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PostPosted: Tue Jul 07, 2009 8:07 pm 
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Wise One
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A very good friend was able to source this Cockerel breeding Brown Leghorn Bantam Cockerel for me; it is colour I am interested in at this stage, not so much type. I am not very familiar with the differences between the cockerel & pullet breeding strains so thought someone may be able to help with some questions.

Firstly, what are the usual differences between the CB & PB strains colour-wise? I didn’t get the time to have a good look when picking this bird up (if honest I didn‘t think of it), but what I did notice was that the CB males/females were considerably darker than the PB males/females. I did notice the breast on a PB female as being the light salmon with brown/partridge body elsewhere so probably e+ allele, but not 100% sure of the colour of the CB females breast? I think it was a much darker hue ie red, but not brown/partridge (stippled), & a darker brown/partridge body with maybe some foxyness evident. If the CB female was partridge breasted but I don‘t think so from memory, then maybe the CB line is eb based??

The CB males were considerably darker than the PB males, generally, much darker pheomelanic areas, with clear broad black stripes in neck/saddle hackle. Don’t think the PB males had much if any hackle striping?

To me the Ap on those areas where it can be seen on this cockerel ie shoulders & back (not breast, although if you look closely you can see some red “edging” on some feathers I think) is very obvious. And I guess Ap would also account for the very dark breast & foxyness throughout body of the females.

So what else would be likely in the colour genome of this bird?? If not eb then e+, S-allele = s+, Ap is there I think unless I have this wrong. What about Mh?, would it be there to contribute to the intenseness in the Ap? But then it removes the black from breast of the male doesn’t it?. My reading suggests that it does darken the red on the shoulders & wingbow on males, & the salmon breast of the female?

Would the following be close do you think?

e+/e+, s+/s+ (s+/- female), Ap/Ap, Mh/Mh,?

Anything else? So we would have a (? dark) red duckwing is that correct?

What gene/s are responsible for hackle striping in this birds instance do you think???

Plan to mate this brown to a couple of white females in the next couple of weeks (when they come into lay). Will get some pictures of the chickens produced if all goes well & post them. Will also toe punch for colour. Really curious in the F1 generation @ this stage as to whether chicks seperate as per sex linked colours (if whites are S based).

Regards

Ross

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Last edited by rollyard on Wed Jul 08, 2009 12:54 am, edited 1 time in total.

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PostPosted: Tue Jul 07, 2009 9:50 pm 
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Wise One
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I had a conversation about this to Htul in a CB/PB thread a week or so back, i have never seen a CB hen that resembles eb, but apparently American Brown Leghorns (Light and Dark, PB and CB) are on different e bases. PB being e+, and CB being eb. Photos of the hens would really help. viewtopic.php?f=10&t=7976898

The CB look like they have Ar+ (or Ap, Autosomal pheomelanin or red) with Mh. Especially when you look at the hens wings, see this thread of BG's, notice the red shoulders? She started with a CB bird, so maybe they do have Mahogany :hmmm:
viewtopic.php?f=10&t=7977455

Nick

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PostPosted: Tue Jul 07, 2009 11:04 pm 
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Wise One
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Thanks Nick. Maybe it was the American birds that I have read something about in the past where CB lines are eb based. So probably not eb for the CB females that I saw then. The more I think about it the more I am sure that they were very red breasted so probably e+ based; should have taken more notice :x .

The way I read that link you provided Nick, the blue red pullet was bred form a CB Brown Leghorn male x white leghorn female? So the mother (white leghorn) must have been carrying the Bl gene then?

:hmmm: Bl must be hypostatic to I (dominant white), otherwise would it not express phenotypically over white when heterozygous if present??

I am tired & need some sleep :?

Thanks again :)


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PostPosted: Tue Jul 07, 2009 11:43 pm 
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Wise One
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Ok, like I said I am tired and on re-reading, just saw your first link Nick. Saw the post by Htul in that thread re: Cb & PB bown Leghorns. I did start reading that thread when first started but never got back to it. A shame because it would have enlightened me greatly.

Thanks again :)

Ross


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PostPosted: Tue Jul 07, 2009 11:49 pm 
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Gallant Game
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rollyard,

My understanding is that CB breeders should be eb based, but in recent discussions with others (following my discussion with Nick) I have been advised that many CB are probably not eb based in Australia (and apparently the situation is worse in the UK where CB lines based on eb have died out altogether). However, in the US, the "dark brown leghorns" have retained their eb base.

Along the same lines, my comments to Nick were that the CB pullets that he linked to appeared (to me) to have a salmon(ish) breast. Hence, my speculation that they might not be eb based (although on looking over them again - perhaps they might be e+/eb?)

Re: your interest in this cockerel over a white hen - it is probably unlikely that the resultant offspring will be sex-linked even though, in all likelihood the white hen will be S based. This will be due to the fact that most white leghorns are ultimately E based which is epistatic to the S/s+ down colour, as is the dominant white that is likely to be producing the white.

Blue (which is really a modified form of eumelanin) is hypostatic to dominant white.

I can't really shed much light on the dark striping - blackdotte may have some thoughts on this.

...and I will refrain from much comment in the way of autosomal red gene(s) (those of you who have seen some of my prev comments will see what I am driving at)- but if the current trend is to accept "Ar+" (ie. as a single gene) then that is more correct than Ap - which has been assigned to apterylosis. But yes, there probably is some sort of involvement of autosomal red (be it single gene or polygenic).

On a minor technicality re: terminology: "genome" to me, is not really correct. "Genotype" - yes, but "genome" refers to the entire genetic content of the organism, rather than just a few isolated gene loci.

Cheers,
Htul


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PostPosted: Wed Jul 08, 2009 12:29 am 
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Wise One
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Thanks Htul :)

Like I saidI am tired and will have to read this tomorrow again to absorb it fully (with book in hand :lol: ).

But just breifly, I thought personally that it would make more sense colourwise for the CB birds to be based on eb, probably due to the idea behind a CB being to produce just that, well coloured (plus type I suppose) Cockerels. The darker base to me would contribute greatly to black breast etc.

As for the colour sex linkage, I take it you are saying that the silver down colour will be hidden by the E mutation chic down colouring, and/or the I dominant white colouring. And heterozygous blue is hidden if I dominant white is present also.

I am very new to colour genetics Htul, and would be very interested in a link to your thoughts on Ar+ as opposed to Ap. I was not aware that Ap was viewed as more than one gene. Some sources of my reading use the notation Ar, while others Ap, which I have always assumed was a single gene?? :? I continue to learn, even when tired :)

I must have confused re: the proper meaning of "genome" I was under the understanding that the term "genotype" was used when describing the complete genetic constitutuion of the organism. Thank you for clarifying :)

Am very greatful for your help.

Oh, and what does that mean, apterylosis :shock:

Regards :)


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PostPosted: Wed Jul 08, 2009 11:29 am 
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Prime Pekin
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Whilst CB should be eb based with gold, mahogany and 'recessive blacks' to get the same dark red as found in RIR (eWh based) and Red Sussex (eb based) it is also possible on a Duckwing e+ base, as in the dark red Spangled OEG.
David


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PostPosted: Wed Jul 08, 2009 3:21 pm 
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Wise One
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Thank you Blackdotte

Regards :)


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PostPosted: Thu Jul 09, 2009 6:21 pm 
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Gallant Game
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No problem rollyard.

Funny thing about eb really - theoretically, eb, e+ and ewh cockerels should be phenotypically the same as BBR, and the difference in phenotype is based on females, but I think there are quite possibly subtle differences between them. I have discovered that a good example of "plain eb" is apparently CB breeder partridge wyandottes (eg. as they exist in the UK - I don't know the situation here).

Re: sex linkage - the silver down is being masked by dominant white and E (although, each on its own will be similarly able to mask the S). Hence, you shouldn't be able to distinguish gold/silver sex linkage where either I or E are involved.


Feel free to browse my thoughts on autosomal red - I don't dispute this exists, but am cautious in concluding that it is definitely attributable to a single gene, at least based on the evidence that I have seen that is meant to demonstrate single gene involvement:

viewtopic.php?f=10&t=7973831&hilit=autosomal+red

and also: http://www.the-coop.org/cgi-bin/UBB/ult ... 3;t=002437 (you will also be able to find many long-running discussions re: Autosomal red at The Coop)

If referring to autosomal red, Ar is the correct terminology, not ap, as the 'ap' symbol is assigned to another gene (apterylosis - which is autosomal nakedness), but as you have pointed out, some people erroneously have used ap in the past.

Cheers,
Htul


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PostPosted: Thu Jul 09, 2009 7:43 pm 
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Wise One
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Thank you very much for info Htul, I do appreciate it greatly.

I think I understand what you have said about eb, e+, & eWh males expressing as BBR (although maybe differing shades in red??), and counterpart females are the signals which more clearly demonstrate the differences in colour bases (as adults). Any more subtle differences between the eb, e+, & eWh males other than the shades of red, are beyond my level of knowledge I'm afraid.

Thanks again for extra info re: sex linkage. Understand now that I won't be able to sex chicks on down colour, as both E &/or I (& the white Leghorn hens are almost certain to have one or both) will mask S, but will continue with my little project. I think it will be a great reinforcing tool, and if/when other colour is exposed in the F1/F2 generations, may help assist my understanding of colour genetics, and am happy to acknowledge at this stage, I need all the help I can get :lol:

Thank you for the links; am sure I will learn from them and look forward to some interesting reading. Actually, I find it most interesting when differing viewpoints and ideas are put forward, sometimes helps me to see more clearly, if that makes sense.

Yes, I have read from different sources, some of which use the different terms Autosomal pheomelanin or Autosomal red ie Ap & Ar. The source that uses the Autosomal pheomelanin Ap term is quite forceful I feel when demonstrating that this is the correct terminology. I will ensure in the future to use Autosomal red Ar as you suggest though. At my very early level of learning Htul, I guess I am very impressionable, and therefore, go with whoever puts forward a good argument; not necessarily a good approach I concede, but suppose I have to start somewhere.

You have helped a great deal Htul, thank you again :)

Regards :D


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PostPosted: Thu Jul 09, 2009 11:02 pm 
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Gallant Game
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You're welcome rollyard - glad I could help.


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