Barred X Black ?

[RAREROO]

My question is when a Barred Rock roo is bred to a solid Black hen, I know the all the offspring will be Barred/Cuckoo, but will it be the normal looking sexlinked barring like Barred Rocks, or will it be really dark with only a faint indication of barring? Anyone have pics of a Barred X Black cross where the Barred one is the father?

 

[blackdotte]

Barred male,B/B X Black hen b+/- will give B/b+ males & B/- pullets. The cockerels will be as dark as the hens, and will not have the silvery head,neck & tail hackles of the B/B males.
David

 

[RAREROO]

OK thanks, So if I have a Dark Barred roo, is that homo. or het barring? and is there an advantage in useing dark barred roos instead of light barred roos in projects that need a barred roo?

 

[Sonoran Silkies]

Het barring. The advantage of using a hom barred male is that he will provide a copy of barring to all his offspring. A het. barred male will provide it to only half of his offspring, regardless of gender.

The barring will not be faint on a het roo, but will have the same appearance as a barred hen who can only carry one copy of the gene.

 

[RAREROO]

Quote:
So does this mean that half will be barred and half will be black.

What if I breed a het roo to het ( normal dark) hens? Will all of them be barred or only half of them too?

 

[Sonoran Silkies]

Quote:
So does this mean that half will be barred and half will be black.
yes
What if I breed a het roo to het ( normal dark) hens? Will all of them be barred or only half of them too?

You cannot have a het hen, which implies that she can carry two copies of the gene. For all sex-linked genes, a hen is hemizygous. She carries only one copy, which she passes to all her sons.

Mating a barred hen to a het barred roo will give approximately half of the resulting cockerels carrying two copies of B and the other half carrying one copy. About half the pullets will be barred and the other half will not. Here is the punnet square:

| B b
B | BB Bb
- | B- b-

 

[RAREROO]

So what about the barred roos that would be produced from a black roo on barred hens? These will be sexlinks but will they also be het. barred or a light silver barred like sexlink roos produced from a RIR X Barred mating. And would the barring from a Black roo Barred hen mating be less definite than the the barring from the vise versa mating? Will the Barred roo from a Black roo X Barred hen, produce all barred chicks when mated to a barred hen? Also please explain it in layman's terms, I'm not familiar with the abrevitations for certain genes. Thanks for your help.

 

[Sonoran Silkies]

The barring allele is indicated with B; the non-barring allele with b+; when referring to a sex-linked gene, a - is used to indicate that lack of a locus for it in the female.

The quality of the barring does not depend on which parent it was inherited from but upon whether the bird carries one or two copies, and the presence or absence of the slow feathering gene. If present the barring will be sharper/crisper. If absent it will be fuzzier. This is not sex-linked and is completely independent of the barring gene.

A hen carries only one copy of all sex-linked gene; her sex chromosome is shorter than the sex chromosome of males.

Incompletely dominant genes such as barring have an intermediate appearance when present in one copy versus two or none. Thus a barred bird carrying two copies of the gene appears significantly lighter than a barred bird carrying one copy. Thus a cock with one copy of the gene has the same appearance in his barring as a hen. A cock carrying two copies appears lighter. A cock with one copy actually has one copy of barred and one copy of not-barred. About half his progeny will receive one of these and the other half the other. This is not determined by the offspring's gender.

On the other hand, a hen passes her W chromosome to her daughters; the genes carried on her Z chromosome are passed to her sons. (Not technically accurate, but it is an easy way to explain and understand.) If she is barred, all her sons will receive that gene from her. If she is not barred, they will receive that gene.

Black roo over barred hen is sex-linked. Black daughters and sons with one copy of barring.

Barred roo (two copies) over black hen is not sex-linked. All offspring will have one copy of barring.

Barred roo (one copy) over black hen is also not sex-linked. About half the offspring will be barred and about half will not.

Barred roo (two copies) over barred hen is sex-linked. Males carry two copies; females one, so males appear lighter.

Barred roo (one copy) over barred hen is not sex-linked--exactly. All males will receive at least one copy (from mama); about half of the chicks, regardless of gender, will receive a copy of barring from papa; about half will not. So, some males will have two copies, some males will have one copy, some females will have one copy and some will be black.