We breed with both phenotype (appearance) and genotype (genetics) in mind. The ‘papers’ that come with the dog are not necessary the most important thing. Too many people make the mistake of breeding ‘paper tigers’ – mastiffs with famous ancestors in their pedigrees. If you are hoping for pups that look like the pups that are his progeny than you need to have that same bitch, a sire will only reflect the bitch that is given him. As well, championship aside, how healthy is this dog? Championship dogs are not necessarily health tested – a 2 year old champion can soon be a 4 year old crippled mastiff with severe and debilitating hip dysphasia, or genetic heart problems and so on.

A good breeding program needs a sound foundation, both in the breeding dogs being used and background information on those dogs. Assessment of genotype is done by genetic screening and evaluation of ancestors/ siblings/ progeny. This is crucial to make accurate assessments. People often wonder why our contracts require they stay in contact with us for the lifetime of their mastiff, well if we don't test or follow-up on all offspring and siblings, how will we know if we do or don't have any problems.

Breeding to a top show dog or champion will not necessarily guarantee good quality pups. Selection of individuals with similar phenotype -- not having faults in common -- is absolutely necessary. But still quality is not guaranteed, as the two may not be a match for producing their good traits. So in our opinion a personal study of as many dogs in the background as possible is best and this is what we undertake when we look for a potential dog .

None of this is meant to say that a champion show Mastiff is not an excellent choice , it is just meant to put into perspective that the mastiffs ‘paperwork’ is not everything. A buyer should consider every aspect of the dog before purchasing.

So, considering both appearance and genetics we strive to breed genetically healthy, beautiful mastiffs with gentle temperaments.  Our mastiffs litters are healthy and this is the most important thing we can do as a breeder. To produce untested and unhealthy mastiffs is irresponsible and unethical. There are many ‘backyard’ breeders out there who do not health test, nor will they be there to support you if there are problems with your pup. If you want to have a mastiff puppy the most loving thing you can do is ensure it will remain a healthy and strong dog for its entire life. Nothing is sadder than a 2 year old mastiff with hip dysplasia and a lifetime of pain and suffering ahead of it.

One should also give some serious thought to the term ‘perfect’ and ‘guaranteed’. Our expectations from breeders are very high. We expect a pup to be perfect in every way and to stay that way throughout its life. That is not possible –nor is guaranteeing that. There is no such thing as perfection, in humans or in animals. That said we do strive for the best we can produce and do guarantee against serious genetic health problems. So we would just caution people to be realistic with their expectations because we are, if we were not we could not do what we do, nor could we have and love the wonderful mastiffs that we own.

Finally and just as importantly there is the subject of temperament. we firmly believe that temperament is 25% nature and 75% nurture . We always look at the history of temperament in the ancestors/siblings and this will tell you something if it is not right – this is almost always a problem with severe in-breeding. Mastiffs in general have fabulous temperaments, and any dog can have a terrible temperament if allowed too, that is where nurture comes in and the importance of socializing and training mastiffs but that is another subject.

We do not breed a bitch until 18-24 months with 24 months being the goal, meaning that if a bitch goes into heat at 18 months her heat cycle lasts one month, her pregnancy two months putting her at 21 months, at which point we consider her mature enough to whelp. We will NOT breed a female younger than 18 months.

Most common types of Breeding used today:

In-breeding
Inbreeding is the mating of very close relatives, for example, father to daughter, half-brother to half-sister, brother to sister, mother to son, etc.

Inbreeding intensifies the faults as well as the strong points, so considerable discretion must be used in the choice of the dogs. The faults may be to such an extent, that, sometimes, entire litters have to be destroyed in cases where obvious anomalies occur. For this reason, this type of breeding is not recommended to novice breeders.
Sometimes, in-breeding is the only option available, for example, in the re-creation of a nearly extinct breed or in breeding programs of newly created breeds

Line-breeding
Line breeding is the mating of dogs having many common ancestors or mating to a slightly removed relative, e.g. granddaughter to grandsire, uncle to niece, etc.
The benefit of line-breeding is the production of more consistent litters.
In order to have a chance to reinforce desired characteristics and eliminate health problems one has to have a thorough knowledge of both pedigrees of both the sire and the dam for at least five generations.
In general, most breeders adhere to a policy of line breeding, whereby they can assure uniformity of quality without risking the inherent dangers of inbreeding.
This technique appears to be the best compromise between inbreeding and the doubts of Outcrossing or Outbreeding.

Out-crossing
Outcrossing is the mating of two dogs that are the products of line breeding but of two distinctly separate lines. This means that the breeder is breeding one or more of their dogs with a different BLOODLINE outside of what their current stock’s bloodline is. This does NOT mean that they are breeding an English Mastiff with a different breed, such as a Rottweiler.
Unless the two dogs involved in an outcross are strongly linebred with a possibility of a certain measure of prepotency, uniformity to the first generation is generally doubtful.
It is generally employed as a long-term proposition to bring certain traits into a line that is otherwise deficient. These traits then need to be intensified by proper line breeding or inbreeding.

Out-breeding
Outbreeding is the mating of two dogs who not only are the products of two distinctly separate lines, but on top are not the products of line breeding.
Outbreeding is seldom employed since in most breeding programs dogs that would qualify for Outbreeding simply do not exist.

In summary, most successful breeders use some formula involving general line breeding with inbreeding employed when sufficiently outstanding products of their line result and outcrossing only when another line can supply a strong characteristic in which they are lacking.

Some animal breeders, including many dog breeders, make a distinction between inbreeding (mating mother/son, father/daughter, brother/sister) and line breeding (mating say grandparent/grandchild, aunt/nephew).

To a geneticist line breeding and inbreeding only differ in degree. Inbreeding occurs when animals are bred to their relatives. The closer the relationship the higher the "inbreeding coefficient". Inbreeding coefficients measure the degree of inbreeding an animal shows relative to a randomly breeding population.

Inbreeding reduces fertility, vigour or overall health and mental stability. Inbred animals are more prone to diseases such as infections and cancer, and more likely to be "highly strung".

To understand why this happens we need to consider basic genetics:

All animals, including people and dogs, carry two copies of each gene - one from our mother and one from our father. These genes are unique sequences of DNA, each of which codes for a unique protein. Changes in the DNA code (called mutations) change the structure of the protein produced by the gene and as a result change the way the protein works.
Because evolution has for millions of years selected for perfection of performance most changes or mutations are less effective than the original gene copy. The chance of having an abnormal copy, or mutation, of any one particular gene is low, but because we have so many genes we all carry some harmful genes. These genes are usually hidden because we have one good copy of the gene to carry us through and this gene produces a normal protein which can perform the tasks required. When we have two different copies of a gene we are said to be HETEROZYGOUS for that gene and if one gene copy is hidden by the other, the hidden copy is said to be RECESSIVE.
If both copies of a gene are the same then we are HOMOZYGOUS and if the copy is "bad" then that gene won't work normally and we will be to some degree less healthy. Some single genes are so important that affected animals die, or suffer debilitating disease and some have only minor effects - affecting for example jaw structure or coat color, the efficiency of an antibody molecule, the structure of a neurotransmitter or the shape of a red blood cell.

As animals are mated to their relatives, however distant, simple mathematics will show that the likelihood of any one gene becoming homozygous will increase. As homozygosity increases, variation among offspring decreases. The dog breeder takes advantage of this in line breeding to produce a breed which "breeds true" and conforms to a "breed standard" and within the breed to produce offspring that are like peas in a pod. Breeders look for a "proponent" sire or bitch ( i.e. one that always throws pups very similar to itself). These animals come from a "good linebred pedigree" - that is one that is inbred so that the animal is homozygous for as many as possible of the characteristics that the breeder regards as desirable.

Unfortunately this search for perfection and uniformity comes at a cost. Undesirable genes also become increasingly likely to be homozygous and so affect the health of the animal. Most of these genes have minor effects which gradually accumulate. There are many genes involved in traits like fertility, immune competence and mental stability and accumulation of homozygous recessive "bad" genes gradually diminishes the function of these systems.


ON RECOGNIZING AND ACKNOWLEDGING GENETIC TRAITS – RESPONSIBLE BREEDING

Genetic disease is not some sort of shame to be hidden and whispered about & it shouldn't be overlooked or forgotten. Genetic disease should be documented so the breeding of two carriers of something really scary can be avoided. One of the HUGE reasons purebreds have so many problems with genetic disease is this culture of "hide it, deny it, lie about it-while others whisper and gossip." Come on people--if we are not ashamed of what we are breeding, and if we are really concerned about the state of our 'beloved' breeds, then why are we not honestly documented the faults found out in our lines? (What we need is open registries, but this is another topic, sort of.) The result can be that honest breeders who admits to line faults may get bashed by their peers as well as puppy buyers, while those who hide their problems successfully often get rewarded with breeding and buyers. Let's all get a little more sophisticated, shall we? Treat each dog like he HAS three undesirable traits & try to prioritize what is and is not acceptable; what is and is not also in your/another line. Puppy buyers, ask what the line has & expect an answer that it does have some less than wonderful things-focus on what the breeder is doing to eliminate or control them & try to find someone with a list similar to yours (of traits bad, maybe, but at least livable/acceptable).

Puppy buyers can help out by not running away from an honest quality breeder who tells you his/her line carries for this and that & running to the ostrich-sort of breeder who lives with head deeply buried in the sand. They can also help enormously by ceasing to support those who breed casually and in ignorance. It's a lack of knowledge of how to properly set up a successful breeding program more than any evil designs or other nefarious motives than is destroying purebred dogs. Sadly this decline is largely funded by pet puppy buyers who often don't seem to think the quality of the breeding program is important when buying "just" a pet. It's the buyers that keep the sellers in business & it's often overlooked that current buying practices are largely responsible for the decline in the overall quality of pets for sale.

Myths about Genetics - If it is a genetic trait & you have the gene, you are going to get the disease, etc. associated with the trait. This is probably one of the most commonly held & terribly wrong notions people have about genetics. Innate does not mean fated. Having a gene for some trait may be a LONG way from having the trait expressed; you won't get sick necessarily just because you have a gene for a disease. Genes don't "cause" disease; the expression of them may. Of course "carriers" are best identified & eliminated when possible from the breeding stock, but such ideal circumstances may not be available & it's critical to recognize that genetic traits are not like a scarlet letter that brands someone as a "defect," just as it's critical to recognize that we all (& all our dogs) carry defective and even lethal genes. The key, again, is selection: selection as a breeder for what defects are tolerable (i.e. those cosmetic or fashion) and which are not (i.e. those deadly or costly).

Myth - You can buy/breed a dog without undesirable genes. This puppy buyers often demand and some breeders even will promise. Every dog alive likely carries some undesirable traits. In the breeds where this has been systematically studied, every breed individual is likely to carry for 3-5 unwanted traits (gene load). The question is less rather IF you will accept unwanted traits, than WHICH you will decree as most undesirable & which you (and your dog!) can accept and live with. Crooked tails or missing teeth sure beat heart disease and hip dysplasia---all are inherited. Which, if you had a choice, would you choose to carry in your line or have in your dog? This is rather hard for folks to swallow as they believe & think your genes are you destiny and that anything genetic is some sort of scarlet letter. We all need to learn a bit more of how biology really works & discard our erroneous ideas not based on the evidence of nature
 

A very simplified description is as follows.

The first is called line-breeding, and is generally accepted to be the correct way to breed dogs, cats, and all types of livestock. With line-breeding, you breed dogs that are related, but not too closely. i.e. cousins
The theory with line-breeding, is that you will start to produce dogs with a predictable appearance to them. This way you can identify any problems that are appearing in the dogs you produce, (or lines), and can then try to correct those problems by out-crossing. Out-crossing is usually done after 2 - 3 generations of line-breeding. For example, I might be producing Mastiffs with great heads, but not very strong rear ends. I would then look for another line-bred line, (not related to my dogs), that produces very strong rear ends. Then, I would start line-breeding again, while retaining a strong rear end.

So, out-crossing is the second kind of breeding, and it is breeding completely unrelated dogs together. The problem with out-crossing, is that you lose any predictability in the pups. For example, as in the above, let's say I out-cross to a line-bred line to try and get good rear ends. I may not get those strong rear ends in the puppies at all! And could even pick up something I don't like from the line I just bred to - like eye problems. Out-crossing is an educated guess.

And the final type of breeding, is in-breeding. This is breeding closely related dogs together. Many breeders feel this type of breeding is perfectly fine. And breeders quite often disagree as to what, exactly constitutes in-breeding.

In my opinion, fathers/daughters; mothers/sons; brothers/sisters; and half-brothers/sisters are all in-breeding. In Mastiffs, there is a tendency to lose size when in-breeding. In all breeds, you can get some fantastic puppies when in-breeding, but you can also get some unfortunate results when in-breeding. Guess who gets those? Be very careful if you're being offered a deal for a puppy. As well, only very experienced breeders who have a thorough knowledge of their lines should attempt in-breeding. And it should only be done once - not repeatedly! What a recipe for disaster!

Successive in-breeding can result in poor immune systems; and all kinds of genetic defects. Why do you think it's illegal for humans to marry closely?

This has become the reason for all those weird breed crosses that have become so popular - supposed hybrid vigor in things like schnoodles; pugles; golden doodles, etc. This is not the case, but you do have to be aware of your pups pedigree, and avoid problems. Educate yourself!

 

Source and Guidance by : Heidi Kulcheski ( www.mountain-stream-mastiffs.com ) .Heidi has been a great fountain of information about breeding Mastiffs and raises her dogs with affection and in a humane and ethical manner.