Thoughts on dog breeding (Part 5)
Line breeding:
Line breeding today has acquired “a bad taste in the mouth.” When line breeding you are doubling up on desired traits and fixing them in the genotype of the animal in question. The good traits are doubled up upon and any recessive or undesirable traits are also expressed. The advantage of this is that should a genetic disease emerge than it is easier to find out as to where the problem originated from in the pedigree. When one applies the “outcross x outcross” method no one knows after a few generations as to where the problem originated from.
One should take into consideration that a lot of breeders are applying line breeding without them actually knowing it. People assume that line breeding is only applicable in the same parent appears in the pedigree in the 2nd or 3rd generation, yet line breeding also takes place much further in the pedigree including the 5th generation. Have a look at the pedigree of your own dog and you will most certainly find a dog that appears twice in his pedigree within the first 6 generations.
Genetically all that line breeding does is increase the chance that two alleles of a gene will be identical and therefore “fixing” the desired traits in the dog’s DNA. When the sire and dam are related and both carry the desired traits, then by breeding them to each other the theory is that the chance of their offspring carrying these genes and expressing these desired traits will be greatly increased. It can be seen as “manipulating a genetic lottery” by increasing the odds in your favour that the desired traits you are looking for will be present in the next generation.
When a line bred dog is bred to another dog that is not related the resulting litter will be an “outcross” as no common ancestor appears on both sides of the pedigree in the first 5 generations.
Line breeding should not be used when both related parents have the same (serious) confirmation fault). This is a feature that can be detrimental to a breeding program when people get “obsessed” with a certain dog in the pedigree. These are usually top show dogs of the past. Just because the super show dog is in the pedigree of a dog does not guarantee that his offspring will also all inherit all of his desirable features. People become blinded by failing to recognize serious conformation faults that their descendant of this super show dog has. When choosing a breeding partner they end up choosing a stud dog also related to the same super show dog that also has the same conformation fault. Such people think that they are fixing the problem by line breeding back to the super show dog but are in fact ensuring that this undesirable conformation fault is firmly imprinted in the DNA of the offspring, making it more difficult to remove in future generations.
The pedigree (actually a book):
There is a big difference with regards to “looking” at a pedigree and actually being able to “read” a pedigree. Anyone can look at a pedigree and make kind remarks such as “very impressive” and “wow” without knowing what they are actually talking about. Reading a pedigree requires a different approach. It allows one to analyze and answer the following questions:
-what is the breeding plan of the breeder? What where they trying to achieve and improve?
-which dogs combined well with bitches?
-how strong is the bitch line? Has the bitch line been able to reproduce itself over and over again in each generation?
-was the breeder breeding for a specific type or was he/she influenced by the latest trends and gossip?
-Have the desired features been passed on from generation to generation or have they become “diluted?”
-Is there consistency in type from generation to generation?
Knowing the dogs in a pedigree allows us to know what their features and attributes were as well as their faults. Always take into consideration that no dog is perfect but that some are quite close to being perfect!
Reading a pedigree is useless unless you can visualize the animal in your mind. It’s genotype is represented to an extent by his health certificates, show results and working tests.
Be able to recognize patterns in a pedigree. What this means are “bloodlines or genes” that match well together continually giving quality offspring. For example sire A produces very nice puppies with daughters of Sire B but not with daughters of Sire C.
During conception genes combine and reassemble creating a totally new genetic package for the individual. Not knowing which genes originate from which family, which dogs were and were not prepotent, which dogs had serious confirmation flaws causes the breeder to make the wrong selection criteria when choosing breeding stock.
The more quality specimens of the breed found in a pedigree is not a guarantee that the puppies born from such a breeding will also be as good. All it does is increase the chance of puppies being born that are better than the breed average.
Mentors:
People will tell new comers to the breed to do their homework. They will be told to talk to different people and ask a lot of questions and read as much about the breed and related issues as possible. The question remains as to how to approach this when asking questions. Can the person answering your questions give you the facts to support their answers? What are their facts based upon? What are the credentials of the person in question? What is their motive? Is their opinion based on facts or are their own emotions and sentimental feelings involved? Does the person recognize and appreciate a good dog when they seen one (have an eye for a dog)?
Would you go to your butcher shop for advice about your grandmother’s heart medication? Probably not! Yet why is it that when it comes to breeding dogs that anyone and everyone is an expert without taking into consideration their own credentials and previous experience?
The essence of statistics and references:
When reading an article always be critical and don’t believe everything you read. Take a good look at the references used (if they are mentioned at all). What type of references where used?
When reading a study related to a health issue in your breed always look at the statistics involved. What exactly are statistics you may ask? Statistics itself is a type of mathematics used to determine as to how accurate the results attained in an experiment or study actually are. It is an indicator to allow the reader to beware as to whether the results are misleading or biased and not accurate. It takes into consideration the error and accuracy percentage. It gives an insight as to whether there is any relationship with regards to the aspects tested.
Yet far too many studies are published without any statistics. Is the researcher trying to hide something? If I were to tell you that giving a dog five garlic tablets a day will result in him having better front angulation then when not given to the dog would still convince some people. Just show a graph and most people are convinced!
Selection criteria:
What you see when examining a dog is it’s outward appearance (phenotype). Examining a dog’s offspring gives you an indication of his/her genotype.
The intensity of selection is fundamental in improving the quality in your kennel. The intensity of selection is higher for stud dogs than it is for bitches. The reason being is that a good stud dog can spread his genes quicker in a population allowing the breed to improve over a certain period of time compared to that of a bitch. As a result greater emphasis and higher requirements are placed upon the stud dog compared to that of the bitch. When selecting a stud dog it’s traits and attributes are always compared to that of the breed average. For example let us say that a stud dog has a very well developed shoulder and upper arm placement, something that is lacking in the breed. If this dog is used at stud his offspring’s front angulation should improve and be better than that of the breed average. Another example is that of the percentage of offspring a stud dog produces that have elbow dysplasia compared to that of the breed average. Should a stud dog that has bred a limited amount of bitches and 5 % of his offspring have ED and the breed average is 20 % than this dog produces better than the average stud dog. Please not these numbers are fictional and not scientifically proven; do not assume that these figures are applicable to your breed. This is only an example.
To enhance the chance that the stud dog in question has the potential of passing on his front angulation, the breeder interested in using him should examine the front angulation of the stud dog’s littermates, parent and grandparents. Should all of these individuals have correct front angulation than there is a certainty factor created that the dog in question will pass this trait on to his offspring. Should the dog himself exhibit the correct front angulation but his family was moderately angulated then the chance of him passing this trait on to his offspring is greatly diminished.
Different bitches will be more suited for certain sires. Remember that there is not a single stud dog that will suit the genetic needs of every bitch.
Breed type:
Type within a breed is based upon personal preferences. At a show a judge might prefer a certain type as opposed to another when making the final decision between two dogs well constructed.
Type is what distinguishes one breed from another. It pertains to the specific characteristics that make a breed unique. For a Labrador this are it’s head, coat and otter tail.
Bibliography:
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