Fibromelanism and crossbreeding

[CBMorgan]

I have two chicks from a pure Qaib Thaib black hen crossed with a Ayam Cemani x Svarthona roo, but honestly they look mostly Cemani/Svarthona to me at this point. They don't stand very upright and are a bit fluffy, but are still pretty young anyway, maybe 6-7 weeks old now.

One had dark grey down instead of black at 5-7 days old so the breeder supposed another cock got to the hen, but they both look pretty much identical now except the grey-downed chick has a tiny bit more white on him.

The black-downed chick is pretty much all black with the exception of two toenails (if I remember correctly) and some random tiny little splotches on the tips of her left side chest feathers and a bit of pink in the mouth. The grey-downed one is all black with a few white tipped primaries and four white toenails (again, if I remember correctly), bit of pink in the mouth again. I think both had a tiny bit of pink on the pads of the feet as well. Both have the very big black eyes and black skin, combs, etc.

It's a bit luck-of-the-draw what you are going to get in the chicks - how much of their appearance is inherited from dad vs mom. You can just keep the ones you like the looks of best as they grow older, but studying up on genetics would really help you out in the long run. This is a decently thorough article to start with if you know the basics of genetic inheritance: http://www.edelras.nl/chickengenetics/mutations1.html#gen_mut_elocus

 

[Alex_Zurago]

I have two chicks from a pure Qaib Thaib black hen crossed with a Ayam Cemani x Svarthona roo, but honestly they look mostly Cemani/Svarthona to me at this point. They don't stand very upright and are a bit fluffy, but are still pretty young anyway, maybe 6-7 weeks old now.

One had dark grey down instead of black at 5-7 days old so the breeder supposed another cock got to the hen, but they both look pretty much identical now except the grey-downed chick has a tiny bit more white on him.

The black-downed chick is pretty much all black with the exception of two toenails (if I remember correctly) and some random tiny little splotches on the tips of her left side chest feathers and a bit of pink in the mouth. The grey-downed one is all black with a few white tipped primaries and four white toenails (again, if I remember correctly), bit of pink in the mouth again. I think both had a tiny bit of pink on the pads of the feet as well. Both have the very big black eyes and black skin, combs, etc.

It's a bit luck-of-the-draw what you are going to get in the chicks - how much of their appearance is inherited from dad vs mom. You can just keep the ones you like the looks of best as they grow older, but studying up on genetics would really help you out in the long run. This is a decently thorough article to start with if you know the basics of genetic inheritance: http://www.edelras.nl/chickengenetics/mutations1.html#gen_mut_elocus

Is it any larger than a cemani?

 

[CBMorgan]

The two Svarthona chicks I have are a bit younger, so hard to compare. The extra feather makes them look a bit larger, but they are not any taller than our pure Thai birds of the same age. They also don't stand quite as erect, as I think I mentioned. They look more Cemani than Thai, but they have Thai feet, that back toe that they walk on the tip of instead of the feet being flat like other chickens, and they do stand more upright than a Cemani. Kind of about the carriage of a Sumatra I would say. If I have time to take some photos I'll post them.

 

[Alex_Zurago]

The two Svarthona chicks I have are a bit younger, so hard to compare. The extra feather makes them look a bit larger, but they are not any taller than our pure Thai birds of the same age. They also don't stand quite as erect, as I think I mentioned. They look more Cemani than Thai, but they have Thai feet, that back toe that they walk on the tip of instead of the feet being flat like other chickens, and they do stand more upright than a Cemani. Kind of about the carriage of a Sumatra I would say. If I have time to take some photos I'll post them.

I was rly moreso asking if they were taller than Cemani

 

[Alex_Zurago]

I was rly moreso asking if they were going to get taller than Cemanis since I'm unfamiliar with this other breed though I do know about Svart Honas. Having a taller breed would probably lessen the amount I have to cull

 

[Alex_Zurago]

I think you're dealing with two genes-- Fm and id+

Oops, it posted before I finished, so I'm editing to finish:

Fm is not sex linked, so it can come from either parent, and then you'd have to either cross F1s or backcross to the fibro parent.

id+ is needed to let the fibro show in the skin, and you can get that in a hen just by having a fibro father. Or you can cross an F1 rooster to his mother or his sister (any hen with id+) to get 50% of each gender showing id+.

How do you know if a bird has id+. Ive been thinking of using a fibro easter egger female to the other breeds male to get more eggs with the fibro gene. Would there be a way to make sure that it is not sex linked. Im not a fan of sex linked crosses I want all the birds to show fibromelanism.

 

[NatJ]

How do you know if a bird has id+.

Usually by looking at their legs.

A female has only one Z chromosome, so either she has it or she does not have it.

A male has two Z chromosomes. If he has id+/id+ then you can tell by looking.
But if he has Id/Id or Id/id+ you won't be able to tell which. (Because Id is dominant.)

Usually you recognize id+ because the bird has blue or green legs (sometimes called slate or willow). It gets more complicated when dealing with black chickens, because the genes that make black feathers can also make some black on the legs (example: Barred Rocks often have some black in the legs, even though they should be pure for id+)

Ive been thinking of using a fibro easter egger female to the other breeds male to get more eggs with the fibro gene.

That sounds like a good idea.

Would there be a way to make sure that it is not sex linked. Im not a fan of sex linked crosses I want all the birds to show fibromelanism.

If both parents are pure for the genes, then you can cross them in any direction you like, sex linked or not, and all the chicks will be pure for the genes too.

For the sexlinked id+, if the rooster is pure for it, his daughters will get one copy on their only Z chromosome (which is as pure as a female can get), and his sons will get one copy from him and one copy of whatever their mother had (Id or id+).

If the hen has id+ she will pass it to their sons (who will only show it if they also got it from their father), but she will not pass it to her daughters (they get a Z chromosome from their father and a W chromosome from their mother.)

 

[Alex_Zurago]

Usually by looking at their legs.

A female has only one Z chromosome, so either she has it or she does not have it.

A male has two Z chromosomes. If he has id+/id+ then you can tell by looking.
But if he has Id/Id or Id/id+ you won't be able to tell which. (Because Id is dominant.)

Usually you recognize id+ because the bird has blue or green legs (sometimes called slate or willow). It gets more complicated when dealing with black chickens, because the genes that make black feathers can also make some black on the legs (example: Barred Rocks often have some black in the legs, even though they should be pure for id+)


That sounds like a good idea.



If both parents are pure for the genes, then you can cross them in any direction you like, sex linked or not, and all the chicks will be pure for the genes too.

For the sexlinked id+, if the rooster is pure for it, his daughters will get one copy on their only Z chromosome (which is as pure as a female can get), and his sons will get one copy from him and one copy of whatever their mother had (Id or id+).

If the hen has id+ she will pass it to their sons (who will only show it if they also got it from their father), but she will not pass it to her daughters (they get a Z chromosome from their father and a W chromosome from their mother.)

I plan to do it with an Indio Gigante, so I suppose the plan is to purchase the largest fibro easter egger hen I can find with minimal to no leakage, and then see which ones of the F1's have slate colored legs and dark feathers, and then inbreed them until I get birds that are homozygous for fibro and id+?

 

[NatJ]

I plan to do it with an Indio Gigante, so I suppose the plan is to purchase the largest fibro easter egger hen I can find with minimal to no leakage, and then see which ones of the F1's have slate colored legs and dark feathers, and then inbreed them until I get birds that are homozygous for fibro and id+?

That sounds reasonable. I'm just not positive how much the black (feathers) will affect the leg color (making it hard to tell which ones actually have fibro and id+).

But choosing the darkest ones is a sensible way to select! That's how people did chicken breeding before they knew about the specific genes, and it does still work. Knowing the gentics just helps speed up the process sometimes.