. The biggest thing that will be the "Easter egg hunt" for will be how many generations and at which point the crosses were made.

 

[Cyprus]

@sylviethecochin really hit the nail on the head here.

 

[mandelyn]

In a fit of frustration I did a Hybrid with Legbar hens and a Twentse (Kraienkopp), when the Twentse failed to hatch pure. The Hybrids hatched fine! They were also auto sexing with the gold Duckwing, the pullets came up non barred and the cockerels were barred.

They came up really consistent, I plan to do hybrid to hybrid to see what happens there. Also outcrossing them again to Bresse, to see if I can widen them out in body type. Not sure what the coloring will do with that, more focused on improving dual purpose type.

They're not as flighty as the pure Legbars, the eggs are beautiful! Blue with good shape/size and nice shells.

 

[nicalandia]

@nicalandia what are bielefelders genetically?

They are wild type e+/e+ and sex linked barred on a gold based s+/s+

The females are of a dark wild type base(as shown by their well defined barring pattern as opposed to the Cream Legbar pullets) but well defined salmon breast.

 

[Chooks man]

So once you do 1 outcross with an auto sexing breed, the auto sexing is gone forever, 0% likelihood, even if you breed back to the auto sexing breed?

What you did was use a non auto sexing non sex link rooster over an auto sexing hen and created sex link offspring.
If using an auto sexing rooster over a non hen you wouldn't have been able to sex them.
An auto sexing breed can be bred to a different auto sexing breed and produce auto sexing offspring.
Yes after that first cross you lose the ability to produce sexable offspring no matter if breeding them together or back to an auto sexing bird.

if you selecting a barring gene s as your sexlinked than yes you ll lose the auto sexing ability if you cross the F1 generation among them selves .a bared cockerel s over they sibling non bared . But there is a catch .if you select only the bared chooks from the F2 generation to work with and breed them together ,than you ll bred back the sex linked barring genes .all the cockerel chicks will be double barred . large white dots and all the pullets chicks will have a smaller white dot .

chooks man