Scot E. Dowd Ph.D.

First lets define what Linebreeding is NOT:
Line breeding has nothing to do with a kennel name
I have seen dogs that were said to be line-bred that had no shared ancestors in a 5 generation pedigree. But many of the dogs had the same Kennel Name affixed to their registration.
 
Linebreeding is: A breeders tool used to develop, isolate and set specific desirable traits into succeeding generations. Line breeding can be seen in registered dogs by having specific high caliber or quality ancestors two or more times in the recent pedigree as noted in introductory chapters.  Line breeding often has more than one high quality ancestor multiple times in the same pedigree. However, from a purely scientific point of view, linebreeding can also be defined as breeding two individuals containing at least one common ancestor. This common ancestor may contribute a negligible amount to the descendants, or a great amount. This makes the scientific meaning lacking in true art and practice. You can do a linebreeding that has absolutely nothing to do with refining or setting specific traits or you can practice the art and craft of breeding better animals and make rational choices in your program.

Ultimately, linebreeding is simple concept that is extremely complicated as a breeding tool.  One must remember that linebreeding is a program that produces animals from a single line of descent from a common or a few common and outstanding ancestors. The goal is not to reproduce the quality of the ancestors but to try maintain as many of their good qualities as possible while improving their deficiencies by refining the genetics of the line. If you know a breeder that is producing the perfect animals then why the hell do you need to breed? Just buy all your dogs from this breeder. If a breeder is producing superior dogs and you breed off their lines will you produce better dogs than that breeder? If not then do the breed a favor and do not breed.

OK so to repeated using different words line breeding is a popular but often abused or misused tool for maintaining “type” but should only be used when attempting to refine phenotypic characteristics in the APBT. The hobby breeders make use of this tool often without knowing what they are doing, maybe because they prefer a certain look and will select foundation dogs from breeders whose lines have this specific look or color. Unknowingly, they then begin linebreeding. Others may be mentored by an established breeder and become an extension or tool of that breeders program goal. In my case I have established partnerships with other kennels and we have joined together with a common vision and defined the goals in our breeding program and work together to achieve these goals. I imagine that this may be a popular model in the future when the concept gets out there. It does require the partners to develop a consensus goal and contractual agreements that take into account all eventualities in the development of the program.  In any case at some point a beginning breeder will become aware of the term linebreeding and choose to investigate what exactly it means. Here we will provide some additional information and even map out a line breeding plan for the beginner.
 
Linebreeding in a short term sense is rather easy and in most cases the novice breeder that gets good lined dogs from a good breeder and matches them, will obtain a reasonable but probably not improved or refined version of the germ line. In most cases where hobby breeders are functioning solo within an established germ line there is a continual decrease in quality in their generations… or at the very least a step sideways. You will see when comparing the quality of the original foundation dogs to the third generation that the quality has declined rather than improved. Under these conditions one must say “what is the point?” Remember this above all.
 
Line breeding is not a rapid method used to improve a germ-line it is better used as a method used to refine and set characteristics of a germ line.  If you are trying to refine someone elses bloodline using linebreeding.. again what is the point? Can you do a better job than they did using the same genetic material? This is especially offset because a good breeder is not usually throwing away to another breeder the best of their stock.
 
If you are hoping to do more than fix a few characteristics that are already present in the line and you want to instead create a dramatic change in that line then you should not be line-breeding.
 
To clarify the point here is one simplistic example of why one WOULD want to linebreed: You have an established germline with few health issues and a quality phenotype, high mental stability but there is very little working drive in most of the individuals,  You want to add working drive to your already superior quality dogs so you seek out those individuals in your line that have more drive and use these to refine, select for, and attempt to set this trait. Take this example a bit further into complication, with the assumption that within the population that represents your germ line there are 100 individuals to choose from and only 3 of these have a significant amount of working drive, but these 3 also have an undesirable trait found within the line (eg. They may have bad tail set. In this case you would use a quality member of the germ-line that is breeding true for good tails (parents and grandparents have the desirable tails) and cross in the high drive member.

Now ALL THINGS PERMITTED AND GOOD LUCK FAIRY ON YOUR SIDE you have a chance to obtain a puppy that has both drive and a good tail set. This new F1 generation with both desirable traits has the traits but still they are heterozygous thus are not “set” into the genetics of an F1 dog (overly simplified… the puppy is only half drive and half good tail). Now you want to set the traits so you do another similar breeding with one of the other high drive dogs and another good tail dog and again look for the puppy with both traits. The third and final step is to breed these two F1 good drive good tail dogs to each other and pick the resultant good drive good tail set progeny. With logical breeding you can further refine the characteristics, prove you are homozygous for both traits and consider it a successful linebreeding adventure. At this point you would continue to try and refine the drive and tail traits within the line without sacrificing other traits. (This again is a simplistic example used to convey a concept. As with most inheritance there are layers of intricacy to the most mundane of examples and many other factors such as dominance of the particular alleles involved, linkage, co-dominance etc. which may or may not come into play PROBABLY THEY WILL LOL).
 
As you might imagine there is an art and a strong science behind linebreeding and there are a great many methods used to accomplish these “patterns” with the ultimate goal of staying close and refining the foundation stock.  It has been said that Linebreeding is similar to weaving a masterpiece tapestry and there are few that have the actual knowledge to be masterful and fewer still that are naturally masterful. There are a few who are lucky. The majority can talk the talk but cannot walk the walk!
 
One of the best of rationales for linebreeding is as follows-
"The more superior a breeder's herd or flock is to the average merit of its breed, the more reason he has to practice linebreeding to his very best animals or to the very best of the recent ancestors."
In order to be successful at line-breeding you must have all the necessary traits and genetic tools within your germ-line, a reasonably low coefficient of inbreeding in your breeding stock, you must have an ideal firmly set in your mind, you must be prepared to ignore breeding fads and recognize that it is a long ranged plan that must be mapped out ahead of time up to 20 yrs in advance. You must also map out the desired traits up to 20 yrs in the past. Only with this chess player mentality and stringency will you ever hope to be more than a hack, lucky, a failure, or can you hope to do more than watch the continued decline of a germ-line as health problems, non-type traits, and mental instability creep into your program. At the point where this decline happens one must look at the obvious and decide to abandon the original plan and move on to another. Without serious knowledge and considerable luck such a failure will mean the demise of a breeding program. A good breeder will just pack it in at a certain point and except failure. Especially with the APBT there are too many breeders that are continually breeding the same medium quality dogs as their previous generations or breeding lower quality dogs than their foundations. These dogs lack one or more of the defining traits of our all around working breed. The breeder must use selection as a rigid tool in the process. Unless this is adhered to, the breeder will never attain his goal and the program will be doomed to failure. You may produce a beautiful APBT that wins every dog show but unless your dog can work, is intelligent, is healthy, has drive, and a wonderful temperament you have a long way to go.

One of the traits missing in many of the popular lines these days is that terrier drive and tenacity that our superdog BREED was once selected ULTIMATELY and predominantly DEFINED BY.
A beginning breeder must realize that in spite of what others are doing or saying there are very few constructive linebreeding programs and very few bloodlines that can be successfully linebred into the future. The beginner must understand all the concepts that must exist within and be maintained within a bloodline. You cannot select for show ability at the sacrifice of the other important traits of our breed. These are in order temperament (disposition, intelligence), soundness (health), fertility (females that exhibit the ability to raise healthy pups, and males that have the ability to reproduce naturally), and conformation.

If a breeder is first and foremost considering color (I only breed red noses, I only breed blues) then my bet is they will see nothing but a decline in quality over the lifetime of their breeding program.

breeders take note: The APBT is an athlete and a sure sign that you have lost athleticism in your line is when your males are no longer able to successfully mount and breed a female. One particular and overly popular germ-line in the APBT is populated with males that require artificial assistance. They jump and hump but only a few times before having to dismount to rest. Get over your uneducated dog show judge induced need for bone and substance and big heads and get back on track with this athletic breed.

Remember the following rules (1) linebreeding (and inbreeding) are only as viable as a breeder’s knowledge of basic genetics and (2) a linebred pedigree is only as valuable as a person’s ability to determine the virtues and faults of the dogs it contains. When we add the final ingredient of rigorous and non-kennel blind selection hopefully we are on the way to producing better APBTs

The ins and outs of establishing a breeding program.

A smart breeding program always starts with selection of the highest quality foundation females. When you are forced by availability to start with a foundation female that is lesser in quality to others of her line you are immediately starting your journey by pushing the cart up hill. If your foundation females represent the best your germ-line has to offer then you are half way to the success you so desire. This cannot be stressed enough. I see too many new breeders starting with dogs that are nowhere near the quality of their siblings being used as foundation stock. In many of these cases these kennels also obtain a stud “to go along with their foundation female” and the stud also turns out to be of lesser quality than his siblings. Instead of looking at this as a problem they continue on and breed poor quality puppies. Now we are doubling up on lack of quality. Why is this? Because when you obtain a dog from a breeder typically they do not give you pick of the litter without a serious agreement in place, thus you end up with one of the "others" in the litter.

This leads us to the second step in establishing a quality breeding program. You do not need a stud in your yard at first. Outsource to the highest quality males available. Most breeders or male owners will offer stud service if the price is right. Taking this route you have to consider whether you are trying to save money or trying to produce better animals.

An addition to this approach is to utilize one of your foundation females to generate foundation studs which are utilized on other foundation females. This is a complicated strategy and beyond the scope of this discussion.

In example: I note one line-breeding kennel in particular that seems dead set on in-house breeding with no semblance of trait selection. Mearly what appears to be a “We haven’t tried this yet hope it nicks" type of selection. They also started with a low caliber female as part of their foundation. With each breeding we note one or two pups per litter with quality similar to that of the parents, which is a sad thing and is a definite signal for the end of a line-breeding program. A quality line-breeding program will at least maintain the quality of the parents in a majority of the progeny. The particular example here is experiencing inbreeding depression and hidden traits such as bad bites and kinked tails and health problems will become more prevalent in future generations.

So how can I be successful at line breeding? Well you must fully understand the principles BEFORE starting.

OK so let us make a very simple line-breeding program with a short term three generation goal. Because we are considering it a short term program by necessity this program must make use of an existing germ-line developed by some other breeder.

The first step in this example program is the identification and obtaining of the two highest quality females available within a particular germ-line.  This is nearly impossible because breeders that are capable of producing the highest caliber animals are also capable of selecting out the best and keeping them (or at the very least coowning them). Thus, the beginning breeder must settle for an alliance with an established breeder, or most likely settle with at the very least the second best female from a litter as their foundation (already at a disadvantage? Maybe.. maybe not~!). Why not obtain males? Many breeders including myself, believe that the females are the strongest part of the line breeding program and the studs are providers of the necessary genes.  As part of this three generation example, these females should both be closely related (neice/aunt, cousin) but not too closely related (half sibs or sibs). Then another layer of complexity is that these two foundations should be lined down from the highest quality foundation ancestors. In example do everything you can to obtain a bitch and her niece both of which descend from the highest quality female the line has ever produced.

OK so both these females mature nicely and they exceed expectations in Conformation and all other criteria then you are set to start a short term linebreeding program such as I will describe (or a long term which is beyond the depths I will discuss here and does not start with line breeding for sure). BUT what if after a year one of the females does not turn out and is of lesser quality than her siblings and most of the individuals in her line? You love her and invested a ton in her BUT Do NOT attempt to begin using inferior stock or your linebreeding program. Because you product will be as described above just decline in quality compared to the rest of the original line. (You should spay her and try again). The next step in this short term line-breeding program is to select a single foundation stud. The stud should be from a more distant branch of the line, but must have all of the traits we would desire to maintain, certain desirable traits we wish to add to our females, and few if any weaknesses where our foundation females do not have weaknesses, and certainly few or hopefully none of those genetic traits we would wish to avoid. THAT IS ASKING A LOT!!!!! You would breed this stud to both of your females and select from each of these litters the highest quality male AND female puppy. Select those puppies that combine the desirable traits of both parents and have fewer of the undesirable traits. Thus you now have 4 superior puppies. These puppies mature as did their parents and exceed your expectations in Conformation and other breed traits.

The final step is the mating of the half brothers and half sisters to set the traits, which are produced by mating the single foundation sire with the two foundation females. The result of the half brother and half sister mating will be the third generation with the resulting offspring being double grandsons and double granddaughters of the superior male and founded off of your superior females which also happen to be bred down from the ultimate germ-line dam.  From this population we will have now produced a handful of dogs that may match or exceed the quality of the ancestors and set a few new and desirable traits. Note however you have reached what is known as a high inbreeding coefficient in your final product animals. We shall see below that the IC is an important measure of how tightly bred our germline is. Thus we have seen a basic and logical 3 generation linebreeding program now however the IC indicates that for our program to continue we must choose to outcross or outreach (distant relatives but still within the lines) to avoid inbreeding depression.

NOTE: One must not try to linebreed to more than one common ancestor except as noted above using a niece for example of your original bitch. The double grandsons and granddaughters will be genetic sons and daughters of the foundation sire.

Close linebreeding is inbreeding even if it is not mother/son, father/daughter etc. Inbreeding is most appropriately defined by the COI (coefficient of inbreeding) which we do not ever want to exceed 35-50% depending on how perfect genetically our bloodline is. Most lines out there I would not want to see above 25% COI