Dumb Question About Genetic Diversity

[speckledhen]

NYReds is absolutely correct. He knows what he's talking about on this subject, trust me. There is more to linebreeding properly than most folks understand. And if you cross two different strains/lines, you have no idea what that combination will do. It could be very, very bad or very good. And you won't know until you do it and see what happens over time.

I encountered dwarfism in my Delawares, not the kind where the bird is just small, but where it has a parrot beak, short legs, crooked toes and dies at a young age. I have since sold the hen responsible, but only after actual genetic testing of one of her daughters confirmed that she carried a double dwarf gene, something many don't even know exists. To look at her, you'd never suspect and to see her big, chunky daughter, you'd be hard pressed to believe she carried a double dwarf gene. There had never been any previously known, but there it was, staring us all in the face. So, you just never know what happens when you cross two different lines for the first time.

 

[Ryu]

Without having pedigree information or any kind of genetic tracking, it's really hard to comment on the state of genetic diversity in chickens without some kind of genetic testing.

The truth is, we don't really require a lot out of Chickens. Chickens just have to give the appearance of health, grow feathers, and reproduce. They withstand inbreeding and linebreeding better than most other species I've worked with.

If you don't have a roo, then you're going to need to pick one up anyway. There are other threads on setting up various breeding schemes (Spiral, Braid, In/Linebreed), my advice is to pick one, stick with it, and cull. Keep an eye out for problems and your flock will be fine.

 

[Sonoran Silkies]

Quote:
I personally do not know dog genetics, but I have seen comments written by those who are knowledgeable of cat, dog and horse genetics who have said that chicken genetics are far more complicated. Chcikens and dogs do have the same number of chromosomes: 39 pairs.

 

[Ridgerunner]

I am not anywhere an expert on the genetics of chickens. I'm just somebody trying to maintain a sustainable flock with the main goals of them doing a lot of free ranging, breed my own replacement layers and roosters, going mainly for meat but with egg production reasonably important. A broody would be nice too but I know I'll be running the incubator a couple of times a year. I'll give my opinion and hope to get corrected where I am way off.

I'm sure there are different business models for the hatcheries. Some probably keep their own flocks or have exclusive agreeements with people for hatching eggs. I suspect a lot of them buy hatching eggs from the same flock, especially for some of the rarer breeds. There is always a chance that you can get full blooded brothers and sisters from a hatchery, but I think the odds of you getting closely related chicks from a hatchery are pretty slim. They hatch out a lot of eggs. They keep one rooster for every ten hens. You are probably OK as a starting point with stock all from the same hatchery. If you are really concerned about them being inbred, start with a mix of breeds. Unless I misread your goals, mutts should do you just fine.

If you are going to go for a sustainable flock without adding outside blood, you need to learn a lot more than I know about genetics and what you are looking for. Since you are not showing, color of the legs or number of points on a comb are not important to you. I'm guessing egg production and probably meat are important. Also important are them staying healthy, that they lay fertile eggs, and don't develop any deformities that interfere with your goals or their ability to sustain themselves. To achieve this, I think you are going to have to hatch out a whole lot of chicks and cull mercilessly. You are going to have to keep a fair number of chickens to form your breeding stock. Keeping one rooster and ten hens won't do it. I don't know what the magic numbers are, but you need enough diversity in your breeding stock to weed out bad traits if they show up. Unless you seriously get into it, I think you are going to have to add outside blood fairly regularly.

I don't know what fairly regularly will mean to you. It will depend on how good you are at culling, how many chicks you hatch every year, how big your flock is, and somewhat how lucky you are in what you hatch. I like to add by getting hatching eggs and raise my own. I think getting NPIP certified hatching eggs is the safest way to add to the flock from a disease perspective, but there are plenty of other options.

You can get hatching eggs or new live stock many different ways, hatcheries, neighbors, people on this site, chicken meets, chicken shows, Craigslist, whatever. To me, probably the best way is to get eggs or chicks from a breeder. I have a tremendous amount of respect for the true breeders, the ones that put a lot of time, effort, and money into achieving their goals. But not all "breeders" are created equal. Some people will buy a bunch of chicks from a hatchery and sell the offspring as pureblooded chickens. Those are no better than hatchery chicks and may be worse if they don't know what they are doing or don't hatch out enough and cull properly. Some people are developing lines that are not in any way related to what you are trying to do. I met someone a couple of years ago that was trying to develop a line of chickens that has an extra toe. One of his chicks hatched with an extra toe so he thought it would be cool to develop a line with an extra toe. He also has some lines he is trying to breed to the standards and he is trying to develop some different colors. Someone breeding to standards and trying to develop a grand champion may not be your best bet. To them, the sharpness of the feather pattern is probably more important than how well they lay eggs. Many times, chickens bred to standards are going to be superior to hatchery chicks, but not always. It depends on your goals. If eggs are your sole goal, hatchery chicks have been bred with eggs in mind. I think getting hatching eggs from breeders is the best way to improve your stock, but you need to talk to the breeder and let them know what your goals are. The good honest ones will tell you if their line of chickens will help you meet your goals.

These are some of my thoughts on getting and sustaining a flock. I'm no expert but maybe you can get something helpful from this.

 

[Ryu]

I think that chicken genetics appears to be more complicated because there isn't a pedigree or registration process--breeders are free to cross and out-cross at will. How many of us really ask about the breeders program when we buy a bird? I think you'd be really hard pressed to find a lot of flocks that are 8-15 generations pure--especially for color variety.

I haven't really noticed any difference in heritability between Horses, rabbits, or mice. Chickens have more color varieties and patterns than most other species--and that's just fun more than anything. If we had 100+ years of ped info on chickens like we do on horses, there wouldn't be very many surprises.

It's one of the things I enjoy about breeding chickens after all the paperwork and restrictions, you never really know what anyone else is up to and you are free to do the same. Outwit, outsmart, outplay--Chicken Survivor!

 

[SkyWarrior]

Wow, I am getting some very thoughtful replies. I'm pretty savvy at understanding the basics of genetics and understand the different forms of linebreeding/inbreeding etc. I forget that with chickens we can cull defective birds pretty easily without the same emotional attachment we get with dogs and that the chicken produces a viable egg a day if it's fertilized, whereas realistically one shouldn't breed a dog more than once a year or every two years. Different issues and scale.

That's really interesting about the outcrossing because in other critters, you want outcross to ensure you're not getting what speckledhen experienced. But this kind of thing can happen with outcrosses too, so go figure.

NYReds has some very good thoughts and I think Ridgerunner has summed up my position pretty close. I'm not sure if I want to go the mutt route, but I'm not looking for show birds either and eggs are important. I haven't put any of my own eggs in the incubator yet because I don't want the hatch they'd produce.

If I were to sell chicks, I would try for a nice purebred stock, EE or maybe even an OE that people around here couldn't get from the feed store, but certainly wouldn't worry about show quality. I'm partial to the blue breeds because they're so unusual around here and to my surprise I actually got a blue marans chick out of the last hatch.

So, in your opinion, are show lines less likely to be good egg layers?

 

[speckledhen]

That's really interesting about the outcrossing because in other critters, you want outcross to ensure you're not getting what speckledhen experienced.

Actually, it may be the outcross that made factors come together to produce the dwarves. Or maybe it wasn't. Hard to say since that was back before I had that particular hen, but you never really know what two different lines will produce when you cross them.


I had Rhode Island Reds from show lines. They were fabulous layers. My Ameraucanas came from show lines and are also great layers. I've had some say the BR show lines don't lay as well nor are they as friendly, but I don't have experience with those. Guess it depends on if the show lines pay attention to the egg laying consistency as well as looks.​

 

[Ryu]

Outcrossing doesn't really solve the 'Rats, I've got a recessive genetic disorder' problem. If you keep outcrossing, you never know what you're breeding into. There is a chance that you may be introducing more undesirable genes as well as beneficial.

There's a balance between maintaining the genetic vitality of your flock and creating realiably reproducible phenotype. That's breeding programs like the Spiral or Braid try to achieve.

I hatched some Blue and Olive egg laying hens this year just because I like color in the egg basket--but I find my pure breds to be more rewarding.

The most important thing is that you like the birds. If you like the Blue Marans they lay a lovely egg, good size and pretty color, and meat-wise they fill out pretty fast. We took a few to the processor last year, and they were just about like all the other non-cornish birds.