Vulture hock genetics

[Cloverr39]

I'm trying to breed out vulture hocks in my silkies, but trying to breed them into my new breed project. I thought actually knowing the genetics behind them would help.
I'm breeding a rooster with vulture hocks to hens without them. Would there be a 50/50 chance of the chicks having them or is it more complicated than that? And does breeding 2 birds that have them always result in chicks with vulture hocks?

 

[pipdzipdnreadytogo]

Vulture hocks are considered a recessive gene, but reportedly have some slight expression when heterozygous. Their expression is also tied to the expression of one of the leg feathering genes. In other words, a bird could have the gene for vulture hocks and not express it if they don't have the right leg feathering gene alongside them to do so. So as for whether vulture hocks to vulture hocks will always produce vulture hocks, it depends on if they're pure for that other leg feathering gene as well. And whether there would be any expression in the offspring in a vulture hocks to no-vulture-hocks cross, it likely also depends on the other genes at hand. I would not expect much of an expression in that cross, however.

Why are you trying to breed them out of your Silkies? Because of it being considered a disqualification (at least in the standard over here in the U.S.)? The interesting thing about that trait being a disqualification is that, at least here in the U.S., the breeds with the most profusely feathered legs actually have the genes for vulture hocks as well, filling out their leg feathering. So why is that considered a disqualification for some of those breeds? Near as I can tell, the intention of that being in the standard is to prevent birds in those breeds from having the actual appearance of having vulture hocks. Vulture hocks in d'Uccles, for example, are tightly pinched together, stiff, and apparent off the hock at a glance. In Silkies and Cochins, they're more spread and softly feathered, blending with the rest of the leg feathering. On top of that, Cochins and Silkies sit low to the ground relative to other breeds. If a line of Silkies becomes too leggy, or their hocks become too pinched instead of spread, then those hock feathers start to 'emerge' away from the rest of the leg feathering to become a distinct and apparent vulture hock off of the leg instead of a clump of feathers within the clump of feathers on the leg. That all said, this is only my two cents as a simple reader and researcher, and not as one who actually shows poultry. I also do not know what these breeds look like in Europe, nor what judges in your shows over there will disqualify or knock points off for.

Edited to finish a thought, whoops​

 

[Cloverr39]

Why are you trying to breed them out of your Silkies? Because of it being considered a disqualification (at least in the standard over here in the U.S.)? The interesting thing about that trait being a disqualification is that, at least here in the U.S., the breeds with the most profusely feathered legs actually have the genes for vulture hocks as well, filling out their leg feathering. So why is that considered a disqualification for some of those breeds? Near as I can tell, the intention of that being in the standard is to prevent birds in those breeds from having the actual appearance of having vulture hocks. Vulture hocks in d'Uccles, for example, are tightly pinched together, stiff, and apparent off the hock at a glance. In Silkies and Cochins, they're more spread and softly feathered, blending with the rest of the leg feathering. On top of that, Cochins and Silkies sit low to the ground relative to other breeds. If a line of Silkies becomes too leggy, or their hocks become too pinched instead of spread, then those hock feathers start to 'emerge' away from the rest of the leg feathering to become a distinct and apparent vulture hock off of the leg instead of a clump of feathers within the clump of feathers on the leg. That all said, this is only my two cents as a simple reader and researcher, and not as one who actually shows poultry. I also do not know what these breeds look like in Europe, nor what judges in your shows over there will disqualify or knock points off for.

So as long as it doesn't look like they have vulture hocks and it blends into their fluff it's okay for silkies to have them?

 

[pipdzipdnreadytogo]

In the U.S., at least from my understanding, yes. Bear in mind that my focus is Cochins, not Silkies, and again that I have no experience with the differences between U.S. and European standards for either breed, but I understand that they have very similar builds in show quality lines here in the U.S. Let me pull up a picture of one of my Cochins as an example. She has vulture hocks, you can feel them in the feathers on her legs because they are stiff like the wing feathers compared to the soft surrounding feathers, but they sort of blend into the rest of her fluff. Without them, she wouldn't look nearly as nicely rounded as she should for her breed.

The clump of feathers circled here is what the vulture hock gene is providing to her fluff, but in combination with the rest of her leg feathering, it doesn't stand out:

Ideally they'd be even less distinguishable from the rest of that fluff like with this hen:

Now just add dark skin and an overabundance of fluff on the head as well, and you've pretty much got a show quality Silkie.


I don't have great pictures of my poor quality Silkies to show it, but here is one of my roosters who is certainly too leggy, and the vulture hock stands out on him. From my understanding, that is what you're trying to avoid in show birds. But, of course, I would defer to anyone with more experience with the breed should they chime in on that.