How close is too close (linebreeding) - Page 1

Hello -

I am considering a dog who is the result of a 4-5 linebreed on a really awesome and well-known champion, at least according to the five generation pedigree presented by the AKC paperwork and also on this site. However . . . when reviewing the pedigree a little further back, it reveals that this dog is the result of a mating between a male who was bred 3-5 on this really awesome champion and a female who was bred 4-5 on the same really awesome champion. Thus, according to the 5-generation calculation available on this website and also verified on the AKC 5-generation pedigree, there is only a 4-5 linebreed within 5 generations. But going further back, there's more. How can I calculate the correct inbreeding coefficient according to Wright's or Hardiman's methods in this case . . . and what percentage is considered too high according to either method? Is it considered to be okay to breed two dogs together who have both already each been linebred on the same champion dog within five generations, or not? I've noticed on the site that some dogs presented seem to have been the result of this sort of thing.

Thanks in advance to all of the knowledgeable breeders and enthusiasts out there who are willing to weigh in on this question and educate me. :)

There must be some doubt in your mind or you wouldn't be asking this question. I think you know the answer to your question...mine would be when in doubt don't do it.

There must be some doubt in your mind or you wouldn't be asking this question. I think you know the answer to your question...mine would be when in doubt don't do it.

There must be some doubt in your mind or you wouldn't be asking this question. I think you know the answer to your question...mine would be when in doubt don't do it.

This website has an option to look at line breeding up to seven generations. There should also be inbreeding coefficients presented.

What you're describing sounds like 4,6-5,6.

A 4-5 or 3- 5 is not that close but the main thing is there is not repeated patterns of health -body , or mind issuses of the dogs that are being linebred on. Some linebreedings are better to stay away from.

The lower the better that's what i can say like that of Sieger Vegas.

If i may quote: "So, in terms of health, a COI less than 5% is definitely best. Above that, there are detrimental effects and risks, and the breeder needs to weigh these against whatever benefit is expected to gained. Inbreeding levels of 5-10% will have modest detrimental effects on the offspring. Inbreeding levels above 10% will have significant effects not just on the quality of the offspring, but there will also be detrimental effects on the breed.
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For comparison, mating of first cousins produces a COI of 6.25%; in many societies this is considered incest and is forbidden by law). Mating of half-siblings produces a COI of 12.5%; mating of full siblings produces a COI of 25%

Even 100 years ago, the costs and benefits of inbreeding were recognized, and even if the mechanisms weren't fully understood, breeders knew from experience that there were tradeoffs. The Coefficient of Inbreeding was formulated specifically to serve as a tool to quantify these risks and benefits in a way that could be used in making breeding decisions. (See Wright's Coefficient of Inbreeding)

It's easy to make the lists:

ADVANTAGES

increased uniformity
increased prepotency (ability to pass on traits to offspring)
“fixing” of desired traits and breed type

DISADVANTAGES

lower fertility
lower “vigor”
birth defects
smaller size
fewer offspring
slower growth
higher offspring mortality
shorter lifespan
increase in genetic diseases
reduced “genetic potential” (ability to improve a trait)


Resources: Carol Beuchat PhD - The Institute of Canine Biology

Too close is 2-2 on the puppy... A 3-2 is close... Opt for a 3-3 inbreeding rather; and if you intend to breed him or her at a later stage, you can even outcross to a good line - just to avoid inbreeding depression. In your current case, I wouldn't have worries, but it's always best to know the dogs.

I will not dare to touch a puppy with this linebreeding:
3 – 3
4,5 – 5
5 - 5,5
5,5 - 5,5
5,5,5,5 - 5,5