Breeding and Genetics

[Sawyer534]

I am just curious about dog breeding practices. How do they keep the breed lineage stable, and by that I mean do breeders ever introduce a similar breed into the mix. Or is it the same breed over and over again for purebreed dogs, I was just curious about any ill effects of line breeding. I am sure this will make sense to me after I take genetic, but I am sitting here at work and it is bothering me, and I can't find any good information related to breeding practices on the net.

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[libster06]

A "similar" breed would be cross breeding... so no, they don't do that. It's the same breed and family, over and over again. Line breeding is one step up from inbreeding, it's the mating of say a grand-father to a grand-daughter rather than a father to a daughter, etc,.... and thus is the problem with breeding in general. Selection for more homozygous traits results in narrower gene pool. This leads to breeds with all kinds of pre-dispositions to certain diseases and deformities.

As far as ill effects of line breeding? See: bulldogs, yorkshire terriers, or just pure bred predispositions for X breed. Any line bred animal (dog, horse, pig) has ill effects because rather than letting nature select for the animals, we've intervened, selecting for what we want and sacrificing other aspects (selecting for coat colors, neglecting reproduction; selecting for the largest Great Dane, sacrificing cardiac quality)

 

[Tobysgirl81]

A "similar" breed would be cross breeding... so no, they don't do that. It's the same breed and family, over and over again. Line breeding is one step up from inbreeding, it's the mating of say a grand-father to a grand-daughter rather than a father to a daughter, etc,.... and thus is the problem with breeding in general. Selection for more homozygous traits results in narrower gene pool. This leads to breeds with all kinds of pre-dispositions to certain diseases and deformities.

As far as ill effects of line breeding? See: bulldogs, yorkshire terriers, or just pure bred predispositions for X breed. Any line bred animal (dog, horse, pig) has ill effects because rather than letting nature select for the animals, we've intervened, selecting for what we want and sacrificing other aspects (selecting for coat colors, neglecting reproduction; selecting for the largest Great Dane, sacrificing cardiac quality)

Quarter horses are a GREAT study for the ill-effects of line breeding as well. Especially Impressive and Poco Bueno lines - look up HYPP and HERDA.

Anytime you have people selecting for a specific variety of traits you're going to end up limiting the gene pool and run the risk of bringing out detrimental recessive traits. I knew a very conscientious breeder of German Shepherds. She had her dogs all OFA certified. kept records of all the puppies and if any ended up with some sort of a problem (hips, elbows, etc) she wouldn't breed those parents again in the future (neutered the males, spayed the females, and sent them on to pet homes).

She'd been doing this for YEARS and started out with a pretty sizable group of breeding dogs (like 10 or so). She ended up with only 1 female whose puppies never had ANY problems. Pretty amazing when you think about it. But that's what happens when you inbreed!

 

[nyanko]

I will post more about this topic when it isn't SUPER BOWL SUNDAY WITH THE PITTSBURGH STEELERS in addition to a cardio physiology final tomorrow.

It is a topic very near and dear to me, and part of my graduate level research, so I assure you that I will be able to discuss it more coherently tomorrow.

 

[sumstorm]

I don't know about horses, but in the dog world there are times when the stud books are opened up, meaning that dogs of certain other breeds can be bred in. Generally the parent club of the breed has to desire some outbreeding, and there may be some restrictions involved.

Another option that is allowed in some breeds is the influx of foreign blood. IE the studbook will be opened to dogs registered as the same breed in another country.

But it is really breed dependent and parent club's tend to direct it.

 

[libster06]

I don't know about horses, but in the dog world there are times when the stud books are opened up, meaning that dogs of certain other breeds can be bred in. Generally the parent club of the breed has to desire some outbreeding, and there may be some restrictions involved.

Another option that is allowed in some breeds is the influx of foreign blood. IE the studbook will be opened to dogs registered as the same breed in another country.

But it is really breed dependent and parent club's tend to direct it.

So, I'm guessing that the introduction of a "similar" breed would only be whenever the breed lineage becomes unstable enough to change the genetics completely... also, just curious, but which breeds would be similar enough to cross over into each other and still get the results the breeders are looking for? And wouldn't this then not be consider line breeding, because line breeding, due to its increasing in homozygosity of offspring, is usually sure to require some kind of intervention with cross-breeding/outbreeding, in order to keep what little gene pool is left from re-breed after re-breed?

Also, the foreign blood introduction would be considered outbreeding...


So, I guess my bottom line is that it is relatively impossible to sustain a line on line breeding alone.

 

[ReadyBeVet]

I can really only speak for the breed that I know the most about, the golden retriever.

Line breeding can be very beneficial when done in the correct hands. Line breeding on one dog in particular can bring about the really fantastic traits in that particular dog and the ones behind it. Do it wrong, or on the wrong dog, and you can see undesirable traits show up in the offspring. A lot of kennels known for a "look" have done some line breeding to achieve that.

Where line breeding goes terribly wrong is in the hands of someone that doesn't know what they're doing. Someone that is breeding for "English Creme" golden retrievers. There is really no such thing. There are English goldens, bred to the standard in the UK. There are American goldens bred to the AKC standard. The "English Creme" does not belong in either. These "greeders" are breeding and line breeding on dogs for one reason, coat color. Well, everything goes to he11 when you don't breed for health, longevity, temperament. Grr.

Another issue is "popular sire syndrome" in certain breeds. One or two top winning and titled dogs sire a multitude of litters & before you know it, many many breeders are using them in their breeding program. Suddenly you have a bunch of dogs in the breed ring that are related. Not very diverse when looking for a dog with a complementary pedigree... when not line breeding.

Here is an example, Kirby, the top producing golden in breed history.
http://k9data.com/pedigree.asp?ID=19

A lot of responsible, hobby breeders will not breed to their own stud. If you think about it, it makes no sense. For one, what are the odds that you own the male that BEST complements your bitch out of all dogs in the breed? Slim to none. Someone doing this is more likely a back yard breeder, just my opinion.

Having a good database to research pedigrees and find the COI (coefficient of inbreeding) is also important for a breeder. In goldens, there is a website called www.k9data.com. It is pretty interesting to see the genetic information and the 5 generation hip/elbow clearances, search via longevity, among other things. It really allows a breeder to see what dogs are heavily influencing a litter you're planning, or to see if any other get from the sire have had success in performance venues.

 

[BClove21]

A good example of a breed who has resisted this fate is the WORKING Border Collie. If you have ever taken the time to look at more than one Border Collie at a time, you will notice there are no two dogs that look the same (for the most part). Being a working Border Collie is not "looking" like one but "working" like one. The traits that are selected for are not cosmetic, they are health, endurance, temperment, stamena, agility (not the sport...that is another convo ) bidability, conformation, and just about any other trait that makes a healthy, athletic worker. Because of this, the Border Collie has few breed characteristic diseases. Yes there are some, and that is not to say that lines have not been inbred heavily in some cases, but the majority of lines are healthy and strong. The ABCA, CBCA, and the ISDS all have very stringent policies for maintaining and introducing dogs in their registry. A dog must produce numerous proof of working ability to be accepted into the stud books if their pedigree has no recent history with the registry. Working Border Collie breeders fought long and hard to NOT have the BC recognized in the AKC because they knew it had a chance of ruining the breed and all it stands for. Unfortunately they lost and the Border Collie was accepted in, and since then, people have been breeding to AKC conformation standards and trends in the ring, and the product has sacrificed a lot of their natural abilities. That is not to say all conformation breeders do this, I personally know some wonderful breeders who make sure their BCs can still do it all, but unfortunately not every breeder believe in that. Another thing that makes working Border Collies so healthy are the breeders. Border Collies are not for everyone and most working BC breeders know this, so there is not a huge market for "greeders" as it was previously mentioned. We also all want our lines to continue to be strong, so if a potential breeding dog shows a negative trait, they are culled as far as breeding goes.

 

[StartingoverVet]

So, I'm guessing that the introduction of a "similar" breed would only be whenever the breed lineage becomes unstable enough to change the genetics completely... also, just curious, but which breeds would be similar enough to cross over into each other and still get the results the breeders are looking for? And wouldn't this then not be consider line breeding, because line breeding, due to its increasing in homozygosity of offspring, is usually sure to require some kind of intervention with cross-breeding/outbreeding, in order to keep what little gene pool is left from re-breed after re-breed?

Also, the foreign blood introduction would be considered outbreeding...

.

I am familiar with Italian Greyhounds and know for sure that outside breeds were brought in during the early 20th century (i only recall that some terriers were used but there were other as well).

Going the other way, Italian Greyhounds were also used in the Whippet line.

Foreign blood is also used all the time at least for these guys.

 

[nuevaburra]

Well, the only way to make a new breed is to cross different breeds. So all modern "stable" breeds were originally crosses of other things. And then you see new things like cockerpoos, labradoodles, puggles, which may not be AKC registered but are certainly recognized as their own categories separate from "mutts". My take is the linebreeding would depend entirely on the history of the lineage and the care the breeder takes, some breeds with notorious health problems got very popular and there was a lot of unscrupulous breeding from a relatively small stock, so inbreeding brought out undesirable traits.

As far as horses go, I have two paints, and the paint registry allows breeding to horses of other registries, either quarter horse or thoroughbred, which are compatible with the paint breed type. But I don't think they would allow, say, a shetland cross in. Horse registries in general tend to be more concerned with health than dog registries, I think, because after all most of the time the goal is to actually be able to ride the horse (halter types like quarter horses being the exception, maybe)

 

[Mama070609]

Horse registries vary a lot in requirements and rules. Some are very specific in regards to breeding and lineage, such as the Foundation Quarter Horse Registry, which requires that horses are documented to have descended from foundation stock. The AQHA is less strict with requirements, and allows one parent to be of another breed, as long as the foal being registered meets conformation and color requirements/restrictions. They do have regulations dealing specifically with horses of Impressive lineage (because of HYPP). I would have to read to re-educate myself on the specifics (the info is available online). The American Quarter Pony Association does not require knowledge of parentage. It only requires that the animal have quarter-type conformation, no excessive white markings, have no gaited characteristics, and be between 46 and 58 inches.

In general, though, horses are more widely varied within a breed than other species.

I am personally disgusted by breeding programs which take no or very little health into account. Of course, it's also important to remember that in the case of something like HYPP, there was no realization that a disease was at hand until the line breeding had been well-established. The most amazing thing about HYPP is that it was because of HYPP that the line breeding occurred. It was the disease itself that caused these horses to place so well in the halter ring. And then even after it was discovered that was a disease was causing the 'muscling', there was no knowledge of the genetic cause of it. And it took a lot of work to trace it back to Impressive. By then, his bloodline was everywhere, because he had 'ideal' QH conformation.

 

[ReadyBeVet]

Well, the only way to make a new breed is to cross different breeds. So all modern "stable" breeds were originally crosses of other things. And then you see new things like cockerpoos, labradoodles, puggles, which may not be AKC registered but are certainly recognized as their own categories separate from "mutts". My take is the linebreeding would depend entirely on the history of the lineage and the care the breeder takes, some breeds with notorious health problems got very popular and there was a lot of unscrupulous breeding from a relatively small stock, so inbreeding brought out undesirable traits.

As far as horses go, I have two paints, and the paint registry allows breeding to horses of other registries, either quarter horse or thoroughbred, which are compatible with the paint breed type. But I don't think they would allow, say, a shetland cross in. Horse registries in general tend to be more concerned with health than dog registries, I think, because after all most of the time the goal is to actually be able to ride the horse (halter types like quarter horses being the exception, maybe)

Ahh, my hot button of creating a new breed. Many people breeding crossed breeds actually have no interest in doing anything further than selling some puppies.

The problem with mixed breeds like the havapoo or goldendoodle (here I go...off on a tangent!), are that these new 'breeds' aren't using best stock possible. As someone that belongs to her local GR club, the GRCA, and shows in conformation, I know that none of the ethical breeders that I know, that perform OFA/CERF/Penn Hip/Cardio clearances would EVER give one of their quality bitches or studs to someone breeding a mixed breed. Therefore, how can you ever attain a high quality cross like a havapoo or cockapoo if you can never start with a good foundation, or at least one with proper conformation, temperament, AND health with a pedigree of those that also have all of these.

Sadly, though- these 'greeders' aren't interested in creating a new breed that will eventually be AKC registerable. They're all about making $ and churning out as many puppies as possible. Just call one of them out of your classified ad section of the newspaper. They are ready to hand over that sweet, innocent puppy if you show up with cash ASAP. Sad, but true.

 

[nyanko]

Ahh, my hot button of creating a new breed. Many people breeding crossed breeds actually have no interest in doing anything further than selling some puppies.

Acceptable crossing of breeds: you have a dog-job to do that requires a mixture of attributes found in different breeds. e.g. lurchers

Unnecessary crossing of breeds: to make a profit off of your "really sweet" Labrador Retriever and your neighbor's "really smart" Poodle.

edit: if they wanted to make a new breed, they would not be churning out so many first generation crosses of the same two breeds.

 

[No Imagination]

There is talk (among the AKC) of introducing some German Short Tail Pointer blood into the Dalmatian blood line to help reduce/eliminate? urate uroliths (their purine metabolism problem).

 

[BClove21]

Ahh, my hot button of creating a new breed. Many people breeding crossed breeds actually have no interest in doing anything further than selling some puppies.

The problem with mixed breeds like the havapoo or goldendoodle (here I go...off on a tangent!), are that these new 'breeds' aren't using best stock possible. As someone that belongs to her local GR club, the GRCA, and shows in conformation, I know that none of the ethical breeders that I know, that perform OFA/CERF/Penn Hip/Cardio clearances would EVER give one of their quality bitches or studs to someone breeding a mixed breed. Therefore, how can you ever attain a high quality cross like a havapoo or cockapoo if you can never start with a good foundation, or at least one with proper conformation, temperament, AND health with a pedigree of those that also have all of these.

Sadly, though- these 'greeders' aren't interested in creating a new breed that will eventually be AKC registerable. They're all about making $ and churning out as many puppies as possible. Just call one of them out of your classified ad section of the newspaper. They are ready to hand over that sweet, innocent puppy if you show up with cash ASAP. Sad, but true.

Like Like Like...oh wait, I forgot we arent on facebook

 

[nyanko]

There is talk (among the AKC) of introducing some German Short Tail Pointer blood into the Dalmatian blood line to help reduce/eliminate? urate uroliths (their purine metabolism problem).

German Shorthaired Pointer ? That was already done years ago and the Dalmatian club won't register offspring from the experimental crosses. I have worked extensively with the geneticist who discovered the gene responsible for hyperuricosuria/hyperuricemia in Dalmatians. She actually used to breed them and moved on to a different breed.

Here is the backcross experiment they did with the Pointers to map the locus originally.

 

[awaring1]

Horse breeding can be very complex. Super super simple terms:

Breed Registry is "closed book": Horses registered within the breed can only produce registered offspring if bred with another registered horse of that breed. This is confirmed with DNA testing.

Breed Registry is "open book": Registered horses within the breed can be bred to horses of other (approved) breeds and the offspring can be registered with that same breed. (The Morgan book was open to saddlebreds and such for a while... bred the brains right out of them. Almost destroyed the breed in my opinion)

Warmbloods: F'in crazy. There is no simple answer. Some horses can be born into their breed, some can be accepted if they meet physical standards, some have to take a 100 day test and be "aprooved." aye aye aye...

And then you have your registries for the "half-bred" and there are some breed organizations that let you in as long as you are half that breed. Its a hot mess pretty much.

Just remember: A horse is a horse, of course of course, unless that horse has a mixed linage and can still be registered with three different registries.

what... what?