Breed this possible

[Andy809]

Hello, I was checking out the isa browns hydridization, and I'm unable to really understand how it is possible to make isa browns. If someone can understand it, could you please see the attached photo and assist me?

 

[NatJ]

Yes, but how is it that nobody could figure out the crosses?

It doesn't even have to be a secret, if they just refuse to sell any of the pure lines (A, B, C, D).

Making color-sexable chicks is pretty easy. Making ones that lay as well as ISA Browns is not nearly as easy. That takes a lot of careful breeding work.

If you want color-sexable chicks, you can use Delaware hens with Rhode Island Red roosters. The daughters will lay about as well as the parent breeds do (probably not as well as the ISA Browns). There are quite a lot of other breed combinations that will also produce color-sexable chicks.

 

[NatJ]

(A)RIR/New Hampshire, (B)White Leghorn/White Rock, (C), Silver Leghorn/White Leghorn.
Females would be White/Silver birds.

The other line must be red, to make the color-sexing come out right for the end product. It might just be another line of Rhode Island Red or New Hampshire.

Given how brown the eggs are from some ISA Browns, I would not expect to find any Leghorn in them (at least, not recently-introduced Leghorns, because that would cause them to lay lighter colored eggs.)

 

[Andy809]

It would make more sense to use Leghorn due to the higher production rate.

I've seen various shades of brown in some cartons at the store. Copper brown, to cream.

I don't really see many people crossing RIR w/ leghorn and it sounds like an isa brown mix to me.....people like to use RIW X RIR

 

[NatJ]

I thought it was barred Plymouth

I suppose I don't know for sure what color it was, but the current Cornish Cross are definitely white, and I've never heard of "Cornish Cross" in any other color.

Chickens with white feathers have white pinfeathers, which do not show as much if you miss a few when plucking the chicken. White turkeys are common for the same reason.

So I can't remember whether I actually read that the original cross used White Rock, or whether I read that it used Plymouth Rock and I assumed the White color rather than any other color of that breed.

RIR X White Leghorn was the original Red Sex-link cross. Now there's various other combinations creating different lines of sexlinks.

The White Leghorns that are commonly available now cannot produce sexlink chicks. They have Extended Black and Dominant White, so crossing them to any rooster will just give white chicks for both males and females.

So if the original Red Sexlinks were made with White Leghorns, those Leghorns must have had a different set of color genes than the ones that are so widely available now. They must allow large amounts of silver or gold to show, to be sexable by color at hatch.

 

[Andy809]

Pretty close, yes.

What they probably really did:

Breed white hens and red roosters, raise a bunch of daughters, keeping track of which daughters came from which parents. See how well the daughters lay.

Take the white hens and the red roosters that produced the very best daughters, and breed each of them to mates of their own color, to get more white chickens and more red chickens.

Using that new generation of white chickens and red chickens, breed the white hens with the red roosters and keep track of the daughters so you can find which parents were the best...

Repeated over and over, for many years.

They eventually ended up with the current set of chickens, that are probably not recognizable as any specific pure breed, but that are very good for producing ISA Browns.



Looking at that chart in the first post, I would say that A and B would be two lines of white chickens. Breeding them together gives the white hens that become the actual mothers of ISA Browns. C and D would be two lines of red chickens. Breeding them together gives the red roosters that become the fathers of ISA Browns. Each year they are also breeding A roosters with A hens, and B roosters with B hens, to get the pure As and Bs they will be crossing next year (and C roosters with C hens, and D roosters with D hens.)

The only thing that keeps you from doing the same thing yourself: space to raise a lot of chickens, money to pay for the housing and feed for all the chickens, and how much time you are willing to put into the project.


Sort of yes, sort of no. Each of the lines of chickens (A, B, C, D) would be like a breed, in that it can reliably produce more chickens like itself. But it is not a breed that has a name, gets sold by hatcheries, raised by private breeders, entered in chicken shows-- so in that sense it is not really a "breed" as we usually use the term.

Understood thank you very much.

 

[Andy809]

I have an idea what the mixture is for A,B,C, but can't think of what D would be, unless it's a repeated mix of A, or B.

Whats mixtures do you have? For A B and C? Also whats breeds can you make isa browns? And what breeds to make CornishX?

 

[NatJ]

I have an idea what the mixture is for A,B,C, but can't think of what D would be, unless it's a repeated mix of A, or B.

What would you expect?

I would expect two lines (maybe A and B) are all white (Silver plus Dominant White).

I would expect the other two lines (C and D) to be red (like Rhode Island Reds or New Hampshires.)

They might have a fast-feathering and a slow-feathering line of each color, so when they cross them they get feather-sexable chicks. That would save them hiring vent sexers for the white and red parent stock that are crossed to produce the actual ISA Browns.

I would expect the A and B lines to be different enough that A x B produces chicks with some hybrid vigor, and the same for C & D.

 

[MysteryChicken]

Whats mixtures do you have? For A B and C? Also whats breeds can you make isa browns? And what breeds to make CornishX?

(A)RIR/New Hampshire, (B)White Leghorn/White Rock, (C), Silver Leghorn/White Leghorn.
Females would be White/Silver birds.

Cornish cross, I'm still working out. I know that White Cornish X White Plymouth Rock is one of the parent crosses. I do know there's a white skinned bird used in the mixture, but have yet to solve that mystery. (I had a Cornish X with white shanks, & beak amongst 9 with the normal yellow shanks.)

 

[NatJ]

And what breeds to make CornishX?

To make CornishX (also called Cornish Cross, or Rock Cornish Cross, or other variations of those names):

Originally, decades ago, White Plymouth Rock hens bred with White Cornish roosters.

The hybrid chicks grew fast and had big breasts (as compared with other chickens available at the time.)

Of course people tried various other combinations of breeds, and started selectively breeding for the traits they wanted in the chicks.

By now, there special lines of parent stock (that you can't buy anywhere). Two lines are crossed to get hens who lay lots of eggs (so they can hatch lots of chicks) and grow pretty well. Two other lines are crossed to get the right roosters to breed with those hens. Roosters don't have to lay eggs, so the rooster line would be selected especially strongly for fast growth and lots of meat.

The Cornish Cross chicks they produce will grow fast, to a large size, but they have health problems if you try to raise them past about 8 weeks of age. Their parents would have the same health problems, except that they are raised on very limited feed (semi-starved to stunt their growth, so they are closer to normal chicken size instead of enormous balls of meat.)


If you repeat the original cross of White Rock x purebred Cornish, you will find that they grow much slower and are much smaller than the modern Cornish Cross. So the name stuck, but none of the parent types would match any recognized breed of chicken.