Question on Breeding chickens.

[alexa009]

This may sound a bit complicated but have a pretty important question that I would like to understand. If a female chicken comes from the same mother and father as the male which would make them brother and sister could they mate and let the baby chicks hatch? I know this can't take process in goats, dogs etc.. I am just wondering if it is different with chickens. I would just like to know. Thanks!

 

[Ol Grey Mare]

Yes, it can be....and frequently is.....done. the concentration of genetics can maintain desired traits, but can also serve to amplify genetic faults of tthe line.

 

[RiverOtter]

Just so you know, it most certainly can take in goats, dogs and everything else.

The only reason it is not done is 1)Because most humans have an innate inhibition against inbreeding (compared to most animals, humans are all very highly related - any 2 random humans on earth are more genetically similar than any 2 random Golden Retrievers) and
2) There is a concentration of traits, and if you start out with not-great genetics, you'll get more of that. For instance, if your dog and it's brother both carry the gene for dwarfism, bred together they are way more likely to produce dwarfed pups (often fatal in dogs) than if you bred them to another random dog who may or may not carry the gene.
But they're certainly fertile together!
And where the genetics are known, people actually do this all the time

 

[Egghead_Jr]

In a nutshell, "inbreeding" is if you breed too closely for too many generations it will lead to loss of vigor in the birds. Hatchability of eggs will be the first sign of need for infusion of new blood. Line breeding is managed breeding of close relations to narrow in on desired traits and maintain genetic diversity.

Mating of brother and sister is not the most desired breeding path. Pullet backcrossed to sire or cockerel backcrossed to dam is typically the way to go. By breeding in groups, i.e. daughters to father, sons to mother, grandson to original dam, daughters to uncle and so on, you can track your birds and gene pools. By not going down a singular path of genetics you can maintain diversity and keep records of it in your flock.

By breeding siblings you really don't know how much genetic material is coming from the original parents. By selecting for your personal preference of breeders or standard of perfection criteria that could be your selecting birds that carry most of the traits of one original bird. Not that this is a bad thing but you can't track and record it. There is no means to say this third generation has X amount of original dams genetics and Y amount of original sire genetics. As each generation it taking 50/50 from each parent but with continued sibling matings that does not result in 50/50 original genetics. Probably not explaining that well. We know first offspring is 50/50 but second generation (if brother sister) can be 75/25 to 25/75 genetic material and generation after that 87.5/12.5 to 12.5/87.5. Quite a range of unknown genetic material percentage trending there.

Reasons not to breed siblings are what's stated above and it's not the fastest way to set a desired trait. Say the dam was exceptional specimen to the standard of perfection and the sire was merely good enough. Well, backcrossing the son to mother would be the way to carry more of her desired traits into the offspring. Crossing brother to sister will throw chicks with a wide range of characteristics. You've got to hatch a lot more chicks from this mating to get any decent number of better birds. But the better original parent breed to best few offspring increases your chances of better traits in chicks as it's narrowing the gene pool. This is a good thing and how all these breeds were created and improved on to begin with.

Now I don't want to omit sibling matings completely. They do have a role. Say you've parent stock from different lines. To create a new line you breed the F1 brother/sister generation together to beget F2, that generation mated together begets F3 and so on. By F3 with rigorous culling you'll have set the traits in that line. The offspring will be more consistent in traits. Your creating a new line of birds. F1 birds have all sorts of varying genetic material brimming over with potential. People usually stop at F5 generation, rigorous cull and narrowing the traits will have greatly narrowed the gene pool by then.

To make this post really winded I'll tell you what I'm doing and why. I crossed two lines of birds (from different origins). The male was a very good specimen but didn't like the line he came from in general. Stupid of me to cull him after mating as he really was a good bird and yet to get back to his size though he did have a fault from that line. So with no genetic material of him and that line other than his offspring I'm making F generations in attempt to gain back his size and body type without the bad trait he carried which was red feathers. Just set up the breeding pen with F1 birds to make F2. Later this spring will put an F1 cock in a pen with a few of the original dams. By creating two branches that will fork in later generations I'll maintain genetic diversity for over a decade. The F generations will have breeding pressure for size and the matings back to original dam and forks of those generations will maintain the color and type of the breed. By breeding in groups I know who came from where and with that maintain diversity yet still narrowing and improving on desired traits.

 

[Mosey2003]

You can breed full siblings, yes. Personally, I'm okay with it if the parents aren't closely related. If you're working towards a specific trait or set of traits and want to concentrate that, it will work. But when you really get into linebreeding and inbreeding, you have to be willing to cull anything that isn't up to par and you need to have a plan for further down the line. You definitely can run into problems if you keep at it too long.

 

[alexa009]

Just so you know, it most certainly can take in goats, dogs and everything else.

The only reason it is not done is 1)Because most humans have an innate inhibition against inbreeding (compared to most animals, humans are all very highly related - any 2 random humans on earth are more genetically similar than any 2 random Golden Retrievers) and
2) There is a concentration of traits, and if you start out with not-great genetics, you'll get more of that. For instance, if your dog and it's brother both carry the gene for dwarfism, bred together they are way more likely to produce dwarfed pups (often fatal in dogs) than if you bred them to another random dog who may or may not carry the gene.
But they're certainly fertile together!
And where the genetics are known, people actually do this all the time

Yes, I knew they were still fertile I just thought inbreeding was dangerous and can lead to problems. Thanks so much for your info also!

 

[cgmccary]

Yes, it can be done and is commonly done. The genetics good and bad get amplified as has been aptly described above. As a practice, I do not breed siblings.