In-Breeding %

% Inbreeding

Really there is no ideal percentage. Most of the Shetland sheepdogs in this country are quite highly inbred-they trace back to a fairly small number of ancestors. Inbreeding is not in and of itself harmful. Inbred dogs inherit the good and the bad from both of their parents. Inbreeding does not cause mutation. It does however tend to bring whatever strengths and weakness that are in the line to the surface. Ideally breeders seek to emphasize the strengths of their lines and eliminate the weaknesses. Inbreeding and line breeding are merely tools.
 
Emma is at 4.92%. I know some her breeder's litters are higher up to at least 11% or some. I can't remember the exact number. I know the breeder doesn't like to go too high.
 
I never thought much about this before...can someone explain line breeding to me? I'm not sure I understand.

And, interestingly enough, Bentley is 16% and Lexi is only 4%. Bentley's sire is 28%--very high.
 
I think it's true that there isn't a hard-and-fast cutoff number... but getting into the 20-30% mark does make me nervous. At the same time, a half-brother/half-sister mating can cement type and yield a perfectly healthy dog. However, when you move forward in your breeding program with that dog, you need to use him/her carefully (and you need to have known, before the original breeding was done, that you were working within a very healthy family).

Inbreeding/linebreeding are just a part of the breeder's toolbox. Like any tools, you can use them judiciously and well, or you can use them very badly indeed.
 
Out of random curiosity is there anyway I would be able to tell Smudge's percent without being told?

You know, just for cringe factor. :lol:
 
corbinam said:
I never thought much about this before...can someone explain line breeding to me? I'm not sure I understand.
Click to expand...

Linebreeding is breeding less-closely-related dogs to each other (breeding "within a family"). You can also "linebreed on" a specific dog.

Here's a pedigree for one of our own dogs:
http://www.pedigreelines.com/dog/pedigree/id/30558

"Robbie" (Maritime) can be described as being "linebred on" Trade Mark, and on Laureate Savanna White (the Trade Mark x Savanna White breeding was repeated multiple times, with excellent results). His % of inbreeding is a little high (21%), but he represents the mixing of common ancestors to produce a typey dog who shows a family look. Going forward with him, we would use him (and his litter-sister) carefully to reduce COI while maintaining breed and family type.

Here's the pedigree of a Robbie niece:
(ok, the trial cross isn't showing up! but you can see it if you do a test breeding between Shelhaven Promiscuous and Ventura Expectation.)
(note: "Tansy" [Rabbit Run Fun and Games] is NOT out of Shelhaven Promiscuous; she's out of her litter sister, Rabbit Run Game Face, who isn't on Pedigree Lines. The pedigrees are, of course, the same.)

Here we have another pedigree further linebred on Trade Mark, but with more family variety. This pedigree incorporates our other Mark daughter, Shelhaven Rabbit Run Rhapsody, as well as an outcross from Willow Cove Wild Card, through the side. The COI is reduced, and the resulting puppy, Tansy, is exactly what we, as breeders, were looking for.

Linebreeding is like mild, multivariate inbreeding. Instead of having one closely-related cross, you're working across generations of not-so-closely related animals. It's a little tricky, but very powerful.
 
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There was a total of 44 different dogs in his 5 generation pedigree if I counted right. 17 dogs were used twice. I'm too lazy to do the math, but I'm guessing that's not good. :sadsmile:
 
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