Cuckoo / Barred project question

[Dipsy Doodle Doo]

Hi! I copied from this thread about Barring gene.

Usually a purebred barred male might be expected to be carrying two barring genes. So if he is crossed with a non barred hen then all of his offspring, whichever gender, would inherit one barring gene from him. From the mother the male offspring would also inherit & non barred gene on their Z chromosome & the female offspring would inherit a w.

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A female is either B- (barred) or b- (not barred).

A male may be BB (barred), Bb (barred), bB (barred) or bb (not barred).

A male that is BB when mated with a female that is b- will produce 100% barred offspring; males will be Bb and females B-.

A male that is Bb (or bB) when mated with a female that is b- will produce 50% barred offspring and 50% non-barred offspring; males will be either Bb or bb and females will be either B- or b- all with equal likelihood.

I know this Cochin guy is Bb:

As is this Serama:

I have not test mated this guy, but what do you think? BB or Bb?

If he is Bb, and I mate him with a B hen, then their offspring will all be BB or B?
THEN, can I take a barred male from that cross and mate back to solid hens and get all barred birds (BB, Bb, and B) again?

Can you tell without test mating whether a roo is BB or Bb?
Will there be an obvious difference in the barring?
Thanks!

Lisa​

 

[Henk69]

Quote:
He looks B/b+. B/B roosters look lighter.

1st cross: B/b+ * B/- => B/B and B/b+ males, B/- and b+/- females
25% solid females

2nd cross: B/B * b+/- => B/b+ males, B/- females
all barred

 

[Dipsy Doodle Doo]

Hi Henk! Thanks! I'm sorry to be dense, but I have more questions.
Is there a difference between Bb (barred males)and bB (barred males) or was that a typo in the post I copied?
I don't understand the + / -, but I think I have a better grasp now.

1st cross: B/b+ * B/- => B/B and B/b+ males, B/- and b+/- females
25% solid females

I just hatched more chicks from the cuckoo green-egger pen and 2 didn't have a head-spot
--- just figured I'd mismarked a couple of eggs.
I *thought* all the chicks from the cross would have been barred. Those would be from the '25% solid girls' and not mis-marked eggs (good for that, but this makes me have to rethink the whole thing).
I need a way to tell Bb or bB from BB so I don't have to make a lot of waste-of-time-and-space 'test crosses' crosses. Possible?
I want to use a BB guy (someone that will pass barring to ALL his offspring) for the next generation --- and would love to be able to pick one out without having to do lots of test-matings.
Thanks,

Lisa​

 

[Kev]

He is saying that normally, BB males are MUCH lighter than Bb males.

For examples, look at the difference in "color" between roo and hen pure Cuckoo Marans. The roosters are much "greyer" with much more white while the hens are darkish with smaller barring. That's the visual difference between BB and Bb(or B- in case of the hens).

B- denotes a hen with barring.. b+- a non=barred hen. Hens cannot ever be BB Bb or bb as it's on the sex chromosome. - is like "absent".. so a hen is either B- or b-.. Henk added / which is something some do for genetics.. To translate your BB into using this way, it would be written like B/B, B/b

In genetics notation + is the wild type gene. b+ is non-barred, lowercase because barring is dominant over wild type and that is why barring is written with uppercase B.

Your rooster looks like Bb (or B/b+, same thing, whichever helps you memorize/understand this better) to me also because his barring is "sparse" and he is not showing much barring on the tail. Normally BB males will have either rather strong or VERY clear barring on their tails.

For your project, mark the chicks with a much bigger head spot and especially if they show either a dusting of white or two parallel stripes of white on their backs(looking like mini skunks), those are almost guaranteedly BB males. Small headspots can be either the females or Bb males.

Lastly, if he was the only rooster and the eggs were not mismarked, the non-barred chicks are proof he is Bb (B/b+).

 

[Dipsy Doodle Doo]

Thanks Kev! I was thinking I'd find a minute to get chick pics before I responded, but haven't found that minute yet. That helps! I can see a definite difference in the head-spots.
I really need to get pics of the new generation from the barred wheaten Serama. None of the hens *show* barring. I think we talked about wheaten and barring before, but I can't remember. I'm at a loss to guess which hens are what. Thanks for being helpful... and patient with me.

Lisa