interesting read on line breeding - Page 1

"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.  "

 

http://www.westwindgsps.com/linebreeding.htm

Edited comment Western Rider

The problem is there are too many recessive genes for them to ever be all eliminated. If you try, you will wind up with an animal so inbred that...

Oh, never mind...go ahead, give it a try. Mate brother to sister, or even father to daughter See how many generations you can go before you get serious genetic faults popping up and the animals can barely reproduce!

Here's something else you likely didn't know. Genes occur in pairs, known as alleles. One allele wiil come from the father, the other from the mother. If both alleles are the same, the animal is homozygous for that gene. If they are different, the animal is heterozygous. That's how recessive genes hide out in the gene pool. Let's say a dog gets one gene for a stock coat  (dominiant genes are always represented by a capital letter) S and one for a long coat, which is recessive, which we'll represent by a small 's'. So, genetically, the dogs is Ss, and has a short coat, but he carries the long-coat (s) gene.

In order for a dog to actually be long-coated, it must have both alleles for the recessive long-coat gene. If he is mated to another carrier, or a long-coated female,he can produce puppies that are ss, and will be long-coated.

Now, the problem with dogs that are homozygous (ss) for both alleles is they can ONLY produce long-coated offspring. You've lost the gene for the stock coat.

And that is what happens if you do too much linebreeding or inbreeding. Most of the genes will become homozygous, and you will have lost a lot of your genetic variability. Also, potentially harmful genes that have been hidden in the gene pool as recessives can now pop to the surface, and produce animals with serious problems. Yes, of course, you will cull these animals, but their parents and siblings will still carry the genes, so they must be culled too if you really want to get rid of those unwanted recessives!

Ever heard of hybrid vigour? That's a term for what happens when you cross two different inbred strains of the same plant or animal. You often get offpsring that are larger, more vigourous, and healtier in every way.

Scientists have known this for hundreds of years: An animal or population with a high degree of genetic variability is healthier than one that is inbred. 

Am I totally against inbreeding? No. Inbreeding/linebreeding is necessary to maintain desirable traits. But iit's got to be done carefully, by someone who really, really KNOWS the lines they are working with!

 

Here's part of an article by someone who worked with the same lines of dogs for over 40 years.  It shows the sort of kowledge needed to linebreed successfully.

Ursa: this line produces the most beautiful black and silver markings; whether light or dark, they can easily be identified as her progeny, for many generations. Altough very intelligent, they can also be somewhat "stubborn" and need a more dominant owner. This line can excel in all forms of obedience-Schutzhund-etc. when trained by a firm NO NONSENSE method.

Faults: straight ore "east-west" fronts; independent, 'testy' attitudes

Virtues: fantastic hips, excellent well balance bone and size; good movement with beautiful saber tails; black recessives.

The Ursa line blends beautifully with the Kari and Sabrina lines. When crossed with the Ria line, excellent temperaments with extra wide heads can be noted but size can be lost, until the next generation. Ursa/Sabrina lines should ALWAYS be bred back to Kari lines!

 

I purchased a puppy that traced back to her lines, though at the time, neither of us was aware of it. The first time she saw a picture of her, she said, 'That looks like the dogs I used to breed back in the '70s!  That's what a good eye she had for dogs!

"Yes, of course, you will cull these animals, but their parents and siblings will still carry the genes, so they must be culled too if you really want to get rid of those unwanted recessives!" ......SS, absolutely NOT true. Doing that is how the Collie breed was decimated in the US by following that very bad protocol, eliminating Collie eye.

I posted a 3 part lecture on linebreeding and inbreeding that discusses why inbreeding and linebreeding are never going to get those claiming to know what a perfect GSD (or other dog breeds) should be where they want to go with their fantasies.  Genetic inheritance and expression is far too complicated to ever breed out many unwanted traits without breeding in an even worse trait as collateral damage.  Even with single gene recessive traits there are some individuals that do no express the trait and some in many cases that do not fit the model which do express the trait.  There are other factors such as environment and epigenetic control that influence genetic expression.

 

3 Part Lecture on breeding and DNA

Relax, Joan, I am definitely NOT suggesting culling everything. (You missed my sarcastic undertone.) I was just making VKGSD aware that getting rid of the dogs with unwanted genes via linebreeding does NOT work. That's my whole point.

I've heard that collies and shelties are often so closely inbred that the COI for many litters is the same as if the parents were siblings. 

 

EXACTLY Bubba! That's the point I was trying to make. Believing you can 'purify' the gene pool via close linebreeding is old, old thinking. It just isn't possible!

A good breeder knows his lines, and what they are capable of producing. He/she also knows that there's no harm in breeding unrelated dogs that have traits that they want. In the past, many breeders bred type to type, rather than relying on linebreeding to fix desired traits.

yeah right, it doesn't work except that it does.

 

linebreeding  a time proven method GIVEN THE PEOPLE ORGANISING THE COMBINATIONS ACTUALLY KNOW WHAT THEY ARE DOING.

it takes decades to know yr own line well enough to do it successfully, please do not try and dismiss as random matings of siblings.

SS, you have no evidence. you have yr own opinion and you have never established yr own line of dog so yr authority on the topic, what yr read in a standard biology text decades ago?.

 

sure any moron can ruin every system, line-breeding or otherwise.

people that have been in it spanning multi-generations of their own family with proven success and their own line to boast.

the others randomly buy dogs that are marketable this month and breed them.

"I've heard that collies and shelties are often so closely inbred that the COI for many litters is the same as if the parents were siblings."== that's exactly the result of Culling entire litters and parents of those litters in an attempt to extinguish a recessive gene. The gene pool was compromised drastically, so much so there were no options But to inbreed for generation after generation. Overzealous culling because of a recessive gene is more damaging to a breed than the recessive gene is.

depends on yr approach some some show collies were bred for narrow skulls becuse it was mentioned in the standard and put forward by the judges, the result is that same collies ended up with such narrow heads there brains and eyes became grotesque deformed causing much suffering to the dogs, they kept breeding them to each other to get the look.

 

i am not talking about such idiotic extremes at the hands of unethical people.

this type of idiocy;

 

"

Sometimes we see a very small deeply set eye and some breeders and judges favour this

type of eye. Have they considered why the eye is deeply set? It is because the eye socket is deformed preventing

the eye from sitting correctly in the socket! If the eye cannot fully move into the socket it can create pressure on

the brain. We should guard against such exaggerations and consider the health of the breed over fashion at all

times. The Breed Standard says, 'eyes never too small'