Can someone tell me about the black pigmentation that silkies have? We have hatched 10 chicks from our now deceased silkie/sexlink rooster. The eggs came from sexlinks, aracaunas, and 3 silkie/sexlink hens (no idea who's eggs hatched). The 3 silkie/sexlink females had black skin like their silkie daddy but the silkie/sexlink roo had normal skin color and we now have 4 out of the 10 chicks that have black skin. There is no way we set 4 of the silkie/sexlink eggs so I'm assuming these chicks got the skin color from a recessive gene daddy had. Am I on track or totally lost here? I'd like to have larger black skined and fleshed fowl so would like to know if this pigmentation will carry on to the next generation. Thanks for putting up with my questions. Mina

Mina, the hypermelanic condition (dark skin) of the Silky breed is due to a dominant gene, Fm (fibromelanosis gene). There is considerable interaction between Fm and sex-linked melanin inhibitors. Examples are the combinations: Fm with id+ (id+ is wild-type dermal melanin or skin pigmentation) gives darkly pigmented skin, but Fm with Id (Id is a sex-linked mutation that inhibits dermal melanin) gives a lightly or 'faintly' pigmented skin that can even 'pass' for unpigmented. A 1987 study did not detect skin pigment in females with Fm and Id. Because the fibromelanosis gene, Fm, can be 'inhibited', it can go unnoticed in a bird and the way to tell is through breeding experiments.

Without more complete information, I can only guess that your rooster was Fm/fm+ (the '+' sign indicates the wild-type gene or allele and for chickens the wild-type is the Jungle Fowl) and maybe Id/id+ which would could give him an almost normal-looking skin. The dermal melanin inhibitor, Id, could have (probably did) come through the sex-link side of the roosters parentage. Then, because the fibromelanosis gene, Fm, and the dermal melanin inhibitor gene, Id, are inherited independently, some of his chicks would get the Fm gene (dark skin) without the dermal melanin inhibitor, Id. These should be your dark-skin chicks.

You could start a "lab book" and record your estimates of the genetics of your chicks and refine those guesses as future generations reveal more information. It's a lot of fun and pretty soon you will know a lot about the gene pool you have.

And, we have another example of why this is the "classroom". Mina, I am curious why you want the dark skinned larger chickens? Robb

As Leee states you need two genes to get the Silkie black skin: Dominant Fm and recessive sex-linked id+. Your hybrid rooster got the Fm and id+ from his Silkie dad, but he got the fm+ and Id from his sex-linked mom. So the rooster was Fmfm+ and Idid+ and had light skin due to dominant dermal melanin inhibitor (Id). If you cross this hybrid rooster to sex-linked hens 1/4 of the female chicks will have black skin (Fmfm+ id+W) and none of the male chicks would have black skin because all males would get the dominant Id from the hens. If the male was crossed to Ameraucana (fm+fm+ id+W) hens 1/4 of the male and female chicks would have black skin. Male chicks would be Fmfm+ id+id+ and females would be Fmfm+ id+W. The 3 Silkie/sex-linked hens are Fmfm+ id+W and their progeny will have 3/8 black skined female and 3/8 black skin males. This is because you can have two types of each type of black skined birds FmFm id+W and Fmfm+ id+W females and FmFm id+id+ and Fmfm+ id+id+ males.
_________FmId________Fmid+______fm+Id________fm+id+
Fmid+__FmFmIdid+__FmFmid+id+__Fmfm+Idid+__Fmfm+id+id+
FmW___FmFmIdW___FmFmid+W___Fmfm+IdW___Fmfm+id+W
fm+id+_Fmfm+Idid+_ Fmfm+id+id+_ fm+fm+Idid+_ fm+fm+id+id+
fm+W__Fmfm+IdW__Fmfm+id+W__fm+fm+IdW__fm+fm+id+W}

These are the expected genotypes from your hybrid male crossed to the hybrid black skined females. The first row is the genotype of the sperm produced by the rooster and the first side column is the genotypes of the eggs produced by the hens. The sperm and eggs can combine randomly to form the different genotypes that you see. The W chromosome doesn't have very many genes on it, but all females inherit it from their mothers. Females are ZW and males are ZZ in sex-chromosome composition. Any time a chick inherits the Id gene it does not have black skin if it does not inherit at least one Fm gene it cannot be black skined even if it has id+.

Your Ameraucana hens will produce only two types of eggs and the results would be the following:

FmId Fmid+ fm+Id fm+id+
fm+id+ Fmfm+Idid+ Fmfm+id+id+ fm+fm+Idid+ fm+fm+id+id+
fm+W Fmfm+IdW Fmfm+id+W fm+fm+IdW fm+fm+id+W

1/4 of the males and females would have black skin.

Your sex-linked hens would produce only two types of eggs and the results would be the following:

FmId Fmid+ fm+Id fm+id+
fm+Id Fmfm+IdId Fmfm+Idid+ fm+fm+IdId fm+fm+Idid+
fm+W Fmfm+IdW Fmfm+id+W fm+fm+IdW fm+fm+id+W

Only 1/4 of the females would have black skin.

PS the formating seems to get messed up and I'm not going to mess with it. If you cut and paste to a word processor and use courier you should see the Punnett squares.

Thank ya'll soo much! This helps a lot! Robb, basically we have a restaraunt that wants to buy black skinned/fleshed chickens from us but most of our silkies are tiny. The silkie/sexlink hens on the other hand were almost as big as their sexlink mamas and the chef was delighted with their size. Plus I find it hard to butcher a cute little silkie! Thanks again Lee and Rokimoto!

If you go in for artificial insemination you can cross a silkie to a broiler hen and all the daughters will be black skined and pretty hefty. It is hard to keep broiler hens in production because you have to feed restrict them.

If you keep the black skined roosters from the present crop of chicks you can get a higher frequency of black skined progeny by crossing them to Ameracanas or black skined crossbred females.

Thanks Rokimoto! I've always considered myself an adventurous and capable female but think I can do without the experience of artificially inseminating the hens! Think I'll keep one of the dark skinned roos instead :P