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COI and breeding of working dogs


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#1 blackacre

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Posted 06 September 2008 - 08:17 AM

*Duplicate of post in another thread

I've been gathering some info for inbreeding and COI programs as promised that I'll post as a separate topic soon.


I won't pursue my previous point here at the . . . er . . . suggestion of our esteemed moderator :rolleyes: (we are communicating privately) but I would VERY MUCH like to read Denise's post on THIS topic. I did join the CanGen list at her suggestion (and believe me, it was as struggle to be accepted as a non-geneticist, given their current mix) and spent quite a while reading some very long, usually erudite and largely civilized posts from a wide variety of breeders and scientists in their archives, while trying to stay current on the list. A losing cause I think. In any case, I am particularly interested in the theory or opinion or ? (even that is under discussion!) that inbreeding for conformation characteristics is more harmful than inbreeding for working characteristics ie that by the very nature of the selection process in the latter case, a higher degree of inbreeding can be tolerated in the case of breeding for work. Or, to put it another way, that what would be a dangerous COI in a show breeding program would not be so in a working breeding program. I THINK I've expressed that correctly. This is Wendy's point I believe and perhaps others would agree or disagree. I'm interested to hear.
Can we discuss this? Is it premature, Denise, given that the discussions rage on, on the other list?
Andrea
PS I've copied this to the start of another thread in Politics.
PPS I'm off to work dogs for the day so will check in later.

#2 Denise Wall

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Posted 06 September 2008 - 08:28 AM

Andrea, I'm not quite ready to post on this topic yet. I'm still doing the research as I have time but I will repost something I posted in the TNS thread that is a variation of something I also posted on CANGEN:

"The only valid argument I can think of for more diversity in dogs
selected for function over conformation with the same COI (amount of inbreeding) is that
behavioral traits are more complex than structural traits and therefore have more complex
inheritance patterns. So unless one is just inbreeding without
selection, selecting for behavioral traits will be much more
difficult to "fix" than conformation traits, therefore the
heterogeneity (diversity of genes) will be greater just by nature of the selection
criteria despite the COI. Science will soon prove this one way or the other through DNA analysis of the various populations.

I think the better health issue when inbreeding for function is due to culling which doesn't really seem to work as far as decreasing expression or preventing increasing incidence of new genetic diseases. "
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#3 Rebecca, Irena Farm

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Posted 06 September 2008 - 08:44 AM

I to am very interested in Denise's contribution here and respect her opinion immensely.

It's my opinion, if I read what Andrea has noted correctly, that we aren't talking about equal COI being okay if the intent that brought it about was one thing versus the other. COI is COI period. If the gene pool is on a significant downward trend for whatever reason - overall - in a breed, I believe it's unhealthy. It will bite us in the behind quickly if we paint ourselves into a corner no matter what the reason.

But what I've noticed from studying the work of the masters at working breeding, is that breeding for the right reasons, in an open minded way, will introduce the art of not only inbreeding to fix characteristics in a line, but also outcrossing regularly to avoid extremes.

Also, variety tends to be introduced since the top lines in the breed aren't exclusively in the hands of the well-heeled elite ("If you can't afford to do 15 genetic and clinical tests and show your dog, you shouldn't breed"). Rather, there's also significant contributions from those who only use their dogs, who choose to "breed up" to studs whose useful characteristics are known to be passed on and are widely known through their handler's participation in trials (usually). And we not only welcome, but also encourage such contributions.

Finally, I personally think those who inbreed within their own lines for their own purposes are a separate question from encouraging practices over the breed as a whole which forward a future bottleneck in the breed. I believe if you truly breed for utility and test every generation against that standard objectively (Robin's appeal to use the work as the standard), that you'll see when you are painting yourself into a corner on a local level, in the development of unproductive extremes, long before deleterious effects are seen in health (something like TNS might be an exception if you are really unlucky).

Anyway, I really only state my very amateur opinion here as an incebreaker because I feel this is an important issue to address.
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#4 Janba

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Posted 06 September 2008 - 09:37 AM

COI is COI period.


I agree with this. Selecting for a trait such as working ability instead of conformation will have no effect on the incidence of things like CEA, TNS, black vs red coat or any other dominant/recessive characteristc unless you actively select away from it or for it.

The reason I see that selecting for working ability maintains more genetic diversity than selecting for conformation is that you don't tend to lose genes from the population. An example of this is the coat length in Aussie show dogs. Smooth coats are not acceptable so the gene for the smooth coat has been lost from the gene pool but is still present in the gene pool they were originally bred from - the working BC. The loss of the smooth coat in itself does not seem to be a problem but what genes have been lost that are genetically linked to the smooth coat?
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#5 mjk05

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Posted 06 September 2008 - 10:53 AM

that we aren't talking about equal COI being okay if the intent that brought it about was one thing versus the other. COI is COI period.

I think that is the hypothesis in Andrea's post (and what Denise is referring to). That a dog whose breeding has selected on the basis of working traits with a high COI will have a higher heterogeneity than a dog with the exact same COI whose breeding has selected for physical traits.

If the gene pool is on a significant downward trend for whatever reason - overall - in a breed, I believe it's unhealthy.

those who inbreed within their own lines for their own purposes are a separate question from encouraging practices over the breed as a whole which forward a future bottleneck in the breed.

I think (and please correct me if I'm wrong, which is quite likely) that this is a separate issue- population diversity rather than individual animal COI. And probably more important in the long term or big picture?

(something like TNS might be an exception if you are really unlucky).

Thanks for that :rolleyes: Diplomacy appreciated.

#6 Tea

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Posted 08 September 2008 - 09:02 AM

But at some point, everyone who breeds must outcross. By this I mean outcross to another breed.

Is this Correct?



#7 Janba

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Posted 08 September 2008 - 09:20 AM

But at some point, everyone who breeds must outcross. By this I mean outcross to another breed.

Is this Correct?


Why to another breed?

If the population of a breed is large enough it is quite possible to outcross to a line that has no common dogs in a 10 generation pedigree and a lot further back than that, especially now that the import and export of dogs is more commonplace.

In a breed with a small gene pool or because of a wide spread incidence of inherited problems it may be neccessary to outcross to another breed to ensure the health of that breed. Google the dalmatian backcross project where a pointer was used to introduce the gene for uric acid metabolism as the gene is missing from the entire dalmatian population and most certainly was well before show breeding. The backcross dalmatians aren't recognised by the AKC.
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#8 Tea

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Posted 08 September 2008 - 09:49 AM

Please understand I am speaking as a lay person but one who has been involved in breeding horses and sheep for a long while.

There is a thing called hybrid vigour which, as you know, creates a more viable offspring via an outcross. Something that I have seen many times when outcrossing sheep and outcrossing horses. I am wondering if this would help with health in dogs. By introducing the outcross then breeding back into the breed the characteristics you want would still be there but something new added. Like the 1/8 or 1/4 Irish draft and 7/8 0r 3/4 TB event horses in GB. I had one that also had some pony in it. They stay sound, have good minds and can really jump. A very common practice over there.
Like the dalmation thing, that is very interesting!
Realize I am not a scientist and some of the explanations of these things go kind of over my head. :rolleyes:

But I have seen these things with my own eyes so to speak over many years.

Thanks for all your info.



#9 Janba

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Posted 08 September 2008 - 10:48 AM

Like the 1/8 or 1/4 Irish draft and 7/8 0r 3/4 TB event horses in GB. I had one that also had some pony in it. They stay sound, have good minds and can really jump. A very common practice over there.


Is the crossing of a TB with an Irish draft really hybrid vigor or is it that the two parent breeds aren't as physically suited to a sport like eventing as the crosses? If you think what a TB was developed for it is to be as fast as possible and to win races which involves a certain amount of flight reflex and hot bloodedness. Soundness over many years also isn't really selected for as most racehorses are retired by 5 or 6. Irish drafts were a multipurpose breed for farm work, harness and riding and bred to be more docile and steady temperament and required to work for many years. It is the same with many of the warmbloods you see, if you look at their pedigrees many have a lot of TB in them, at least here in Australia. It is purpose breeding a sports horse.
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#10 Lenajo

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Posted 08 September 2008 - 10:49 AM

In any case, I am particularly interested in the theory or opinion or ? (even that is under discussion!) that inbreeding for conformation characteristics is more harmful than inbreeding for working characteristics ie that by the very nature of the selection process in the latter case, a higher degree of inbreeding can be tolerated in the case of breeding for work. Or, to put it another way, that what would be a dangerous COI in a show breeding program would not be so in a working breeding program. I THINK I've expressed that correctly. This is Wendy's point I believe and perhaps others would agree or disagree. I'm interested to hear.


I had several points actually, and it's taken 12 hours of driving this weekend to think a lot of it out.

#1 yes, I think COI elevation is more dangerous when the overall breeding decisions are bad.

#2 Bad breeding decisions can ruin a breed irrable without inbreeding or COI elevation. I.e. breeding "whim" genetics like brachycephalic and drawf dogs together to encourage that defect to reappear. Any breeding decision based away from a functional healthy canine is concentrated genetics (related OR not) of that defect.

#3 That said, a low COI does not automatically make a good breeding decision. Nor does a high COI make a bad one.

#4 I think a lot of breeders are fooling themselves when they advertise, and yes they do that(particuraily after exposes like BBC's about "inbreeding" being "bad"), about their "outcross" breeding methods when they base that outcross on shorter pedigrees than 10 generations or more.

#5 if you breed purebreds, you are accepting that their is some value in inbreeding. Whether or not that ruins your lines and/or the breed is based on how you accept the responsbility of that and breeding for the most viable Border Collies (defination: working stockdogs) you can produce. in particular that means cull (spay/nueter) those that do not maintain that "standard" AND those that are not proven at all (pet and sport dogs).

After that...it's back to Denise's Dart Board :rolleyes:

#11 Tea

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Posted 08 September 2008 - 11:41 AM

Aha! More thoughts for Tea!
:rolleyes:
I would say that crossing a pure RID and a pure TB is an outcross......then crossing back to TB is not. But again there you have it...the definitions thing!

My best event horses were...... and This was to the OI level....gosh that was 30 years ago! GLUP!

Most were 1/8 or less RID and TB (BTW this was always with the RID on the bottom.) one was an Anglo/Arab.....1/2 TB 1/2 arab. (To me thats an outcross too!)

At least thats what we called an anglo arab.



#12 DeltaBluez Tess

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Posted 08 September 2008 - 01:22 PM

Denise,

What a great write up!!

Thanks for taking the time do do this.

Diane and the *red-dot-dogs*
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#13 Lenajo

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Posted 09 September 2008 - 09:15 AM

When looking for another article I came across this on the Border Collie

link

Some of the interesting quotes the reflect what we've been discussing on the Boards. (edited to say I'm questioning if I can quote this here. If the moderator says "no" please remove and refer to the link)

So on a short term we may be more outcrossing than in the past, but in reality there is still an increased inbreeding.


Over the last 10 year the CI was 7% on average. Is that high or low? I have the feeling that it is on the low side compared to many other breeds. More than 40% would be considered high by almost everybody, although not uncommon in many other breeds. Near 0% in 10 generations would be considered very low, and it is 4-5% on that time-scale. Probably the average CI is a little higher because the known founders were inbred themselves.

A CI of 7% is certainly low considering the small genetic diversity in the current population (effectively the genomes of 8 dogs). More inbreeding would:

accelerate the loss of genetic diversity,
make more dogs with the same appearance and behaviour,
reduce the possibilities to enhance the breed with ISDS dogs only.

Alltogether I think we may conclude that we still have a healthy population despite the low genetic diversity.


According to the graphs involved their have always been some breeders who used high COI inbreeding but in the 1940s that went up considerably. Wonder why? :rolleyes:

#14 Mark Billadeau

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Posted 29 September 2008 - 11:09 AM

I know I'm late to this topic but I'd love to get Denise's overview of Table 3 from:

Genetics. 2008 May; 179(1): 593–601
Population Structure and Inbreeding From Pedigree Analysis of Purebred Dogs
Federico C. F. Calboli,*1 Jeff Sampson,† Neale Fretwell,‡ and David J. Balding*
*Department of Epidemiology and Public Health, Imperial College, London W2 1PG, United Kingdom,
†The Kennel Club, London W1J 8AB, United Kingdom
‡Waltham Centre for Pet Nutrition, Waltham-on-the-Wolds LE14 4RS, United Kingdom

and how it relates to COI.

Mark

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