Please Note: The following article is reprinted with permission in its entirety from Gary Hutchison of Westwind GSP's and may not be reproduced elsewhere. The original article is available at www.westwindgsps.com/linebreeding.htm.

Understanding Linebreeding

A very liberally edited version of an article by Jerold S. Bell, D.V.M. that appeared in the September 1992 American Kennel Club Gazette, "The Ins and Outs of Pedigree Analysis, Genetic Diversity, and Genetic Disease Control" ... followed by some personal observations.

Without exception all breeds of dogs are the result of inbreeding. Inbreeding has either occurred through natural selection among a small isolated population (i.e. the dingo) or through the influence of man breeding selected animals to derive specific traits. Either way intensive inbreeding is responsible for setting enough of the dominant traits that the resulting group breeds true to type. At which point a population of dogs can be said to be a breed.

Dogs actually have more genes than humans. Tens of thousands of genes interact to produce a single dog. All genes are inherited in pairs, one from the sire and one from the dame. If the inherited genes from both parents are identical they are said to be homozygous. If the pair of inherited genes are not similar they are said to be heterozygous. The gene pairs that make a German Shorthair breed true to type are obviously homozygous. However, variable gene pairs like those that control coat color, size, scenting ability, etc. are still heterozygous within the breed as a whole.

Linebreeding concentrates the genes of a specific ancestor or ancestors through their appearance multiple times in a pedigree. When a specific ancestor appears more than once behind at least one animal on both the sire's side and yet another animal on the dame's side homozygosity for that animal's traits are possible.

However, if this specific ancestor appears only through a particular offspring of the ancestor in question then the Breeder is actually breeding on this offspring of the ancestor rather than on the ancestor itself. This is why having many "uncovered crosses" to a specific ancestor ( those that come through different offspring of this specific ancestor) gives the Breeder the greatest chance of making the desired traits of the specific ancestor homozygous.

Homozygosity greatly improves the chances that the resulting pups will in turn pass on the desired traits of the specific ancestor to their pups. When selecting pups from a line breed litter the Breeder must choose pups that display the desired traits of the specific ancestor or they have accomplished little. In fact, if these traits are not present in a linebred pup it is very likely that it inherited its genes from the remaining part of its pedigree and will be unable to breed true to type. Because the Breeder selected “out” for the pups that didn’t display this original ancestor’s traits.

Inbreeding significantly increases homozygosity, and therefore uniformity within a litter. One of the best methods of evaluating how successful a linebreeding has been is to gauge the similarity of the littermates as compared with pups of other litters with similar pedigrees. Considerable similarity among littermates tells the Breeder the genes have "nicked" or paired together as anticipated. The resulting pups will likely be able to pass these genes to the next generation.

Undesirable recessive genes are always masked by a dominant gene. Through inbreeding a rare recessive gene can be passed from a common ancestor on both the sire and the dame's side creating a homozygous recessive offspring. The resulting offspring actually displays the trait neither of their parents displayed ( even though both of them carried it ). Understand that inbreeding does not create undesirable genes it simply increases the chance that traits which are already present in a heterozygous state within the breed will be displayed.

Too many Breeders outcross as soon as an undesirable trait appears, blaming the problem on breeding "too close." Nothing could be further from the truth. In fact out-crossing insures that the undesirable trait will be carried generation after generation in a heterozygous recessive state only to rear its ugly head again and again. Therefore the Breeder who turns away from breeding “close” is simply passing a known problem on to succeeding generations and future Breeders.

When an undesirable trait is "unmasked" the Breeder who does his breed a real service is the one that stays with his line long enough to rid it of the undesirable trait. By controlling which specimens within their line are used for breeding in succeeding generations this Breeder can eliminate the undesirable trait. Once the recessive gene is removed it can never again affect the Breeder's line. Inbreeding doesn't cause good genes to mutate into bad genes it merely increases the likelihood that they will be displayed.

The Inbreeding Coefficient (or Wrights coefficient) is an estimate of the percentage of all variable genes that are homozygous due to inheritance from common ancestors. It is also the average chance that any single gene pair is homozygous due to inheritance from a common ancestor. Our pedigrees display the Inbreeding Coefficient for each dog in the first 4 generations of a specific dog's ancestry. Each Inbreeding Coefficient is calculated from that dog's 10 generation pedigree.

Note: Inbreeding does not cause good genes to somehow mutate - it only increases the likelihood that existing genes will be displayed - allowing the Breeder the chance to eliminate what had previously been unseen in their particular line although it was always present.

At Westwind GSPs we gauge the amount of homozygosity in an animal using their Inbreeding Coefficient (or Wrights Coefficient) - which can be seen as an estimate of the percentage of all variable genes that could be inherited from common ancestors. It is also give us a mathematical value for the average chance that any single gene pair is homozygous due to inheritance from a common ancestor.

Our pedigrees display the Inbreeding Coefficient for each dog in the first 4 generations of a specific dog's ancestry. However, the Inbreeding Coefficients displayed for each dog in our pedigrees is in turn calculated from that particular dog's 10 generation pedigree. We can trace most of our dogs back more than 20 generations – some as far back as 35 generations.

Our German Shorthairs

Four generation pedigrees that contain 28 unique ancestors for the 30 positions in the pedigree would obviously generate a low inbreeding coefficient. Yet a ten generation pedigree for the same dog might look quite different. If this dog were to have say 700 unique ancestors filling the 2048 positions in the pedigree the results for the same dog would be a much higher and truer inbreeding coefficient. Sometimes what appears to be an out-bred mix of genes in the first few generations (especially with owners naming their own dogs) ends up being a fine example of linebreeding when the pedigree is extended.

However, it must be remembered that simply knowing the inbreeding coefficient of a dog does nothing to help us understand which ancestors the dog is actually bred on. We know that the animal in question has many crosses to the same ancestors but we don't know which ancestors they are. To understand this, and to unlock the secrets of a dog's pedigree, we must do a homozygosity study.

A homozygosity study is not a percent blood calculation. The percent blood of a dog and its immediate ancestors is relatively easy to estimate but not that important. In fact the dog will have 50% of its blood be from it sire and 50% of its blood be from its dame. But if these two dogs have no common ancestors the inbreeding coefficient would be 0%. Homozygosity is far more important in determining what traits a dog is capable of passing on to its offspring than percent blood but it is extremely difficult to calculate without the use of a computer.

So while knowing a dogs inbreeding coefficient is important in accessing its potential to throw its type we still need to clearly understand which dogs behind a particular dog are the most influential. Simply knowing how homozygous a particular animal is does nothing to help the conscientious Breeder understand this. To understand this and to unlock the secrets of a particular dog's pedigree we must do a homozygosity study. We need to know which ancestors the dog in question is bred on.

On more than one occasion we have seen pedigrees in which the most influential ancestor for a homozygous trait doesn't even appear in the first three generations. In this type of situation it is not unusual for this particular ancestor to contribute 50% of the homozygous genes of the dog in question. In this case if a dog is 16% inbred one ancestor would be responsible for 8% or 50% of the dogs homozygosity. It is of paramount importance for the dedicated Breeder to know not only the inbreeding coefficient for the resulting litter before the mating is done but also which dogs in the pups pedigree are influencing their genetic potential.

Far too many matings have been done only on the basis of physical appearance with little if any regard to the sire's and dame's respective pedigrees or the interplay between the two. Novice Breeders don't realize that individual dogs may share desirable traits but inherit them differently. This is especially true of polygenic traits, such as ear set, bite, or length of forearm. And many Breeders fail to understand that breeding dogs which are phenotypically similar but genotypically unrelated won't produce the desired traits in the current litter - and will actually reduce the chance of these traits being reproducible in the next generation.

Conversely, individual German Shorthairs with the same pedigree do not inherit exactly the same genes and will not breed identically. Dogs in a litter are no more similar than brothers and sisters in a human family. Think about it. If dogs have more genes than people and they are as dissimilar as human siblings need we worry so much about the “too close” we hear sounded by all those who know little or nothing about linebreeding. At Westwind GSPs we regularly breed litters with a Wright’s Coefficient of more than 20% with superior results. There have been examples in German Shorthairs of fine animals with inbreeding coefficients as high as 65%.

The secret is that all linebreedings must be made on a combination of performance, appearance and ancestry. If a Breeder is going to be successful in solidifying a certain trait they must rigorously select breeding specimens which display the desired trait and have similar pedigrees. In so doing Breeders have a chance of making this desired trait homozygous over time. This is the one key to successful linebreeding that is most often missed by unsuccessful Breeders.

In choosing a line of dogs within any bred it is wise to choose a line with "critical mass". Find a line within your breed where the most prepotent individual was mated many times and produced many superior offspring. Without enough genetic diversity it will be more difficult to find animals within the line that do not also share the faults of the pre-potent individual. These are the faults the Breeder will have the most difficulty in eliminating.

No matter how limited the critical mass the Breeder must never breed animals that are poor examples of what the Breeder is trying to produce simply because they share common ancestors. Breeding “paper” is the quickest way to ruination and is largely responsible for the negative attitudes people have toward linebreeding. To a Breeder no dog is worth more than what it is able to produce. No amount of titles can overcome an animals inability to reproduce its own great traits. Look at the lack of production from Secretariat.

Most beginning Breeders suspicion they should start with a brood bitch of a particular line and they are correct. If at all possible the new Breeder should obtain females that come not just from the same important stud but actually come from the same Motherline that is behind the stud in question. Instead of trying to get a bitch as close to the stud in question look for a pedigree in which the mothers of the sires are themselves from the same genepool. This is the female who will likely produce great pups.

Motherlines in German Shorthairs

In all mammals the females are "X" "X" and males are "X" "Y" which means that only females carry the genetic code particular to the part of the gene string that is missing in all males. Horse Breeders refer to it the "X Factor" and have demonstrated that the gene responsible for the large heart so many great racing stallions have can be traced back thru their motherlines to a single mare that lived more than 100 years ago. If a stallion has an oversized heart - like Secretariat - this particular mare will show up in his motherlines over and over again. The mares themselves don't have the large heart but they carry the gene for it on their “X” chromosome. Like wise the stallions do not throw the large heart themselves.

And so it is with German Shorthairs. The bitches are far more important than the studs in carrying particular genes forward. Understand that this is true even if the genes most sought were originally found in a pre-potent male. The key for any successful Breeder is to isolate those females that carried his traits and breed off of them. It has been our experience that many important traits are indeed sex linked and carried by the dames from generation to generation.

Successful Breeders realize they are fighting "the drag of the breed," which is the tendency for all animals to breed back toward mediocrity. If it didn't work this way super species and super races would have developed long ago in every animal on earth. For instance in human beings it is impossible to breed parents with high IQs together to produce higher IQs. Even when two genius have children the average IQ of their children will be half way between normal and the average of their IQs.

By the way Einstein himself was the off spring of parents who were themselves first cousins - and he married his first cousin. So much for the tails of woe you heard in school about the effects of inbreeding. In fact the history of the German Shorthaired Pointer is replete with many examples of intensive inbreeding that produced some of the more influential dogs in our breed.

A History of German Shorthairs

Unsuccessful Breeders regularly overlook an animal that has a great trait because it also has a minor fault in favor of an animal that has no faults but no great traits. Successful Breeders use specimens within their line that have at least one truly great trait and breed them with specimens that in turn are great where the other dog is weak. This is the "secret to line breeding" - the only way to successfully fight off the drag of the breed.

In so doing it is possible to linebreed offspring that are better than both the sire and the dame. Mathmatically fully ¼ of the resulting pups have the possibility of getting the great traits from both parent. Plus, the resulting specimens in turn can pass these great traits on to the next generation, unlike the F1 hybrid animal that results from outcrossing that carries the same traits. This is how a successful Line Breeder can actually improve his line as he condenses his gene pool.

So much is made about the perceived problem of a limited gene pool in pure bred dogs it has caused some "experts" to advocate out-breeding of all dogs. However, studies in genetic conservation of rare and endangered species have shown this practice actually contributes to the loss of genetic diversity. If we were to uniformly out-cross all "lines" in any breed we would eliminate the differences between the lines and therefore reduce the diversity between individuals within the breed. The process of breeding toward genetic purity of any particular line of German Shorthairs will in fact contribute to genetic diversity within the breed itself.

In fact what few people understand actually happens is that as a line is successfully bred over the years a concentration of good recessive genes is happening. Assuming the Breeder is a person of integrity and doesn't knowingly breed animals that have disqualifiable faults or traits. Over a period of time this Breeder will clean up his genepool. While it is true that linebreeding gives the opportunity for the worst traits to display themselves in any individual animal, it is not true that the Breeder is required to use that animal in his genepool. In fact if the Breeder is concerned with his genepool and not just about producing pups he actually has the opportunity to clean up genes that would go unnoticed in an outcross breeding.

What actually happens in a successful linebreeding program is that over the years the dominate genes in the line tend to lessen in number. This is because unless a dominate gene was selected out for in each successive animal it can never "reappear" in the same way that a recessive gene can. Obviously if neither of the parents displays this dominate gene then none of the offspring can - because it no longer exists in the genepool.

Dominant genes are either displayed or they don't exist. And it should be noted by any serious Breeder that the "Original Animal" his particular line was built on was the only animal in his line to carry all of the dominate genes originally possible. From that point in a truly closed breeding program there is only the chance that the number of dominate genes will decline as they are slowly being replaced on each point of the gene string by recessive genes. There is no other possibility unless a breeder outcrosses.

Therefore if the Breeder isn't skillful in accessing and selecting offspring they will lose some of their precious dominant genes over time. Often we hear Breeders say they are “needing an outcross” - what they are really saying is that they have lost their original dominant genes and have no other means of getting them back. These could be some of the most cherished traits of the Fountainhead Animal.

If possible it is wise for you as a lineBreeder to freeze semen on old stud dogs in your genepool who are known to throw the dominate genes you value. This gives any Breeder the ultimate insurance policy - the ability to "outcross" within their own genepool if they were unfortunate enough to lose valued dominant genes over time. We have made good use of frozen semen on a number of occasions.

Our GSP Puppies

One of the more interesting things about a linebred genepool is that it is difficult if not impossible to pass a linebreeding program on to another Breeder. Lets assume that you have put in the work and made the difficult decisions not to use certain specimens (even those with highly touted titles and awards) because they pass on undesirable genes. Let's assume you have managed to clean up your genepool. At the point another Breeder is lucky enough to bred to some of your best specimens it will improve virtually anything the other breeder has.

Unfortunately, while those who outcross to your line will improve their genetic structure the genes of your inbred line will tend to vanish because these genes will very likely be more recessive than the outcross genes. In effect the outcross genepool will "cover up" your more recessive inbred genes. And there is not much either breeder can do about it - even if you wanted to. Unfortunately many breeders do this to themselves.

We have seen this many times over the years especially from those who think they can "buy their way in." The fallacy in their thinking is that they can buy a line breed brood bitch from one line and a line bred brood bitch from yet another line to breed to their great new Stud Dog – often their first German Shorthair. They think they can start a breeding program overnight from three different genepools because the dogs are such fine specimens. Oh if it were so simple.

Often overly enthusiastic newbies in their over simplified thinking take this exact approach. Unfortunately, it is the third generation where the wheels come off. Why the third generation? Well the first two liters were dynamite because they were both F1 hybrid liters. But when the F1 hybrid offspring from one linebred bitch are bred to F1 hybrid offspring of the other linebred bitch things come apart. In fact this "well laid plan" is a sure receipt for breeding straight downhill.

So what is the answer? Wherein lies the truth? It is not what you want to hear but here it is: Years and years of line breeding by a committed ethical Breeder - someone with a vision of perfection and the tenacity to make difficult decisions. The only way to consistently produce superior animals is to linebred. Period ... it’s that simple!

Those who argue against linebreeding are inevitably those who have never successfully bred animals themselves - most often they are college professors. The same people who have bred nothing more complicated than fruit flies or no more demanding than lab rats are often the most vocal about how others should breed performance animals. These "know-nothings" advocate the notion that out-crossing is in and of itself good because it produces some thing they often refer to as "hybrid vigor".

To them, and to you, we pose this question: "If out-cross breeding is the answer then why don't the owners of successful herds of Holstein milk cows out-cross to the American Shorthorn milk cow?" In theory this would produce super milk cows by combining a milk cow that has the genes for high milk production like the Holstein with one that has the genes for high milk quality like the American Shorthorn. Oh yes on both paper (the stuff of academia) and in theory this should produce the best milk cows on earth.

But this is where the theory that reigns supreme in the professor’s lab meets the reality of the milk barn. Some of the most inbred animals on the face of the earth are Holstein Cattle. The reality is that dairy farmers know all too well is that they would go broke from the inferior milk production of the resulting out-crossed animals. Crossing to an animal with such poor milk production would be disastrous fore them. And here in lies the rub for all of us ...

Understand something and don’t let anyone sway you again. Outcrossing does NOT produce “more” – the genetic material remains the same. Nor do the qualities of the subject animals it produces multiply. Just as linebreeding doesn’t damage genes - outcrossing doesn’t magnify what’s in the genome. There is no magic in out crossing!

Note: So called "hybrid vigor" is never in and of itself the answer to breeding better specimens. The quality of the specimen used in any breeding is far more important than whether or not a particular animal has a very low inbreeding coefficient or whether the proposed breeding will result in a low inbreeding coefficient.

And for those who continue to stubbornly advocate outcrossing we ask you this final question: "Even if by random chance the outcross breeding in question would actually produce a superior specimen would the animal in question be able to reproduce itself? Would the greatness be passed on to its get?" No.

The sad fact is that this superior specimen would likely not be able to reproduce itself. It will likely never throw a single specimen as good as it is in its lifetime. This is because by definition this “super specimen” is of the F1 generation. And animals of this generation are rarely able to reproduce themselves. So what has been accomplished by even a successful outcross? Little or nothing other than to put a single animal on the ground.

For fun I would like to invite this no-nothing college professor to the race track where for an afternoon he would have the opportunity to bet on all the outcrosses and I would bet on all the linebred race horses. I believe we call them Thoroughbreds for a reason don’t we? Oh but I forgot he wouldn’t be the betting kind would he? Not in his lifestyle and not in his career. No, he would be the man of theory. He would be a man who lives in the world of theory.

Not us my friend! No, we both live in the world of fact. Yes, we live in the world of bird hunting where what separates the wheat from the chafe are immeasurable traits like “heart” and “bird sense”. At Westwind GSPs we understand how much is expected of these amazing athletes we call German Shorthaired Pointers. You see we own performance animals not lab rats.

Think about it. Those who advocate the outcrossing of birddogs are effectively proposing that bird hunters entrust the development of their performance dogs to the whims of random chance. If you believe this is a wise course then you need to locate another Breeder. May we suggest that you check the want ad section of your local newspaper where you will find many splendid examples of outcross breeding.

Successful linebreeding is a long and arduous task - one that requires a lifetime's commitment to a particular line of dogs. We have great respect for the few Breeders of German Shorthairs who successfully developed and perpetuated their particular line of GSPs in the past – fighting negative public opinion all the way. Even if we don't have a single dog from their particular line in our pedigrees we have studied their breeding patterns and over the years have developed a deep appreciation for their work.

It is from the legacy of Breeders who refused to settle, who held to their standards when things didn’t go as planned that we owe so much. It is from those Breeders who bred to the brother of the champion because he produced better pups than the titled dog that all of us enjoy a robust GSP gene pool today. To them we all owe a huge debt of gratitude.

Our Breeding Philosophy for German Shorthairs

Although our breeding program remains a "hobby" our commitment to the German Shorthaired Pointer remains strong. We are looking forward to many more fine litters and many more years of great hunting behind our beloved Westwind GSPs. Which remains the single driving force behind our breeding program. Good Hunting.