How would you go about breeding autosexing into a breed that doesn't have it?

[Cloverr39]

I'm trying to learn about what causes autosexing and how you would go about breeding it into a breed that doesn't have it.
What colors does it work on? How many generations would it take to breed it in? Is there a specific gene that causes it or is it multiple things combined?
Where I live the most commonly known autosexing breed is the cream legbar. If I ever did attempt to try breeding it in it would most likely be from cream legbars.

 

[Egghead_Jr]

Why would you create auto sexing when you have access to a breed, Cream Legbar, that already are auto sexing?

The Legbar took 15 years to create. Obviously much of that time was fixing the unique traits of the breed. But the auto sexing aspect still takes years to set.

 

[Cloverr39]

Why would you create auto sexing when you have access to a breed, Cream Legbar, that already are auto sexing?

The Legbar took 15 years to create. Obviously much of that time was fixing the unique traits of the breed. But the auto sexing aspect still takes years to set.

I was just wondering how it worked. I don't really need it, nor will I be creating an autosexing breed. I was however planning on starting to create a new breed in a couple years. Someone once said to me that it should have autosexing and while I don't think this project needs it I have been wondering how autosexing works purely our of curiosity.

 

[Amer]

Most autosexing breeds are duckwing with some form of barring. (Legbar, Welbar, Bielfelder, etc.) They can have different modifiers like silver, mahogany, lavender, and cream, even recessive white I am told (as in White Legbars), and still be autosexing.
There are a few with barring and some other color though, like Ancobars (barring and mottling) and Wybar (barring and silver lacing) I believe the Wybars were harder to sex, though, and if you put barring on a black tailed red (Rhodebar) you will get autosexing. I black tailed buffs may also have this trait, but I think they might be slightly more difficult to sex.

 

[phasianidae]

Sex linked barring and sex linked silver are two genes that I know of that can be used to create autosexing in chickens. Both work for this because they are located on the sex chromosomes, of which male chickens have two and females only one. That means if you have a line of chickens that has either silver or barring in a homozygous state, the males will have two doses and the females one dose. If everything works out right, this can allow for male chicks to show a visibly stronger expression of the gene in their down feathers. Barring is more fool proof and works on a range of color backrounds. Silver can work very reliably on a wild type e+ (duckwing) backround in some cases, and can probably work on other colors as well. Some lines of silver duckwing colored chickens reliably produce female chicks with darker color and eye stripes while the male chicks are lighter overall and lack any eye stripe.

I've thought about experimenting more with autosexing in the past but never have because I don't understand the sensation surrounding it nor the value of it apart from commercial use where male chicks will be discarded. I always need 50% males and females for my purposes so I have focused my interests on other areas. I am sure there is a lot more to discover though for someone who is interested.

 

[NatJ]

I'm trying to learn about what causes autosexing and how you would go about breeding it into a breed that doesn't have it.
What colors does it work on? How many generations would it take to breed it in? Is there a specific gene that causes it or is it multiple things combined?
Where I live the most commonly known autosexing breed is the cream legbar. If I ever did attempt to try breeding it in it would most likely be from cream legbars.

Most autosexing breeds are duckwing with some form of barring.

If you already have Cream Legbars, you could cross them to something else, then cross back to Legbars, and some of the birds in that second generation will have all the right traits to breed true for autosexing. So two generations is the minimum time. You might manage that in a single year, depending on what months you are able to raise chicks.

But if you do it in two generations like that, you've got birds that are 3/4 Legbar. So if you want other traits in your birds, you will almost certainly end up taking more generations to do it.

You could also cross Legbar x something, then breed those crossed chicks together, and if you hatch enough chicks you should be able to pick some correct ones from that second generation. There will be more wrong-colored ones that way, as compared with backcrossing to Legbar, but you might keep more of the other traits you want in the new breed you are creating.

 

[HaikuHeritageFarm]

I used a Legbar over mottled Houdans and we're getting a few different varieties of autosexing now that have the Houdan traits, now in the 3rd generation.

If some you're of wildtype already exists in the breed, just introduce barring. If barring exists, introduce wildtype, if barring exists, it would be most efficient to use an autosexing male over a hen that you're trying to introduce the color to... extended black is fairly safe. You'd get all black cuckoo f1, crossed together you would begin to see the wildtype chicks again, with and without barring. It takes a lot of hatching.