Feather sexing

[John Jordan]

Can the Ameraucana chicks be feather sexed and if so when is the best time to do it?

[Don]

John,  I have never tried to feather sex chicks.  Its much easier to do so when they are growing their adult feathers.  But you have to feed them for a season which is what most people are trying to avoid.  There are a few colors that you can make reasonably reliable selections based on coloration of young, silver (day olds) and wheaten (after a number of weeks).  There have been several discussions on the forum with others thoughts on the topic.  Search the topic for a list of posts.  These might give you some insights into the genetics behind the practice with chicks of different backgrounds.   Good Luck!     

[Cesar “CJ”]

Can the Ameraucana chicks be feather sexed and if so when is the best time to do it?

Feather sexing chicks can be accomplished by crossing males that are homozygous for rapid feather growth or carry two rapid feather growth alleles ( k+/k+) with females that are hemizygous or carry only one slow feather growth allele ( K/_W).

The female parent contributes a dominant gene for slow feather growth (K) to all the male offspring while the female offspring will inherit only one rapid feather growth allele ( k+)  from the father. This cross produces males that have slow feather growth (K/k+) and females that have rapid feather growth (k+/_W).

So the sire line must be bred to keep the fast growing feather genes and the dam must be bred to have the slow growing feather gene. This can only be accomplish by keeping two seperate lines to then combine them to feather sex. After the first generation it will not work.

[Susan Mouw]

Feather sexing chicks can be accomplished by crossing males that are homozygous for rapid feather growth or carry two rapid feather growth alleles ( k+/k+) with females that are hemizygous or carry only one slow feather growth allele ( K/_W).

Hi Cesar

I think you might have meant "heterozygous" here, rather than "hemizygous". Heterozygous means that both copies of the chromosome are present (one for the each parent), but the alleles are different (eg, K or W). Hemizygousity means that only one copy of the chromosome is present and the other is missing, which would not be a normal occurrence.  Homozygous is, as you stated, where both copies of the chromosome are present and the alleles match.

Hope this helps.

[Cesar “CJ”]

Feather sexing chicks can be accomplished by crossing males that are homozygous for rapid feather growth or carry two rapid feather growth alleles ( k+/k+) with females that are hemizygous or carry only one slow feather growth allele ( K/_W).

Hi Cesar

I think you might have meant "heterozygous" here, rather than "hemizygous". Heterozygous means that both copies of the chromosome are present (one for the each parent), but the alleles are different (eg, K or W). Hemizygousity means that only one copy of the chromosome is present and the other is missing, which would not be a normal occurrence.  Homozygous is, as you stated, where both copies of the chromosome are present and the alleles match.

Hope this helps.

Susan I believe since its a sexlink trait, which means K or k+ is only found in the Z chromosome . This means females wouldnt have both copies of the gene, just one copy of the K or k+ gene. So I believe "hemizygous" is the proper term to use

[Susan Mouw]

<face to palm>
Cesar, you are absolutely correct! My apologies.