F1-F2-C1 question

[tadkerson]

No please. .. Go ahead and complicate it.
Show us the differences between these heterozygous wildtype and some homozygous wild type. I'm very visual. .. I'd like to see the differences.

My point is that if you back cross the F1 wheaten down chicks with the RB- in the back cross offspring the purebred BC1 wild type chicks ( these are what you want) will be easily distinguished from the BC1 wheaten chicks ( you do not want these).

You can not always tell the difference between wild type and pseudo-wild type down. I focus on the head of the chick and look for a point on the brown on the head. The brown patch should also be wide and have straight edges. The eye stripe should also be long and wide.

The back should be uniform with stripes that run parallel and straight. Nice wide central brown stripe that narrows at the neck and runs on top of the head. Cream and brown stripes are parallel and with even edges.

Like I said heterozygous (hybrid) birds can have the same characteristics as purebred wild type down.

Tim

 

[RedRidge]

Note this is really confusing to me since the chicks with the brown point in the head never looked like what we started with. Why would we expect a marking that the foundation stock never exhibited?

 

[melroseladi]

Okay so our RB are only pseudo wild type and our F1's are pseudo wild type so if we do a BC then some of the offspring will be true wild type and those would be the ones we keep?

Penny

 

[nicalandia]

I would back cross a F1 female(s) that had wheaten down as a chick to a RB. This way the BC1 that are wild type ( the keepers) will have a distinct down color (wild type) over the wheaten/wild type heterozygous ( wheaten down) chicks. All the wild type down chicks should be homozygous (purebred) for wild type.


Tim

Tim I would advise the other way around, use the Wildtype looking e+/ey or e+/eWh(I truly believe its the same wheaten gene affected by other factors) and cross it back to Rhodebar..

 

[nicalandia]

Okay so our RB are only pseudo wild type and our F1's are pseudo wild type so if we do a BC then some of the offspring will be true wild type and those would be the ones we keep?

Penny

No, your Rhodebars should be pure for Wildtype, and the Pseudo wildtype could be recessive wheaten infact, Or could be dominant wheaten but affected by other genes...

 

[nicalandia]

Why would we expect a marking that the foundation stock never exhibited?

most wheaten chick

My point is that if you back cross the F1 wheaten down chicks with the RB- in the back cross offspring the purebred BC1 wild type chicks ( these are what you want) will be easily distinguished from the BC1 wheaten chicks ( you do not want these).

You can not always tell the difference between wild type and pseudo-wild type down.
Like I said heterozygous (hybrid) birds can have the same characteristics as purebred wild type down.

Tim

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...

 

[melroseladi]

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

 

[RedRidge]

Excellent question Penny... I'd like to know that too. I'm documenting "I's" and "T's" on heads as they are dark.
I decided today to go ahead and document each chick separate instead of in groups since conflicting information about markings is cropping up. I want to be able to go back later and track rack and every chick.

 

[melroseladi]

Excellent question Penny... I'd like to know that too. I'm documenting "I's" and "T's" on heads as they are dark.
I decided today to go ahead and document each chick separate instead of in groups since conflicting information about markings is cropping up. I want to be able to go back later and track rack and every chick.

What I am thinking is in the UBC studies they did not add genes for wild type so they were working with wheaten. I am sure Marvin and Tim can clarify if that is the case or not. I am just going to work with my F1's that are hatching with the good dark wild type striping, oh and the little mahogany and burgundy colored chicks.

Penny

 

[tadkerson]

Note this is really confusing to me since the chicks with the brown point in the head never looked like what we started with. Why would we expect a marking that the foundation stock never exhibited?

If your rhode bar did not fit the description then they are not wild type. It may be that they are what I call a default or pseudo-wild type. Is there any difference in your F1 offspring down color and the down color of the rhode bar? Excluding the wheaten down F1 chicks- I am not asking if your rhode bar looked like the wheaten down F1 chicks.

Tim