SV to Reinstate Long Coats in 2010 - Page 11

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sueincc

by sueincc on 06 April 2008 - 22:04

George:  You asked why is a long haired GSD considered a fault and Blitzen tried to answer that question.  Of course then the people who have coats had to mock her answer (typical).  Still waiting for someone to tell us why the SV considers LSC and LC a DQ fault.  I'm hoping we can hear from someone with actual knowledge about why they are DQed, not guesses or rumors.  Blitzen asked the question on this thread:

http://www.pedigreedatabase.com/gsd/bulletins_read/183028.html

 


darylehret

by darylehret on 06 April 2008 - 22:04

Speaknow, I believe you are absolutely right.  I cannot see the relevance of Hardy-Weinberg Equilibrium, or the point of diversity (for diversity's sake) for that matter.  HWE simply tracks genotype proportions within a population, and SNPs count percentages of heterozygous alleles in the chromosomes.  There are all types of selection pressures from breeding, with a wide variety of intents, and different strains from isolated geographical regions, differing purposes of intent (i.e. show/work).  It would probably be foolish to suppose a stabilized balance was ever achieveable in the breed.  The only thing consistant is our continuing disapproval.

Can HWE can even track genotypes where more than two alleles are possible at a given loci, incomplete dominance, modifier genes, or complex/multifactoral traits(polygenic & environmentally influenced phenotypes)?  Probably not, if the phenotype isn't easily appearant.  Heck, we can't even agree on what a bicolor is, or tell the difference between a black&tan and a sable at times!

I think there's plenty of diversity, in fact too much "disorderly" diversity in the breed.  Sure, you get alot of latitude of what you can breed with to maintain "purebreed" status, but genes don't read pedigrees, and "type" becomes lost when there are no intents of maintaining it with mismatched breedings.  A puppy doesn't grow to achieve in sport the combined average of it's parent's schutzhund scores.  But you'll find breeders who seem to think so.  Same with ZW ratings.  These are meant to be tools, where the translation somehow gets lost.

Everyone repeats the mantra about linebreeding being "bad" and outcrossing "good".  It improves "diversity"....  which can be fine and useful if it's orderly maintained, quite a mess if it isn't.  I firmly believe consistency is the product of well structured linebreeding, and that occasional outcrossing is useful and necessary.  I also would say that in a given litter you could actually be linebreeding and in another sense, outcrossing simultaneously!  Puppies aren't the "crapshoot"... breeders are.

Sort of like Do-right says, I'm inclined to make the best decisions I can, with the most practical and useful knowledge at my disposal, breeding the best dogs available to me.  If you find what you want in a longcoat, why not?  Not my personal preference, but more important things should be the focus.  How have longcoats persisted since the disqualification?  Are today's examples the result of papered gsd breeding that didn't pan out, or did they continue after the break with their own registry?


by Blitzen on 06 April 2008 - 23:04

Uh, Max Bear, please quote from one herding breeding standard that says the dog should not have undercoat and harsh guardhairs regardless of the length. Thanks.


by Blitzen on 06 April 2008 - 23:04

Make that dogs that herd where the temp drops below 32 degree fahrenheit. African dogs don't count.


by Blitzen on 06 April 2008 - 23:04

George, you didn't do or say anything wrong.


by Speaknow on 07 April 2008 - 08:04

Here’s some basic genetic stuff cannibalized from the Net, Daryl – hopefully some will find it interesting: Inbreeding is the breeding of two animals who are related to each other; in its opposite, outcrossing, the parents are totally unrelated. Since all pure breeds of animal trace back to a relatively limited number of foundation dogs, all pure breeding is by definition inbreeding. It is easier to lose genes (often very desirable ones) from the breeding pool when inbreeding is practiced than for a more open breeding system. Or, inbreeding will tend to produce more nearly homozygous animals, but some of the homozygous pairs will be "good" and others will be "bad". Naturally, we look for homozygosity for those genes creating desired similarity to the breed standard; however, inbreeding tends to remove those heterozygotes that are beneficial, and those undesirable, as well as desirable homozygotes. The practice leads to a potential increase of homozygous health problems not directly evident, but which nonetheless shorten the life span or decrease the quality of life for the animal. Wright’s inbreeding coefficient relates to probability that both copies of any given gene are derived from the same ancestor. A cold outcross (in dogs, probably a first-generation cross between two unrelated breeds’ purebreds) would have an inbreeding coefficient of 0; though this doesn’t mean progeny would be heterozygous at every locus. Also, the chances are that our dogs with inbreeding coefficient = 0 would still be homozygous for those genes shared by all dogs. The inbreeding coefficient thus specifically refers to those genes that are variable in the species and even the breed being considered. An inbreeding coefficient of 1 would result if the only mating practiced over successive generations were between brother and sister. As a general rule, very close inbreeding, say for mentioned brother-sister matings, cannot be kept up beyond 8-10 generations, as by that time the rate of breeding success is very low. Yet, two very inbred parents can produce offspring that have very low inbreeding coefficients if they do not have common ancestors.

by Speaknow on 07 April 2008 - 08:04

Following snippet is carved from a very good piece by Fred Lanting I hadn’t seen previous: Line-breeding and inbreeding is one of those areas where he dog world seems unwilling to learn from science. There’s no real difference between the two terms: line-breeding simply describes the inbreeding on animals a little further back in the pedigree than otherwise. Inbreeding eventually results in “inbreeding depression”, with less resistance to stress and disease, fewer offspring, and shorter lives. Research evidence suggests artificial selection is deleterious and that natural selection produces greater diversity and thus a higher health safety level. Even in Germany, where breeders formerly prided themselves on keeping “open” at least important sire lines that went back to dogs not found as often in modern pedigrees, it has become almost impossible to find GSD “show” dogs that are not line-bred on Palme WildsteigerLand and the Q-litter Arminius. As a result of moderately strong line-breeding, we find problems such as the immune system deficiencies in Lasso Neuenberg and others’ offspring, nagging high levels of HD in Zamb Wienerau descendants, low percentages of Körklasse-1 in Tacko Wienerau and even Sieger Lasso offspring. These merely represent many similarly problematic dogs, and such weaknesses are the natural result of breeding to the same small number of dogs or bloodlines. In other words, the loss of diversity of genes is directly responsible for much of the genetic problems seen today. Dwarfism and hemophilias in the German Shepherd Dog, and many other examples of genetic disease are linked to a decrease in outcrossing. And if the Germans don’t start tightening up on GSD hip and elbow joint quality, and loosening up on the narrow focus of the bloodlines used (working lines are almost as bad in this respect as show lines), they will soon paint themselves into a corner the way the Americans have. Inbreeding depression walks hand-in-hand with loss of heterozygosity and the lower utilitarian beauty of the modern German Shepherd Dog. The most common route to inbreeding is the widespread use of a handful of top VA animals to the exclusion of other good but less-highly placed competition dogs. You may be increasing the chances of getting a dog that has some of the same obvious (probably dominant or homozygous) desirable qualities, but are also concentrating the so far hidden recessives, many or most of which are bad for the breed. When most people flock to the leaders for stud service, these bad genes are concentrated as well, and the good genes that an unused dog could have contributed may be lost forever. The previously hidden undesirable recessives will soon become glaring problems, impossible to ignore and difficult to get rid of. Whenever possible, outcross! And encourage the national breed club to use genetic diversity in recognizing the value of the dogs and lines.

pod

by pod on 07 April 2008 - 09:04

"Can HWE can even track genotypes where more than two alleles are possible at a given loci, incomplete dominance, modifier genes, or complex/multifactoral traits(polygenic & environmentally influenced phenotypes)?  Probably not, if the phenotype isn't easily appearant.  Heck, we can't even agree on what a bicolor is, or tell the difference between a black&tan and a sable at times!"

The purpose of Hardy Weinberg principle isn't to measure number of alleles or diversity of a locus. It is simply to determine expected frequencies of two alleles at a given locus.

The results from the paper should show that it isn't either a method of measuring population (breed) diversity, and this is made clear in the report  section - HWE by subbreed

Analyzing the poodle by its respective subbreeds (toy, miniature,and standard) showed a vast improvement in the percentageof SNPs in HWE (Figure 2). The poodle group as a collective had 61.4% of the SNPs in HWE, whereas the individual groups had 99.2% in HWE for the standard poodle (n 5 5), 97.5% in HWE for the miniature poodle (n 5 5), and 92.4% in HWE for the toy poodle (n 5 5). This trend was seen for all the breeds that were analyzed as collective groups and then by subbreed.        

  http://jhered.oxfordjournals.org/cgi/reprint/98/5/445

There's no way that a single breed could have a higher genetic diversity than a collective group including that breed.  What this is showing that there is different selectional criteria amongst the Poodle breeds, and no doubt the reason the GSD shows high disequilibrium is because the high number of sample dogs spanned differing types from populations that also have different selectional criteria eg the work/show divide.

I do agree that allowing longcoats into the showring isn't going to affect breed diversity, well at least it's not going to increase it.  Nothing can effectively do that except the introduction of new blood fom another breed, but it may slow down the loss of diversity by making more dogs available for breeding.  But, and this is a very big but... it could make lines available from other factions of the breed eg show people may want to use dogs from established longcoat lines and vice versa.  This won't of course increase breed diversity but it will open up the individual ines.

 


Videx

by Videx on 07 April 2008 - 10:04

Perhaps the Long coat GSD should be recognised as a separate breed. Other breeds are split into several groups, which are then governed by rules & regulations regarding breeding,exhibiting etc. such as the Dachshund, why not the GSD??


by Speaknow on 07 April 2008 - 10:04

As I understood it, pod, the HWE seeks to establish the reliability of using canine genetic information, as impacted upon by disease etc, as a valid basis for extrapolation to humans. I also couldn’t see how it related to genetic diversity, as opposed to Wright’s Inbreeding Co-efficient say. And as I see it, the only means (other than for more drastic step of ‘hybridizing’ with another breed) whereby show-lines may avoid near-term genetic dead-end is by outcrossing to working-lines blood – particularly since the Wienerau dog singularly concentrated and re-directed away from what came before, and in that the two lines have been genetically mostly separate now for many a decade. But is it, Videx?





 


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