F1-F2-C1 question

[tadkerson]

most wheaten chick

correct, and thats why I say keep all of the wildtype looking chicks..

why?

say you want to start a breeding program to enhance the Rhodebar Type(as in color, Body and Type) using Heritage Rhode Island Reds..


the First Cross would be Rhodebar Male x HRIR Female, this would produce about 50% wildtype looking chicks(that is consistance with Recessive Wheaten) and 50% Wheaten looking chicks(even if they look different from foundation stock, these difference could be because lack of Mahogany or other genes)...

This Wildtype Looking chicks are the Keepers, Why? because they are e+/ey(recessive wheaten) or e+/eb in any case you KNOW they carry one copy of wildtype, which is what you want for an Autosexing breed... now this F1s as good as they may be they would only be 50% HRIR, meaning they will not be homozygous for many of the good genes found on HRIR.. so what to do to improve them? BackCross to HRIR, would do the trick..

50% of these BC1 would be also Pseudo wildtype looking, these chicks are the keepers, why? because you know they carry e+, this e+ chicks would be your ticket to better Rhodebars, keep the BC1 e+/ey(Pseudo Wildtype) Barred Female...

the BC1 Barred Female genome would be e+/ey s+/- Mh/Mh Co/Co B/- and when cross to Pure Rhodebar male, would produce 100% Barred Chicks and probably 100% Autosexing Chicks, and I say probably because I just dont know how would a e+/ey B/B male would look like, but if its infact ey(recessive wheaten) chances are that the males would be also autosexable...



What do you think of that breeding Plan Tim? keeping in mid that these Pseudo wildtype chicks would be your e+ gold pot...

Back crossing to the rhodebar does two things
1. maintains the wild type allele in homozygous state in the breeder offspring
2. allows for the proper barring in the offspring ( males two and females one)

These two things are needed for auto-sexing.

A BC1 rhode bar male can then be back crossed to the HRIR and the same regimen followed again. Do this until the Rhode bar are where the breeder wants them.

This would be very easy to follow. The regimen you are suggesting may produce a Rhode bar more like a HRIR faster but the way I am suggesting is less complicated and much easier to do.

If the peudo-wild type down is due to the brown alelle, I am not sure if it will behave like the wild type and produce a down color that is auto-sexing.. It has to do with how the brown allele functions on the cell level. The brown allele expresses a product that is constitutive just like the brichen allele and the extended black allele. Please do not ask me to explain the difference it is complicated and would take a lot to explain.

Tim

 

[tadkerson]

Thanks Marvin and Tim. Now let me ask you both this, why is it in the UBC poultry auto-sexing programs did they not strive for the head spot and instead, from the reading I have done, seemed to be focused on the actual dark spots/lines on head and body as well as coloring to use in sexing? I just have not been able to wrap my head around that aspect of their programs.

Penny

Head spot ( male) is a sex linked trait used to identify male verses female black sex linked chicks

light down (male) verses dark down (female) is used to identify most auto-sexing breeds.

Tim

 

[RedRidge]

So let me make sure I understand the differences in the two recommendations...
Marvin recommends breeding wild type looking F1 Females back to a HRIR to achieve BC1s.
Tim recommends breeding the wheaten looking F1 males back to a RB female. Why? Because when that does produce a few wild type chicks you will know for sure what you have.

Am I understanding this correctly?
If so... I may set up pens of each since I have enough birds to do that.
Course at this point my curiosity is leaked just enough that I'm thinking about setting up the breeding pens... Two as described above and a third with wild type looking F1s back to a RB. Lots of anal tracking but a fun fall project.
If I'm not understanding correctly please bear with me and be more specific.

 

[RedRidge]

 
Thanks Marvin and Tim. Now let me ask you both this, why is it in the UBC poultry auto-sexing programs did they not strive for the head spot and instead, from the reading I have done, seemed to be focused on the actual dark spots/lines on head and body as well as coloring to use in sexing? I just have not been able to wrap my head around that aspect of their programs.

Penny

Head spot ( male) is a sex linked trait used to identify male verses female black sex linked chicks

light down  (male) verses dark down (female)  is used to identify most auto-sexing breeds.

Tim

Tim, are you aware that the pure RB here in the US are autosexed via white or cream head spots on the males? And yes they breed true. Here are some I hatched at one point... Not all keepers but both sexes are in this pic. These are Pure RB, not F1 - just to make site there is no confusion.

 

[melroseladi]

LOL, I am so confused. I think I may do RB x F1 cross, a HRIR x F1 cross, a F1 x HRIR, and a F1 x F1 (then backcross the F2's) if I end up with enough females. I would think that one of these crosses should start producing better RB and males with head spots.

Penny

 

[RedRidge]

LOL, I am so confused. I think I may do RB x F1 cross, a HRIR x F1 cross, a F1 x HRIR, and a F1 x F1 (then backcross the F2's) if I end up with enough females. I would think that one of these crosses should start producing better RB and males with head spots.

Penny

Ah see! So you are thinking about different paths too.
My husband says that it's obvious that you and I are female and Tim and Marvin are male. The guys don't care if they read the map... close is good enough and will get you there eventually. If they get somewhere they don't want they just go the other way. But you and I? We want a map of the entire trip AND to stop for directions periodically. ROFL

 

[melroseladi]

Ah see! So you are thinking about different paths too.
My husband says that it's obvious that you and I are female and Tim and Marvin are male. The guys don't care if they read the map... close is good enough and will get you there eventually. If they get somewhere they don't want they just go the other way. But you and I? We want a map of the entire trip AND to stop for directions periodically. ROFL

Amen to that, LOL. I probably will change my breeding plans 10 more times before these chicks are even old enough to lay an egg. I do think my darkest striped chicks from first hatch are all female. I thought that 1 was male but it is looking/acting more female now. The medium and light chicks are feathering out with different coloring then the dark ones. Lighter ones are showing visible lighter coloring barring on wings and back. The dark ones do not have that lighter coloring on the wings and back.

Penny

 

[RedRidge]

Ah see! So you are thinking about different paths too.

My husband says that it's obvious that you and I are female and Tim and Marvin are male. The guys don't care if they read the map... close is good enough and will get you there eventually. If they get somewhere they don't want they just go the other way. But you and I? We want a map of the entire trip AND to stop for directions periodically. ROFL

Amen to that, LOL.  I probably will change my breeding plans 10 more times before these chicks are even old enough to lay an egg. I do think my darkest striped chicks from first hatch are all female. I thought that 1 was male but it is looking/acting more female now. The medium and light chicks are feathering out with different coloring then the dark ones. Lighter ones are showing visible lighter coloring barring on wings and back. The dark ones do not have that lighter coloring on the wings and back.

Penny

Since the entire group has to be single barred it will be interesting to see how they evolve.

 

[melroseladi]

Since the entire group has to be single barred it will be interesting to see how they evolve.

Right, they should all be single barred but I think it is expressing more on the lighter chicks then the darker chicks. Now if all the darkest striped hatchlings turn out to be female then that would at least be a start. I think we may have a bit more difficult time since our Reds are so dark versus hatchery Reds that are much lighter. I guess time will tell.

Penny

 

[RedRidge]

... I think we may have a bit more difficult time since our Reds are so dark versus hatchery Reds that are much lighter. I guess time will tell.

Penny
[/quote]
I think you have hit the nail on the head. Some of my F1 cannot easily be distinguished from my HRIR so I have decided to make sure the two groups are not only marked as I had originally planned, but I have decided to use separate brooders and grow out pens.
In the long run it will be to our advantage using the higher quality HRIR, but for the next few generations is going to make our job a little tougher.