The mother of the commercial red sex links.

[NatJ]

I am 100% sure that the maternal stock is white rocks, carefully selected for more than 200 years for the purpose of hyper laying.

If you're sure, why did you make a poll?

And if they've been selected for 200 years, and this is 2021, they would have to exist from before 1821.

http://afs.okstate.edu/breeds/poultry/chickens/plymouthrock
"The Plymouth Rock was developed in America in the middle of the 19th century and was first exhibited as a breed in 1869."
also, "The first Plymouth Rock was barred."

So White Rocks (aka White Plymouth Rocks) have existed for less than 200 years. Some of the breeds used to develop them would have been already selected as good egg layers, but they were not yet White Rocks or any other color of Rock.

 

[Mitsos Lamprogiorgos]

True, and the sexlinks that come from that cross do have black tails. But the chicks are still sex-linked (can be sexed by color), and are predominantly red. So I included them, even though they are not the most common coloring.

Delawares are used by the industry in meat crosses. They are used in creating meat birds with a slower growth than the CX.

Check for sasso meat brids for hubbared meat birds and you will understand what I am saying.

Meat bird crosses are much more complicated than the layer crosses.

Layers are an f1 cross.

 

[MysteryChicken]

Has anyone looked at the article I linked?

 

[MysteryChicken]

Copied, & pasted from the article I linked.

"two purebreds were originally crossed to make this breed which was the Rhode Island Red male and White Leghorn female. Today, in order to produce a Red Sex Link The Rhode Island Red male can either be crossed by the White Plymouth Rock female, Rhode Island White Female or the Delaware female. Crossing them with these different breeds will probably cause the offspring to result in different temperaments though. This chicken is not recognized by the "American Poultry Association".

 

[NatJ]

Delawares are used by the industry in meat crosses. They are used in creating meat birds with a slower growth than the CX.

The Cornish Cross meat birds and the various Sexlink layers were ORIGINALLY created by crossing purebreds of various breeds.

By now, none of the parent stock for any of the commercial hybrids would do well in a poultry show. Some of them might not even be recognizable as the "breed" they orginally started out.

So we could claim that there are NO recognized breeds involved in the crosses by now.

As for whether Delawares are used for breeding meat birds or egg layers: either one, depending on how the line has been selected. They won't look like each other, but probably do trace their ancestry back to the same parent breed. (Same for White Rocks being used to produce Sexlink layers vs. Cornish Cross meat birds: very different now, same original breed, many generations of selection in different directions.)

Common hatchery-quality Delawares or White Rocks would not be a great choice for either purpose, because they have not been selected to either extreme (although they are probably closer to egg type than meat type, because the hatcheries would want as many eggs as possible from their breeder flocks.)

 

[Mitsos Lamprogiorgos]

The Cornish Cross meat birds and the various Sexlink layers were ORIGINALLY created by crossing purebreds of various breeds.

By now, none of the parent stock for any of the commercial hybrids would do well in a poultry show. Some of them might not even be recognizable as the "breed" they orginally started out.

So we could claim that there are NO recognized breeds involved in the crosses by now.

As for whether Delawares are used for breeding meat birds or egg layers: either one, depending on how the line has been selected. They won't look like each other, but probably do trace their ancestry back to the same parent breed. (Same for White Rocks being used to produce Sexlink layers vs. Cornish Cross meat birds: very different now, same original breed, many generations of selection in different directions.)

Common hatchery-quality Delawares or White Rocks would not be a great choice for either purpose, because they have not been selected to either extreme (although they are probably closer to egg type than meat type, because the hatcheries would want as many eggs as possible from their breeder flocks.)

Exactly!!!

But, bear in mind that a "common" white rock from a hatchery that is not selected for maximum production can thrieve in low density ecological feeding much better than a high octane white rock selected for the purpose of meat or for the purpose of eggs.