Sex- linked Information

The last two years I have experimented with sex-linking birds

Year 1 Barnevelder Male on Columbian wyandotte females
Year 2 Welsummer Male on Columbian Wyandotte females and on Barred Rock. The welsummer Barred Rock cross was to develop Welbars.

Both years were successful and I found very interesting.

This year I was going to try a Welsummer Male on White Leghorn females just for fun but read in Tim's first note about genetics that you should not use a white leghorn. Curious as to why you cannot use a white leghorn for sex-linked birds?

Leghorn are dominant white . Chicks will be white with a few colored specks . How will you see barring on a white chick ?
 
 
Not really what I meant... Trying to sex my day-old chicks



As farmerchef stated, they are "red sex links" so the red or reddish chicks are pullets and the yellow chicks are cockerels. This is true for all red sex links, though the patterns and shades may vary depending on the parent breeds. There is no sex link cross where the males are red and the females yellow.

I realize what you are saying, but this comment is too general relative to all breeds.
I breed purebred and created autosexed birds. These aren't sex linked, they are autosexed, but similar genetics apply.
Sexing chicks... there are more genes involved than just barring. The Co gene pair and the e allele play a big part not only in the color of the chick down, but also the feathering color. I won't even get into the genes that effect color "pattern".
The Co gene can create or hide a lot of black (the appearance of black in adult feathering is just one Co side effect), so to avoid black, or to assure it, you need make sure you Co pair is correct. The e allele effects chick down. For example, wheaten vs wildtype. If a chick is eWh/eWh, then yes the males could be yellow. But if you are dealing with wildtype alleles, e+/e+, then male chicks could be very dark red.
Knowing your foundation gene pairs is critical in determining expected outcome percentages. And because many breeds of poultry are truly not 100% purebred in their genotype, but their phenotype is correct, then test breeding to assure genotype is frequently necessary.
This is a sex linked male.
400
 
This year I was going to try a Welsummer Male on White Leghorn females just for fun but read in Tim's first note about genetics that you should not use a white leghorn.  Curious as to why you cannot use a white leghorn for sex-linked birds?


There are two things you need to make a sex link. You need the parents set up right genetically and you need to be able to see the effect in the chick. You can do it with leg color or fast-feathering but I think you are talking about down color with the White Leghorn.

There are two ways to get a solid white chicken like a white leghorn. You could have pure recessive white, which will hide anything so you don’t know what is under it. Could be anything. Some White Rocks have silver hiding under the recessive white so they can be used to make red sex links. Some don’t have silver or have something else hiding under that white that will keep you from seeing the sex link in the down. That’s why White Rocks. Rhode Island Whites, and other solid white chickens based on recessive white are not a good choice for sex links unless you know how they are put together color-wise.

You can have dominant white on extended black, which is probably what the white leghorn is. The white leghorn may or may not have silver, required for a red sex link. The leghorn may or may not have barred, required for a black sex link. A lot of white leghorns do have barring hiding under the white. It doesn’t matter what is hiding under the dominant white on an extended black base. You can’t see it in the down. Split dominant white on split extended black still gives you a solid white chicken with yellow down.

I don’t know what effect dominant white has on down color with Birchen, Wheaten, Duckwing, or Partridge. You can have different colored feathers on these patterns with adult birds and dominant white, but I don’t know if you will see it on the down. If an adult red sex link has a white tail, it probably has dominant white in it.
 
I too have auto sexed birds. Welsummers and cream legbars.
I believe in keeping lines pure but I just like to experiment for my own knowledge.


My experiment with the Barnevelders and Welsummers on the Columbians females gave me females that were red and males that were a black of some sorts. With the Welsummer/Columbian I picked up a darker egg which I expected but I also picked up larger egg size. Since I am not a genetic expert I was wondering if you used a Welsummer male on commercial white leghorn females if you would get the same kind of colored chick as you do Rhode Island Red male on White females.

I am trying to pick up egg size on one of my breeds. I try to hatch from the largest of the eggs collected. Is that how you increase size? Is the male the controller of egg size or is the female? Egg color I would think comes from the male just by my Welsummer/Columbian trial.

Thanks for the teaching moments of previous post I really appreciate it.
 
I have a SQ NH cock in a pen with two SQ NH pullets and BQ Del and Dorkings. The SL results are fabulous big burly chicks that grow into really prolific layers/meat birds..perfect dual purpose cross in my book is the NH over Dorking.
The last two years I have experimented with sex-linking birds

Year 1 Barnevelder Male on Columbian wyandotte females
Year 2 Welsummer Male on Columbian Wyandotte females and on Barred Rock. The welsummer Barred Rock cross was to develop Welbars.

Both years were successful and I found very interesting.

This year I was going to try a Welsummer Male on White Leghorn females just for fun but read in Tim's first note about genetics that you should not use a white leghorn. Curious as to why you cannot use a white leghorn for sex-linked birds?
 
In simplistic terms, a rooster gives a gene from every gene pair he has to all his offspring, boys and girls. A hen gives a copy of one of the genes at every location on the chromosome to her sons, but does not give the sex-linked genes to her daughters. That’s why the hen determines the sex even before the egg is fertilized. That’s the basis for sex linked.

Nothing is ever straightforward with chicken genetics, there are always exceptions to practically anything. But in general, this means the rooster has as much and in some cases more influence than the hen in everything.

Egg shell color is a good example. There are several different genes that determine egg shell color, some dominant and some recessive. If the egg is brown, what shade of brown depends on which genes are present and if they are dominant or recessive. The hen and rooster both contribute to that. But one of those genes is sex linked. If he has it the rooster can give it to his daughters and sons, but if the hen has it she cannot give it to her daughters, only her sons. So if the gene is present the rooster might have more influence on egg shell color than the hen, but if the gene is not present, they contribute equally.

I don’t know of any sex linked gene related to the size of an egg, so the hen and rooster probably both contribute equally to that. But a rooster does not lay eggs. How do you know what he is contributing? If you know what egg he hatched out of and even better what size eggs his parents hatched out of you have some clues as to what he might have, but you don’t know for sure. So the best way to increase the size of the eggs your flock lays is to save your breeding roosters from the ones that hatched from large eggs and pay attention to the size egg the hen lays that you breed him to.

Who controls eye color in a human, the father or the mother? Both, depending on what genetics they contribute and the genetic laws of dominant and recessive. The same is true for egg shell color or egg size, both depending on the genetic laws and what they contribute.
 

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