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!

 

[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.

 

[sylviethecochin]

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?

I have no personal experience with chocolate, but I'm pretty sure it doesn't help with autosexing. Silver definitely doesn't. On the other hand, "Wildtype" (duckwing) of a good line is lighter on male chicks than it is on female chicks (See: Wellsummers, OEGs) which is probably why it was used for Legbars. I don't know if there are other genes that do this.

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?

Any colour dark enough to contrast the white spot will work. Black definitely will work (black sexlinks) Birchen should work. Wheaten won't work, almost certainly. Dark wheaten (with a Db modifier gene or two) will breed a dark enough chick that you should be able to see the spot. Especially if the chick also possesses mahogany genes (like dark RIRs. Not sure it it would work with New Hamps-- they're pretty light.)

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?

Splash or light blue definitely would not contrast the spot. I've seen Lavender chicks, and it seems unlikely, but you'd have to asks someone with actual experience. Other than genes that make the down too light to see, I'm not sure.

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

Db, as already said, enhances some colours and would help with barring.
Col... in my experience, its only effect on the chicks' down is to make them darker, so would probably help with barring.
Mel? Not sure.
Charcoal? no idea.
Mahogany makes red darker and would make the white barring spot stand out better. Not as well as it would against black, but better.
Dilute? No personal experience.
Cream ig wouldn't hurt anything since it only effects gold to make it a brassier colour. Cb= same thing, as far as I know.
Silver is sexlinked, obviously, but it just turns partridge chicks lighter in colour. It would depend what you're planning on doing with it, whether it would have an effect.

The only I genes I know are dominant white and black. I suspect you already know what those do.

 

[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.

 

[Notaneggspurt]

About half way down the page is a list of auto sexing breeds. Notice the "bar" in each of the names. You can do an individual search for each breed.
https://poultrykeeper.com/poultry-breeding/autosexing-poultry/

I think one of the most recent breeds would be the isbar.

 

[Notaneggspurt]

There is a good little post about 2/3 of the way down regarding the 55 flowery hen's genetics.
http://www.the-coop.org/forums/ubbthreads.php?ubb=showflat&Number=50678

 

[Notaneggspurt]

Finally found it:
https://scratchcradle.wordpress.com/2012/08/26/gms9-autosexing-recipe/

Your project idea reminded me of the last paragraph in the article.

 

[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.

 

[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.