trying to understand sex-linked genetics

[pysankigirl]

so is the silver-grey (diluting) gene one that can be used to create sex-linked chicks? for example...what would happen if I bred my SG dorking roo to welsummer hens?

just curious

 

[nicalandia]

so is the silver-grey (diluting) gene one that can be used to create sex-linked chicks? for example...what would happen if I bred my SG dorking roo to welsummer hens?

just curious

the correct name for the gene you are talking about its, Dominant Sex linked Silver(S) Silver Grey Dorking roosters have two copies of that gene(S/S) SG dorking hens can only have one copy(S/-) because the sex linked gene is located on the Z chromosome and hens only have one copy of it(ZW, the W gene is as usless as our human Y chromosome) roosters have two copies of the Z chromosome..

so if you want sex links you need to do the cross the other way around, Welsummer rooster to a SG dorking hens will give you gold based hens and Golden based roosters.

 

[nicalandia]

an issue you may find is to sex them at hatch, both have what is called "Chipmunk" Chick down color or Wildtype e+ genetically speaking and its very hard to distinguish gold chipmunk based chicks and silver chipmunk based chicks...

here is the welsummer chicks
Quote:

and here Silver Dorking chicks


Quote:

is not as clear cut as Red Sexlinks(Wheaten eWh based)


source http://www.cacklehatchery.com/redsexlink.html

 

[Henk69]

so if you want sex links you need to do the cross the other way around, Welsummer rooster to a SG dorking hens will give you gold based hens and Golden based roosters.

This must be confusing to a newby.
gold = s+/s+ males s+/- females
golden means the same as gold in english, but in chicken fancy it means heterozygous silver S/s+, which looks largely silverish but less white, more creamy/yellowish.

 

[pysankigirl]

darn...I only have a SG dorking Roo and a Barnevelder roo.
So would he Barnevelder Roo over the SG Dorking females work?

I am acually pretty good at sexing my Dorkings at hatch. maybe I should just stick with them!

 

[nicalandia]

This must be confusing to a newby.
gold = s+/s+ males s+/- females
golden means the same as gold in english, but in chicken fancy it means heterozygous silver S/s+, which looks largely silverish but less white, more creamy/yellowish.

henk have you hatch light brown and silver duckwing dutch at the same time?, how hard is to distinguish silver chipmunk and gold chipmunk chickd down on none red enhanced birds like dutch? I would guess the gold chicks would be just a bit darker but its always hard for me to tell them apart, its not an easy task sexing them(s+/- females from S/s+ males)

 

[nicalandia]

darn...I only have a SG dorking Roo and a Barnevelder roo.
So would he Barnevelder Roo over the SG Dorking females work?

it will work genetically, BUT again its hard to distinguish between silver wildtype chick down and gold wildtype chick down..

silver wildtype chick down should look lighter and gold chick down should look darker

can you tell the difference here?

Quote:
I think Golden roosters(Heterozygous for Silver S/s+) could look more like silvers but I just havent seen one yet

 

[catdaddyfro]

Illustration 2

Some crosses using silver females and gold males produce offspring that can not easily be separated into groups of male chicks or female chicks. It is important that the breeder choose the correct breeds to use in making a red sex linked cross.

As a general rule, do not use autosomal barred birds ( Campine, Fayoumi, etc) or spangled birds ( Appenzeller, Hamburg, etc.) and laced Polish ( laced tail and single lacing). These birds carry the birchen allele which will not produce the down colors needed in a red sex linked cross.

The author carried out a red sex-linked cross between a silver Appenzeller Spitzhauben female and a Rhode Island Red male. The only way you could tell the difference between the male and female chicks was by a small amount of reddish or whitish color on the chin. On some chicks, you could not distinguish the difference between the gold and white on the chin. See Illustration 3 The back of the chick in illustration 3 is black; the black down is covering the reddish or white down making it impossible to determine the sex of the chick.

Not my quote this is from tadkersons sex link thread FYI

 

[nicalandia]

Illustration 2

I wonder if Golden Males will look intermediate between gold and silver as Silver is not completely dominant over gold...

 

[nicalandia]

another issue is that you just cant cross some gold based wheaten breeds like Wheaten Old english game and silver based wheaten breeds like Faverolle and expect to obtain sex links, even if both breeds carry red enhancers(to enhance gold chick down) both of their chick down is very very pale making them impossible to sex...


Wheaten Old English Game chicks


salmon faverolle chicks



sexing these Sexlinks(Wheaten OEG roo over Salmon Faverolle Hen) would be a nightmare...