Humble GS is an excellent example of sex-balanced line breeding.
I never said the population was “non-viable”. I said it’s in danger. And it is! If most all of the animals are near clones of each other, then so are their immune systems. Should some disease come around that none of them can survive from, then they could be toast. Also, as I said, they’re fertility stinks and their life spans are short. Both signs of inbreeding depression.
[QUOTE=D_BaldStockings;7212573]Point 2.
Horses have been domesticated for approximately 7,000 years - dating to 5,000 BC. And possibly domestication took place at one location.
http://archaeology.about.com/od/domestications/qt/horses.htm
You can look at this from two viewpoints:
Extinction of horses is inevitable as the gene pool is already too limited.
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Are you being serious? The fact that horses are domesticated doesn’t mean that they’re gene pool is too limited for survival. We already know through DNA anaysis that horses are extremely varied in genotype. Also, some horses have been selectively bred using only a handful of “founders”, and turned into exclusive “breeds”. Just like with most dog breeds. (And this really didn’t go into full swing until after Darwin and Galton’s theories became popular.) And YES, some of those breeds ARE extremely vulnerable!
[QUOTE=D_BaldStockings;7212573]If cheetahs can thrive with natural selection for 10,000 years in one location, one environment despite the presence of 2 larger predators they cannot overcome (lions and leopards) and, while, rarer than these predators, were not dangerously threatened until human degradation of habitat and systematic hunting…
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How do you know that Cheetahs have “thrived”? I believe that one article I posted stated that they used to be found worldwide 10,000 years ago. Now they’re only in part of one continent. I wouldn’t call that “thriving”.
[QUOTE=D_BaldStockings;7212573]Then horses, which are distributed world wide and encompassing many distinct phenotypes and breeding groups will probably not be damaged by careful inbreeding and linebreeding during the relatively short human lifetime a breeder works with their stock before passing them on to breeders of the next generations, always assuming sound, healthy stock are slected each generation.
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Inbreeding depression can happen rather quickly (in just a few generations). I believe the Spanish Habsburgs managed to kill themselves off in something like only 5 or 6 generations. And they weren’t inbreeding as much as some horses and dogs are. http://blogs.discovermagazine.com/gnxp/2009/04/inbreeding-the-downfall-of-the-spanish-hapsburgs/#.Ul18BySmVlI Granted, they weren’t “culling” the unhealthy ones, but the problems did begin to diversify and magnify with successive generations. Also, some of the Muslim populations are showing signs of inbreeding depression now due to common marrying of first cousins. http://www.dailymail.co.uk/news/article-1392217/Muslim-outrage-professor-Steve-Jones-warns-inbreeding-risks.html
[QUOTE=D_BaldStockings;7212573]Point 3.
Some breeders of horses created some pretty good breeds and families within breeds by linebreeding and inbreeding; the Morgan in the USA for one example, the Suffolk Punch draft in England for another; both breeds noted for longevity, fertility toughness and utility.
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I do believe I have already said that I don’t entirely disagree and that my beef is more with linebreeding in the confines of a closed studbook. Such as in most dogs, and Friesians for example. These breeds are already genetically starved. Purposefully linebreeding and narrowing them even more is ridiculous, IMHO.
[QUOTE=D_BaldStockings;7212573]Point 4.
Hybrid corn, for instance is the result of crossing 2 semi-unrelated inbred strains.
Many have thought that regression would occur if the first cross were mated to each other, however, studies at some universities have not shown significant loss of vigor or production to the 7th genration descendants (none of which, to the 15th generation were as weak as the original inbred lines used to create the first cross).[/QUOTE]
And those results don’t surprise me. But the fact is that they DID eventually regress, which would be inevitable. Especially if they were culling out lines with each generation.
[QUOTE=Tradewind;7214290]
An interesting example of consistent linebreeding in a breeding program is that done by Galten Farms. Their superstar mare, Abiza (dam of Abdullah, Pan Am medalist Amiego, approved stallion, Adrian, among others) is the foundation of their breeding program and most of their broodmares are linebred (some heavily) to this mare. They have also bred some approved stallions that have considerable linebreeding to several marelines, in particular. This breeding program has produced a slew of international jumpers and event horses. Here is the pedigree of their young homebred stallion, Humble GS, who has recently made his eventing debut with Jessica Phoenix:
http://www.allbreedpedigree.com/humble+gs
and a homebred stallion they previously stood, Arapaho:
http://www.allbreedpedigree.com/arapaho+gs[/QUOTE]
What’s your opinion of this? Seriously. I think it’s nuts. LOL
http://www.allbreedpedigree.com/index.php?query_type=horse&h=PLEUNTJE&g=5&cellpadding=0&small_font=1&l=
Traditionally, when a breed ‘runs out’ of healthy individuals to the point outcrossing beyond the limits of the registry is considered, the cross of choice is to an outside mare or group of mares.
It is thought that this works because the RNA for protein synthesis which is transmitted in the cytoplasm and mitochondria of the ovum is ‘new’ to the breed.
This would supposedly add to immune response.
Going to outside stallions does not do this. It does (or can) create performance animals, but does not broaden the base of a breeding population.
This may also be why people say never breed a son back to his dam, but a daughter to sire cross can work. The mare lines are identical in case one, varied in case 2.
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If one looks at other domestic animals: cattle, sheep, etc. most ongoing breeds were formed from a small sire stock and a large and varied dam stock.
Adding in varied sire stock without linebreeding back to the marebase for type? And not adding to or protecting the diversity of the mare base? Not good going into the future.
If and I say IF I were trying to salvage a depressed population I’d be looking for sound, fertile, healthy dam lines a step or 2 out from my breed: related 100-200 years ago, then split off, and proven healthy on range with minimal human interference ‘fixing’ their health issues (no ‘assisted’ animals made it to the breeding population).
I’d breed those to within-breed sires and hope for 3rd and 4th generation animals good enough to include within the breed type parameters.
Crossing types (TB X WB, TB X Morgan, TB x Welsh) creates performance animals but not really individuals to perpetuate the original type breds. And reciprocal crosses (which breed is the mare and which is the sire) DO make a difference; a big one.
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A bottleneck is a bottleneck, whether horses or cheetahs.
10,000 years is a good long time to continue to survive; there are many animals that have gone extinct in that timeframe.
Non-domestic horses, (Tarpan stock) for example.
The immune response issue is based on the antibody combinations that are available in the DNA. Mitochondrial DNA is passed only from mother to offspring but that DNA is the cells energy production this purely important at a cellular level. RNA comes from DNA and is rapidly recycled in the cell so RNA is a reflection of the DNA of the particular individual not it’s parents.
This issue with a bottleneck is less that it determines extinction and more that if a new disease or environmental conditions occurs all animals will be equally susceptible. Essentially animals can become inbred that you are essentially breeding clones to other clones. Genetic variability should be thought of as possibility. There is more possible different phenotypes meaning there is more possible responses to any sort of environmental or disease stress.
[QUOTE=jdeboer01;7214825]
What’s your opinion of this? Seriously. I think it’s nuts. LOL
http://www.allbreedpedigree.com/index.php?query_type=horse&h=PLEUNTJE&g=5&cellpadding=0&small_font=1&l=
How else do you think they set such a dominant type? And stopped the breed from becoming extinct as a purebred?
That “type” had been established LONG before these breedings took place.
[QUOTE=Bats79;7215557]
How else do you think they set such a dominant type? And stopped the breed from becoming extinct as a purebred?[/QUOTE]
That “type” had been established LONG before these breedings took place.
While all breed certainly doesn’t contain all of the Friesian pedigrees, I note that there are no decendants of AGNES after 3 generations listed.
Do you know why? Were they selected against by human taste, or was inbreeding depression resulting in metabolic or reproductive shortcomings?
This is a Ster mare from 1973
http://www.allbreedpedigree.com/hilde22
or this horse
http://www.allbreedpedigree.com/index.php?query_type=horse&search_bar=progeny&h=TEAKE
It appears to me that if the phenotype of these horses is what you want to reproduce in your foals, then the extreme inbreeding of the pedigrees ought to come through on the F1 for dominant characters. As you are producing F1 sporthorses, this is a good thing for predictable marketable foals.
Please state your reasons for objecting to what these horses can offer?
Thanks
You are correct in that “all breed” doesn’t have every Friesian pedigree listed. The actual studbook DOES have offspring listed from Agnes though. I have access to those records as a KFPS member. The breed was, indeed, highly selected against by human taste. “Friesians” were at one time a respected race-winning trotter on par with the likes of what would become Standardbreds. Not all horses who fit the “Friesian” phenotype were recorded once the ‘powers that be’ began actually recording them. There was little motivation to do so. Not every breeder of ‘trotters from Friesland’ was excited about paying fees to a “registry” for questionable benefits. Especially during war times. Those who were running the “studbook” were responsible for some of the hard culls (some most certainly political in nature) of horses with, for example, a spot of white on a coronet, or God Forbid, being a color other than black. (There were indeed Friesians of bay, chestnut, and grey in color at the time the “studbook” was established.) They were selected and culled on phenotype. Actual working or sport ability were secondary.
[QUOTE=D_BaldStockings;7215959]It appears to me that if the phenotype of these horses is what you want to reproduce in your foals, then the extreme inbreeding of the pedigrees ought to come through on the F1 for dominant characters. As you are producing F1 sporthorses, this is a good thing for predictable marketable foals.
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The goals of my own breeding program are more complex than this. And no, my endgame is not simply F1 crosses.
I don’t object to “these horses” per say. I object to their lines continuing in perpetuity in absence of any genetic refreshment whatsoever.
ETA: Just wanted to add, Agnes herself had only two foals, and appears to have likely only lived to be 7 years of age. Either that, they never bred her after the age of 6, which is highly unlikely due to her very high predicate. Her foals would have been valuable. Of those two foals, both fillies, one did not have any offspring (despite a high predicate) and looks to have died by age 5. The other had two fillies, and looks like she may have died by age 6. Either that, the owners were simply not breeding these mares, which I find odd. In any case, the line does continue, but these mares were only having only one or two foals throughout their lives, it seems. Poor fertility, or some other reason? Not sure.
