McMurray's cornish x - are they really?

[halo]

I was reading another thread about meat chickens where someone stated that the cornish cross are always a cross between 2 breeds. You know, I was wondering, on McMurrays website, they state their cornish x are a hybrid, and therefore you shouldnt breed them as you won't get a cornish x. But then I wonder, are they actually a pure strain of some type of Cobb bird, since that is exactly what they look like, and they just keep calling them a cornish x so they don't have to call them what they actually are, or because they can't call them what they actually are for privacy purposes. Or are they actually a pure strain that they have developed over the years, that they still call cornish x for continuity sake.

I really have a hard time believing that if you took a boy and girl of their cornish x, that the resultant chicks wouldnt be exactly what the parents are.

Im just wonderin....

 

[terri9630]

They are a cross between a cornish and another breed and won't breed true because they are half breeds. They are bred to grow fast and don't usuall live long enough to breed.

 

[halo]

Well, thats the point Im trying to make, because I dont think they are that cross, not anymore. Im thinking they get their same meat chicks from every other hatchery and that the meat chicks are now far more than just a cross between a cornish and a rock. They keep saying they wont breed true, but Im not sure Im believing it. Im sure way back in the beginning of time, it was a cross of a cornish and a rock, but now, millions of generations later, its a far more sophisticated chicken than just a cornish cross. If you look up Cobb chickens, theres a lot of information about the modern day broiler, and Im thinking thats what they are selling; if not exactly the same, then the same general bird.

Seems like theres been a discussion on this, I need to search.

 

[AZKat]

It is more sophisticated than a cross between a Cornish and a Rock, in the sense that that the parents and grandparents of the final Corinsh X are very carefully bred as well.

 

[Brunty_Farms]

If you could get them to breed, which you can with good management. The resulting chicks will resemble their parents, it's simple genetics. However you lose a bit of hybrid vigor when doing so and they don't preform quite as well but close enough...

There are actually three crosses that go into producing that final product. You have Great Grandparent lines, Grandparent lines, and Parent lines. The Great Grandparent lines resemble very close to the standard cornish and rock. The more you cross new genes in, the better the genetics will be for the next generation. However the Parent lines resemble the end result almost identically, if they are both raised on full feed the average person wouldn't be able to tell the difference.

Again the crosses just resemble the hybrid vigor. The only inbreeding that is really in these lines, or a better word for it would be line breeding, are the Great Grandparent lines. These are the only lines that are truly pure and breed true over and over again. Back to the hybrid vigor though, the more crosses you use, the healthier the bird will be and the better it will preform. You get better egg production, meat production, and overall better health than a typical DP breed.

If you notice, even the standard layers in the industry are now being crossed to produce a better bird. When your talking about money and profit, it doesn't come down to keeping pure lines of breeds but rather finding a way to produce the best for your money. Even the leghorns you see today in commercial settings are not pure, they are a cross between two lines.

Now, with DP or any other breed for that matter, there is a lot of inbreeding or "line breeding" as many call it. The gene pool is limited and in result you have so many lines that are so far from the standard that they are not usable in commercial production. Such as the White Rock or even the standard Cornish. Either bird is readily available, the White rock is a true DP breed but there are very few lines in the country, or world for that matter that mimic what they looked like 50 years ago. It's basically lack of genetic diversity, but some very good breeders in this country have found ways to better the gene pool. Some will take another breed very similar to the one they are working with and bring new genetics in by crossing the two. Using the offspring to breed back to the father or mother to tighten up the genetics a bit. But that one single cross will produce hybrid vigor, resulting in better genes, better laying, and better growth. Which is why the industry has taken full advantage of crossing every chance they get.

But the difference in different breeds of cornish crosses is very small, the normal person would not be able to tell really the difference. However in fairness to McMurray, they may have 2 or 3 lines of broilers. There are lines out there that are roaster lines and bred to be processed at 9-10 weeks (males) If McMurray really has that.... who really knows?

 

[raventearsx]

My sister in law gets these birds every year for meat. They are cornish crossed with rocks, but I'm pretty sure the breeding is selected at least 2 generations back to get the birds that grow so fast. Sis-in-law can barely keep them until butchering date because they get so big so fast, and eat so much!

 

[halo]

Jeff, thanks for that reply. So are you saying they are crossing different lines of Cornish, or different lines of Cornish X? With the size and growth of these meat birds now, it doesnt make much sense that just crossing a cornish with a rock would produce a bird that finished out in 8 weeks, since neither of those birds do anything like that, hybrid or not.

So Im thinking that these different lines, or strains you are talking about, are their own strains developed over time.

Ravenstear, did she get chicks from McMurray?

 

[SteveH]

Quote:
The parent lines themselves are already crosses . They probably all share white Cornish and Plymouth Rocks as their very original ancestors , but they're far removed from those two breeds today . Some will have one male line that is used over two or three female lines , or possibly have more than one male line ........ these genetics are pretty closely guarded . The reason there are more than one line is for specialty commercial growers ; one may provide meaties specificly for the demand of boneless chicken , another for whole roasters or cut up friers , and some will raise a bird that is suitable for either but not quite as efficient as either of the two other specialty lines . Research is always being done on parent lines to see if they can gain another slight advantage ; just the slightest gain in feed conversion , carcass quality , or livability makes a huge impact to the targeted customer , which are commercial growers raising thousands of meaties per year . It takes two lines that niche together perfectly to get that hybrid with a slight advantage , so breeding that final product does not give you that niche . The two parent lines are only used untill they're around 60 weeks ; by that time production of viable hatching eggs in comparison to what it costs to feed them ....... plus the fact that even on their restricted diets they are growing too large to successfully mate ........ causes them to be replaced . I read that half way through their short time of productivity they sometimes " spike " the breeders by replacing the large male birds with a new set off the same line that were kept back on special restricted diets to keep fertility at its maximum .

 

[halo]

Great information, thank you. That basically confirms what I thought, that they are not Cornish X anymore, per se, they are generations removed from that Cornish x White Rock that people still seem to think they are.

They are their own breed now, I dont know why they still call them Cornish X.

 

[Milliemay]

Whatever they are, they are delicious! Down to about 9 left out of 30 in the freezer. 20 ordered to be here soon so we can start all over. I LOVE SPRING!