Developing auto sexing breeds.

[houndit]

I was wondering if anyone has any information to share on the subject. Probably the most popular Auto sexing breed is the Pilgrim Goose. There are others like the Cottonpatch Goose and the Legbar chicken. I have read about creating sex linked breeds. They are different. You cross a golden rooster and a silver hen Like a Rhode Island Red over a Rhode Island White hen. The chicks are color sexable when they hatch. This trait however does not carry on. So when the Pilgrim Goose was developed what did they do. Do you take for instance a Embden and cross it with as Toulouse? If you were doing this with chickens. Lets say we went ahead and Crossed our Rhode Island Red and our Rhode Island White. What next? These chicks are color sexable. Do we cross them again? With your original parent stock. Lets go back to Toulouse and Embden geese for example. Would we cross our male Embden and the female Toulouse. Then do we take only White males and dark females for the second breeding? I guess my main question is how do you get the gene that makes a difference in color when they hatch? If anyone has any information or a suggested website I would appreciate the input. I hope I managed to get my point across.

 

[Rootball]

Not sure about Developing, but here is something a few people know

the book "Bantam Chickens" by Fred P. Jeffery. page 170 states "Somes(1971) points out that the buff brahma is an auto sexing breed--93 percent accuracy in differintiating males from females at hatching time. All chicks are black on back and head. The male is clear cream-yellow on the upper surface of wings, sides of head, and belly. The female is smokey Gray in these areas."

This works on some other colors of brahma as well (dark and partidge) and I have no experience, but my guess is that any other breed with the same color genetics would be the same, ie. any buff Colombian breed.

Once you get used to looking for the difference it is not hard to see.

 

[blackdotte]

You are confusing sex-linked breeding with Autosexing breeds. Two totally different scenarios.
David

 

[Krys109uk]

Grey/white autosexing breeds of geese, such as Pilgrim, West of England & Shetland, came about long before anyone knew about genetics. Grey autosexing geese are mentioned in texts dating back to at least Tudor times & they were taken around the world by settlers. I don't know the genes involved, I'm not sure to what extent they have been studied. They've clearly not been as well researched as chickens.

The autosexing breds of chicken were developed by Prof.Punnet & others from Cambridge University in the first part of the 20thC & are based on sex linked barring & the way it shows on non black birds. They are easy to make.

 

[houndit]

Quote:
I know the difference. I was trying to compare them. The sexlinked birds will not carry on. The autosexing will. Sorry I confused you. You say that the autosexing chickens were developed as a sexlinked breed? What do you mean?

 

[blackdotte]

"You say that the autosexing chickens were developed as a sexlinked breed?"
No you must have misread or misunderstood. Sex linked chicks are the terminal result from the mating of two different birds ie Gold cock over silver hens (gold pullets & silver/gold split males) or unbarred males over barred hens (black pullets & barred males).
Autosexing breeds are breeds developed to breed true but provide a difference in the hatch down to enable sexing, although both are barred.
David

 

[Recla Ranch]

Houndit - Did you ever have any luck regarding the autosex breeds? I found a really great resource regarding the actual "recipe" for the Cream Legbars. It's quite complex, but clearly represents how they managed to maintain the autosexing. I've done considerable research trying to get some of these birds, but of course international shipping is near impossible. We may try our hand at breeding, but it looks like it'll take at least five generations to make it happen. Let me know if you found anything else out. Thanks!

(You can't link directly to the page, you have to go through their main website

http://www.legbarsofbroadway.co.uk/

Click on Main Site, then click on Cream Legbar in the Breed Info section on the left side of the page. Click "next" on the purple part of the page and you should get their origin.

 

[Krys109uk]

http://www.autosexing.co.uk/

Autosexing breeds are easy to make. What do you want to know about making them?