Cornish Rock Meat Bird Breeding Project

[nicalandia]

Hybrid vigor is a real thing.

In Commercial lines Hybrid Vigor is all but dead(in both broilers and egg laying strains), what they use is complement breeding.

Parent Sire Line A is selected for the most growth regardless of egg production(5.5 pounds at 5 weeks of age), Parent Dame line C is selected for better egg production(which is about 160 eggs at 60 weeks of age) but they also have exceptional growth(5.2 pounds at 5 weeks of age) when both lines are crossed the best you can hope is the Average of the parents and that is what you get in the Terminal Cornishx cross

 

[trescloudy]

The male lines are fed ad libitum until they reach about 5.5 pounds, which they do at about 5 weeks of age

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After that(reaching about 5.5 pounds) they are starved and only gain about 3 pounds on the next 15 weeks(About 8.3 pounds at 20 weeks of age) and another 4 pounds at 60 weeks of age(about 12 pound males)



Now I don't think we should do the same drastic program(Feeding Ad Libitum like broilers and then starving them to death for breeding), the terminal males we get from the stores can be feed restricted as the females at hatch.


https://cobbstorage.blob.core.windows.net/guides/3450c490-bbd7-11e6-bd5d-55bb08833e29.pdf

Interesting stuff

 

[trescloudy]

In Commercial lines Hybrid Vigor is all but dead(in both broilers and egg laying strains), what they use is complement breeding.

Parent Sire Line A is selected for the most growth regardless of egg production(5.5 pounds at 5 weeks of age), Parent Dame line C is selected for better egg production(which is about 160 eggs at 60 weeks of age) but they also have exceptional growth(5.2 pounds at 5 weeks of age) when both lines are crossed the best you can hope is the Average of the parents and that is what you get in the Terminal Cornishx cross

They are making hybrids to cross to hybrids so I cant agree that hybrid vigor is dead in the meat bird game. You wont find any heritage birds that grow remotely close to CX because well, inbreeding doesn't produce extremely fast growing birds....

 

[Compost King]

I think people get too hung up on "hybrids don't breed true"

I have to agree with that, people get hung up on that as if someones goal is to get them to breed true. Breeding CX is going to result in some very large fast growing offspring that do not breed true... and when I am at the dinner table I am not going to care if they breed true. There are different lines of CX and if you get a male from one line and a female from another line you may even get a bit more vigor... not sure because I never did it but I bet it's worth the effort to try. Right now I have 3 cx off to the side for crossing with a heritage breed large foul or a mutt or what ever I have available as far as rooster go. Maybe I will spare the smallest male in my batch too just to see if I can pull off breeding CX to CX. I think @duluthralphie calls them a lizard lol.

 

[trescloudy]

I have to agree with that, people get hung up on that as if someones goal is to get them to breed true. Breeding CX is going to result in some very large fast growing offspring that do not breed true... and when I am at the dinner table I am not going to care if they breed true. There are different lines of CX and if you get a male from one line and a female from another line you may even get a bit more vigor... not sure because I never did it but I bet it's worth the effort to try. Right now I have 3 cx off to the side for crossing with a heritage breed large foul or a mutt or what ever I have available as far as rooster go. Maybe I will spare the smallest male in my batch too just to see if I can pull off breeding CX to CX. I think @duluthralphie calls them a lizard lol.

Inbreeding a hybrid line will produce inconsistencies in the first 2 or 3 generations or more if selected incorrectly.

I believe if we were to work through it and line up the right males to the right females we could unravel the mess to a degree. Of course knowing what to look for would be a big help and makes unraveling back to the 4 original lines quite unlikely.

But if we could get a nice wide breasted cornish looking bird with a nice stance that can move around without looking crippled we could breed with those until we stabilize that line.

From there we could outcross for vigor and possibly even have a stabilized meaty variety or 2.

I purchased 6 broiler hens with full intention of using them for breeding stock. They are at 7 weeks right now. Im going to pick the birds that have the best structure for laying hens. Also plan on keeping 2 or 3 broiler roosters.

Good luck and feel free to share your findings. I'll be posting a lot more once the breeding starts but really enjoy chatting about this stuff. Maybe we can do some bird trading next year too.

 

[nicalandia]

They are making hybrids to cross to hybrids so I cant agree that hybrid vigor is dead in the meat bird game.

I have provided enough evidence to support my claim that they are not exploiting any type of vigor to increase FCR when the grand parents have the same FCR as the terminal cross. How would anyone argue about heterosis when there is none to speak of?

The GP line of Broilers can get so Fat that they need to be Starved for their productive Life in order to obtain 160 chicks per hen. at 20 weeks of age these hens are 5 pounds and at 60 weeks of age(end of productive life) they are 9 pounds with about 100 grams of feed per hen a day.

 

[duluthralphie]

I have provided enough evidence to support my claim that they are not exploiting any type of vigor to increase FCR when the grand parents have the same FCR as the terminal cross. How would anyone argue about heterosis when there is none to speak of?

The GP line of Broilers can get so Fat that they need to be Starved for their productive Life in order to obtain 160 chicks per hen. at 20 weeks of age these hens are 5 pounds and at 60 weeks of age(end of productive life) they are 9 pounds with about 100 grams of feed per hen a day.

I have no idea what your studies are or your background is.
You can be most certainly correct on the parentage of the birds.

When I was doing the work with toads (and lizards) I simply took the birds I liked best or thought had the best Chance of breeding.

Toads and lizards can get so fat they cannot walk or reproduce also. It takes them very little to survive. They are extremely efficient at turning junk calories into meat.

20 weeks of age and 5 pounds is pretty small. I was doing 12 pounds at 9 weeks on my eaters.

I have two toads left an old hen and a 2 year old hen. They both have Dominques blood in them.

One is a barred toad with a huge breast and legs, far larger meat to size ratio than my dual purpose birds, and she still lays about 4 eggs a week. She is a sweet heart, wants to jump into my lap a lot. The other day she tried to get to my shoulders from the ground.

The other is a white (nearly naked) looking toad, slightly taller than the other toad, larger breasts and legs. Not as friendly as the other toad but still social.


I keep them in a separate pen from my other birds, they have a Dominques boyfriend. We think he has a fetish’s for the chubby girls. He follows them everywhere. He was living in the large coop and just decided to move in with the girls.

Now for the part that will turn you all against me.

I starve these birds by all normal standards.

I give them a small scoop of feed once or twice a week. They have to survive on what they find. Bugs, weed seeds, and so forth. If I did not starve them they would be as fat as me and die of a heart attack.

I sometimes slip them feed only because of their boyfriend, he cannot live on the scraps the toads live on.

There is nothing spectacular about these toads, until you look closely at the breast and thighs they are about 2 inches wider than a normal bird.

I will try to remember to snap a couple photos. If I do remember it is summer here and the toads lose feathers to help stay cool.

 

[duluthralphie]

Toad eggs on the edges EE in the center. 2.8 ounces.


I have had them at 4 ounces but this last generation is more in line with larger jumbo egg.

 

[nicalandia]

I have no idea what your studies are or your background is.
You can be most certainly correct on the parentage of the birds.


20 weeks of age and 5 pounds is pretty small. I was doing 12 pounds at 9 weeks on my eaters.

I am sure you don't starve your breeding flock as much as it's recomended for full production breeding,

 

[speedy2020]

Ok I've read a lot of posts at BYC about breeding with the Cornish Rock or Cornish cross aka CX.

I've actually accomplished crossing other varieties to CX hens, that's easy. I want to try a few different ideas I've been tossing around and maybe some others I've recently come across though.

One of my older ideas was inbreeding the CX which a lot of people think is impossible but probably not so many here at BYC because of @duluthralphie and his work with the CX crosses.

I admire his determination and knowledge a great deal. He actually mated CX roosters to CX hens and hatched offspring without using artificial insemination. I have to admit I actually tried artificial insemination on CX and failed but think I could accomplish it now after watching some YouTube videos on the exact topic.

I like Ralphies dedication to making it happen natural but I think a little differently on this topic. Im definitely not against letting nature do its thing because it is so much easier. Probably even more so once the initial "f2" is made. Theoretically inbreeding CXs should slowly take the hybrid vigor out of the line. From there I think if it was done with proper care you would end up with birds that carry the desired traits initially found in the CX cross but the vigor and probably huge size come down to a more "normalized" result. Hopefully anyway.

But in my eyes it might take a generation or 2 of artificial insemination to accomplish the task.

To naturally inseminate an often used idea is to somewhat starve the CX roosters and even hens sometimes so their smaller structure will allow for copulation. This actually works but by starving the CX roosters you arent going to see their full potential as a breeding bird. I'm not saying one way is better than the other at this point because I havent accomplished either. Just stating the obvious that immediately comes to mind.

I also plan on using back crossing techniques to CX hens by using White American Bresse, New Hampshire Reds and Barred Rocks then back crossing each line separately through generations to CX hens until we get nice meaty yet still healthy birds. Not thinking it should take more than 2 or 3 back crossings to CX to achieve meaty birds.

At that point I would experiment with creating true breeding F4s and beyond and just keep trying to improve on those to use. Then maybe use those to cross with the CX inbred line.

Anyway there it is, all pretty much laid out. I'll try to get some pictures of the first birds I plan to use in the project. Cant do the NHs yet though because they are coming in September.

You can still find old timer Cornish Rock. I saw an ads from Craigslist recently, someone claim the stock isn't from the hatchery. I am working on the Ixworth X White Bresse project. The chicks are 1 week old and seem very active and healthy. Good luck with your project.