Variability in Chick Down of Black Chicks - Genetic Clues?

[AUChickenGal]

This is purely a curiosity/academic question, as it will be months before I can begin to have solid answers, but I wondered if anyone here might have insight.

I have two chicks who hatched yesterday from Favaucana (yes, I realize that’s just a fancy mixed breed) eggs ordered from My Pet Chicken. The eggs came from a breeder in North Carolina. I was told the eggs could/would be an assortment from a BBS and/or a wheaten/blue wheaten/splash wheaten flock. Clearly, I “lost” the lottery and ended up with two black chicks from the BBS flock.

Now, MPC writes on their website that the Favaucana chicks they sell are F1, but all the eggs I received were sage green, so I know my chicks are AT LEAST F2. I know that means their genetics are even less predictable. I’m curious, though, whether their very different chick down offers any clues as to what they might be carrying.

The first chick has some gold mottling on his/her head and a gold/cream colored underbelly. This chick also has minimal, if any, muff/ beard feathering. The second chick has a much fluffier face and a white/silver underbelly.

Anybody here have insights to offer?

 

[Amer]

Doesn't yellow feathers mean it is gold based while white means silver based?
I could be wrong and am wondering this myself.

 

[AUChickenGal]

Doesn't yellow feathers mean it is gold based while white means silver based?
I could be wrong and am wondering this myself.

That was my first guess. Though I could have sworn I read somewhere that BBS Ameraucanas and Salmon Faverolles are both silver based, so, if that's the case, the gold chick is a bit of a head scratcher!

 

[nicalandia]

Doesn't yellow feathers mean it is gold based while white means silver based?
I could be wrong and am wondering this myself.

This is not the case in Extended Black chick down(at it's Extended Black Heterozygotes),

let me try to find the research paper where it says that any yellow parts of the Extended black chick down is due to melanocyte migration rather than if they are gold or silver based

 

[Amer]

This is not the case in Extended Black chick down(at it's Extended Black Heterozygotes),

let me try to find the research paper where it says that any yellow parts of the Extended black chick down is due to melanocyte migration rather than if they are gold or silver based

Thanks. I was wondering about that. Your point makes sense since my black d'Anvers seem gold based and I have white breasted chicks.

 

[nicalandia]

Okey, I found it, but it's actually a reference of a previous work, here is a scan of a page of the book "Poultry Breeding and Genetics" by R.D Crawford.

But as stated by the reference and on Page(79) of GENETIC CONTROL OF MELANIN PIGMENTATION IN THE FOWL J. Robert Smyth, Jr.(Same reference used by the book) https://www.poultryscience.org/docs/pba/1952-2003/1976/1976 Smyth.pdf

Excerpt from the research paper

"Fortunately, as it does in adult plumage, Co has a positive effect on silver-gold differentiation (Malone and Smyth, 1975b) 0 The addition of a single Co allele enhances this difference in the non-brown, lighter "ground" areas of the chick down. In combination with wheaten, gold intensity is increased by Co to the point where S-s+ sex-linked crosses provide readily identifiable sex identification."

What this means? That E/eWh, Co/co+, s+/- Mh/m+ females will have enhanced gold/red pigmentation as chicks(But only in combination of Heterozygous Wheaten, Columbian, Gold and in this case Mahogany boosting the effect), but E/E co+/co+ s+/- females can't be distinguished from E/E co+/co+, S/- females

Here check these black sex links chicks with such combination(RIR Rooster over Barred Rock Hen: Heterozygous Wheaten, Columbian, Mahogany and hemizygous gold), in this case, you could cover the males black head-spot and still notice the difference between the reddish/Brown face of the pullets and the yellow/white face of the males

In the case of the OP, the chicks are E/eWh, but lack Columbian so this will not apply, also since they are the cross of a Faverolle rooster(Wheaten based Silver) over Ameraucana hens, the F1 pullets will be Silver based so no chance of sexing them from the S/s+ males even if it was possible(not due to E/eWh co+/co+ combination)

 

[Amer]

Okey, I found it, but it's actually a reference of a previous work, here is a scan of a page of the book "Poultry Breeding and Genetics" by R.D Crawford.

View attachment 1781500

Thanks.

 

[nicalandia]

Thanks.

Updated the post with more info and references

 

[AUChickenGal]

Wow! Thank you, @nicalandia, for taking the time to put all that information together for me. I've always been fascinated with equine color genetics, and I thought THAT was complicated until I started studying chickens.

 

[nicalandia]

Wow! Thank you, @nicalandia, for taking the time to put all that information together for me. I've always been fascinated with equine color genetics, and I thought THAT was complicated until I started studying chickens.

Yes, Avian feather color genetics is substantially more complex than equine color genetics