Yellow Legs: Understanding the Genetics, Breeding and Judging Criteria

[LeslieDJoyce]

Working with the restoration project Delawares we want the "rich yellow" legs the breed calls for. It seems all the chicks hatch with super yellow/orange legs, and then some gradually shift in various directions. Greenish yellow, brownish yellow, faded yellow, and reddish yellow (cockerels, though I think I've seen some "salmon" type shanks on pullets this year). This seems to correlate to feather color on the rest of the bird, in such a way that the birds with the best feather color have the lightest legs.

So I have a ton of questions.

What does "rich yellow" look like? How much variety is allowed?

How do the genetics for "rich yellow" leg color work?

Are there ways to "test" a breeding bird for the genetics of "rich yellow?"

I'd really like to keep my project as pure as possible, so don't want to lose yellow legs.

Tips, tricks, advice, background info? Anyone?

 

[Yellow House Farm]

Rich yellow shanks are butter yellow. What you're seeing is common if there's been an outcross. Just select for the yellowest shanks possible. Going up the sided there may be some red veining/shading; that's fine.

PS: The Ancona has a little black ticking that the Delaware would/should not have. In this photo just focus on the quality of the yellow.

 

[LeslieDJoyce]

I found this great article that illustrates some shank colors.

https://scratchcradle.wordpress.com/2012/09/02/gms10-skin-and-shank-color/

I think it is difficult to distinguish between several of those shades, and the article does not explain the genetic variables involved. On a single bird, the leg color seems to shift quite a bit.

 

[LeslieDJoyce]

The re-created line of Delawares is only a few generations in ... I started with and F4 breeding trio last year. I know the parent stock was chosen very carefully, but it's still pretty close to the initial cross, and we're clearly still working on refining things.

 

[capayvalleychick]

Look what I found https://books.google.com/books?id=8...152#v=onepage&q=barred rock leg color&f=false

I was thinking about Joseph's comment about the color issues being from an outcross. Wondering how is that, when both BR and NH have rich yellow legs? When Don Nelson judged my pullet, he was perplexed at where the green tinge would have come from. This article may explain it.

 

[emenheiser]

Not a great deal known about the genetics of yellow legs, but most good breeders have been able to make considerable improvement just with basic selection and a conducive diet (green grass, marigold extract, or other sources of xanthophyll carotenoids). The trait is very environmental--there are many accounts of leg color drastically changing from white to yellow (or vice versa) by moving to other parts of the country. In the relatively new "projects" where the birds are more heterogeneous, leg color is less stable and less likely to breed true. Most of genetic information pertaining to leg color (beyond basic yellow vs. white skin color) deals with dermal melanin (duskiness). Since barring is a dermal melanin inhibitor, the Delaware has less of a problem with duskiness than other non-barred, yellow-legged varieties.

In my opinion, the key thing to keep in mind when evaluating leg color (aside from providing the right diet) is that few if any birds maintain bright yellow legs throughout their entire life. For example, it is expected for hens in lay to have faded shanks. Some chicks start out almost white-shanked and yellow up late in their first year of life. Some hatch with a greenish cast that is all but gone by 16 weeks. And there are a ton of other variations, depending on strain. Pick the age at which you want to assess leg color, and don't cull for it until then.

 

[capayvalleychick]

In the relatively new "projects" where the birds are more heterogeneous, leg color is less stable and less likely to breed true. Most of genetic information pertaining to leg color (beyond basic yellow vs. white skin color) deals with dermal melanin (duskiness). Since barring is a dermal melanin inhibitor, the Delaware has less of a problem with duskiness than other non-barred, yellow-legged varieties.

There are only a few of us with this strain of Delawares. The Barred Rocks used were from Frank Reese. The New Hampshires were German line. So, a new strain using old strains. I ended up with just a few F4s for breeding. The F5s all lacked proper leg color. They are either almost white or greenish pale yellow.
I don't want to cross in another strain, so I got a male from another breeder with this strain. He has better dark yellow legs. The offspring were looking pale but some are now becoming more yellow.

I'm wondering what I can do, if I don't have rich yellow in my breeding group and don't want to line cross? Is it possible to get rich yellow by simply selecting the most yellow each season? Or are they missing something?

 

[LeslieDJoyce]

There are only a few of us with this strain of Delawares. The Barred Rocks used were from Frank Reese. The New Hampshires were German line. So, a new strain using old strains. I ended up with just a few F4s for breeding. The F5s all lacked proper leg color. They are either almost white or greenish pale yellow.
I don't want to cross in another strain, so I got a male from another breeder with this strain. He has better dark yellow legs. The offspring were looking pale but some are now becoming more yellow.

I'm wondering what I can do, if I don't have rich yellow in my breeding group and don't want to line cross? Is it possible to get rich yellow by simply selecting the most yellow each season? Or are they missing something?

TOTALLY agree about not wanting to cross in another line at this point. I strongly believe doing that would just introduce more problems to "breed out" of the line.

Not a great deal known about the genetics of yellow legs, but most good breeders have been able to make considerable improvement just with basic selection and a conducive diet (green grass, marigold extract, or other sources of xanthophyll carotenoids). The trait is very environmental--there are many accounts of leg color drastically changing from white to yellow (or vice versa) by moving to other parts of the country. In the relatively new "projects" where the birds are more heterogeneous, leg color is less stable and less likely to breed true. Most of genetic information pertaining to leg color (beyond basic yellow vs. white skin color) deals with dermal melanin (duskiness). Since barring is a dermal melanin inhibitor, the Delaware has less of a problem with duskiness than other non-barred, yellow-legged varieties.

In my opinion, the key thing to keep in mind when evaluating leg color (aside from providing the right diet) is that few if any birds maintain bright yellow legs throughout their entire life. For example, it is expected for hens in lay to have faded shanks. Some chicks start out almost white-shanked and yellow up late in their first year of life. Some hatch with a greenish cast that is all but gone by 16 weeks. And there are a ton of other variations, depending on strain. Pick the age at which you want to assess leg color, and don't cull for it until then.

I think this is great advice. Though last year I didn't consider leg color much at all ... too many other things to worry about. We just really don't want to back ourselves into a corner here. There are so few of us working with this line that we don't have many other breeders to pull from if we lose something important in our local flock.

 

[Yellow House Farm]

At what age are they coming yellow in the shank? 4 or 5 weeks?

 

[capayvalleychick]

At what age are they coming yellow in the shank? 4 or 5 weeks?

The ones that I have this year that are changing to yellow are about 10 weeks old.