Genetics Qs- sex link, egg color

[HomesteadNowhere]

I'm doing a breeding experiment and wanting to make sure I'm understanding things correctly.

Sex link chicks only happen with certain crosses? So it only works for the first crossbreed offspring?
Is there true breeding sex links? Is that color/pattern specific or genetic specific?

I have brown egg laying breeds. I'm considering if I were to end up with a separate egg laying flock it would be fun to breed for green eggs.
Is this just as simple as getting some roosters of a blue egg breed? Is there a best breed for that?
Once I have a bunch of offspring could I then just keep breeding the best ones and keep producing chickens that lay green eggs?
What about breeding back to brown egg roo or to blue egg roo? I've seen a chart of this but wasn't sure the accuracy.

Is there a place online with a somewhat simplified list of which traits are carried by/ passed to/ sex linked/ etc? Picking up bits in many threads is a little confusing.

Thanks!

 

[The Moonshiner]

Ya only certain crosses make sex links and it is specific to which one has to be the rooster and which the hen. Ya they are one and done.
For something to breed sexable chicks generation after generation you need to create something referred to as autosexing.
Legbars are one of the best known autosexing breeds. They are blue egg layers so they would be great for your green egg layer project.
To be autosexing the best bet is a duckwing (wildtype) pattern with barring added.
Bielefelder are a autosexing breed that lay brown eggs so uses those two breeds will produce autosexing green egg layers in the first generation.
Other breeds that can be used but need the barring put in are Welsummers and brown Leghorns.
Creating a flock of green egg laying birds isn't hard but creating a flock that will continuously produce green eggers isn't as easy. To do that all your birds will need to carry two genes for blue eggs. Crossing a blue egger like the Legbar with a brown egger will produce birds with only one blue egg gene so half their offspring will not receive the needed gene.
You'll have to breed further to get the second gene in there and it will take raising birds to maturity then test breeding them and raising their offspring to laying age to see if you have one or two copies of the gene.
Thats the short answer and a place to start.

 

[Amer]

Ya only certain crosses make sex links and it is specific to which one has to be the rooster and which the hen. Ya they are one and done.
For something to breed sexable chicks generation after generation you need to create something referred to as autosexing.
Legbars are one of the best known autosexing breeds. They are blue egg layers so they would be great for your green egg layer project.
To be autosexing the best bet is a duckwing (wildtype) pattern with barring added.
Bielefelder are a autosexing breed that lay brown eggs so uses those two breeds will produce autosexing green egg layers in the first generation.
Other breeds that can be used but need the barring put in are Welsummers and brown Leghorns.
Creating a flock of green egg laying birds isn't hard but creating a flock that will continuously produce green eggers isn't as easy. To do that all your birds will need to carry two genes for blue eggs. Crossing a blue egger like the Legbar with a brown egger will produce birds with only one blue egg gene so half their offspring will not receive the needed gene.
You'll have to breed further to get the second gene in there and it will take raising birds to maturity then test breeding them and raising their offspring to laying age to see if you have one or two copies of the gene.
Thats the short answer and a place to start.

Since that is done, I'll just list the common sex-linked mutations and whether they are dominant or recessive.

Silver is incompletely dominant.
Barring is incompletely dominant.
Chocolate is recessive.
Dermal melanin inhibitor is dominant.
Slow feathering is dominant.

 

[DarJones]

and brown Leghorns.

and keep in mind that bringing in a breed means bringing in a boat load of recessive genes such as penciling/partridge. Brown Leghorns have the penciling gene mostly hidden behind the brown and red feather colors. It takes years to breed penciling out once it is in a flock.

 

[The Moonshiner]

and keep in mind that bringing in a breed means bringing in a boat load of recessive genes such as penciling/partridge. Brown Leghorns have the penciling gene mostly hidden behind the brown and red feather colors. It takes years to breed penciling out once it is in a flock.

What would need breed out of a brown leghorn if they were used to create an autosexing cross?

 

[nicalandia]

What would need breed out of a brown leghorn if they were used to create an autosexing cross?

None that would hinder autosexing, There is absolutely no gene in brown leghorn that would hace any detrimental effect on Autosexing trait

 

[The Moonshiner]

None that would hinder autosexing, There is absolutely no gene in brown leghorn that would hace any detrimental effect on Autosexing trait

Ya I've used them without issue so wasn't sure what they were thinking.

 

[DarJones]

Each breed has recessives for feather color, egg color, body type, leg and skin color, and other traits. When you combine two fairly stable breeding lines, those recessives sort out and often become visible. The result is like crossing Silver Laced Wyandotte with Brown Leghorn and getting a yellow hen with speckles in the F3 (yes it happened). Add to this by crossing in 2 or 3 additional breeds and the number of variations becomes very high.

My reason for using Brown Leghorn as an example is because they carry an unusually high number of recessives. A few I've seen are yellow feathers, orange brown feathers, mahogany red, penciling/partridge, puff feathers near the tail, rumpless, and weak chick legs. All of these were easy to breed out except penciling/partridge. It is going to take at least 3 more generations to get rid of it.

Silver Laced Wyandottes have relatively few recessives mostly associated with body and head structure and a few affecting feathers. Melanotic must cover a bunch of things that would otherwise be visible.

While not directly related to setting up an autosexing cross, it is related to the egg color genetics. The porphyrin biopath is going to get whacked by breeding with Legbars in your example. The result may still be acceptable as the eggs will range from white to blue tan/brown and green. This won't happen in the F1, will will in the F2.

 

[The Moonshiner]

So if all these breeds carry all these recessive genes why don't they show up constantly when breeding within the breed?
If I cross two brown Leghorns that both carry so many recessive genes wouldn't a lot of the offspring by chance get some from both parents and then express them?
I can't follow this logic.

 

[nicalandia]

I think Someone is grasping at straws trying to prove a point that is Irrelevant for Autosexing traits