Inbred stallion prospect- would you dare?

[Rebecca Anderson]

This summer I visited a breeder that had several horses for sale. Among them was a stunning yearling colt and his equally stunning mother. However this stunning, healthy, correct and sound colt is the product of a mother-son breeding, intentionallly done.

The breeder is from Turkey, where he says that such inbreeding is not at all uncommon or frowned upon. He was quite puzzled by our aghast reactions. He is also a medical doctor and no dummy when it comes to genetics and his point was that by making such a cross it is possible to expose recessive problems and if the resulting horse is sound and healthy, then not only does it mean that his mother's line is genetically exceptionally sound, but that he himself should be a very good producer.

When I mentioned that it would be a major problem to find mare owners willing to send their mares to a stallion that was so inbred, he was disgusted and remarked that all we europeans were interested in was making money. But the fact is, that with the taboo we hold against such breeding, it would be shooting yourself in the foot to invest the kind of money is raising and training a stallion prospect and then marketing him when the vast majority of mare owners would never consider sending a mare to him.

However, I have chewed on this for a while now. Of course I am not going to buy the colt, I am not looking for a stallion prospect. The whole concept has intrigued me though. How much of our adversion is based on cultural taboo that we then pack in with psuedo-scientific justification? Does this colt stand a higher than normal risk of producing defect foals (assuming he is used on unrelated mares) than the average stallion, or is he in fact a safer breeding choice after all? Let me add that this breed does not suffer from any of the "sneaky" recessive problems that show up in paints and quarterhorses. Our problems are parrot mouth, cryptorchidism and clubfoot, none of which this colt exhibits.

The colt's dam, who was also for sale, had been bred back again to her son since the breeder was so happy with the result of this first breeding. She two days later produced a beautiful, and defect-free filly. And the colt himself has an exemplary temperament.

Would you breed to a very correct and healthy stallion who was inbred to this extent? If not, why not?

[Astraled]

Sure, I would but I have Arabs. Many WB breeders seem to have an unjustified fear of inbreeding.

I think the breeder is absolutely sound in his reasoning. :)

[FairWeather]

I always thought that the risk of inbreeding was in the resulting offspring, but i'm not so familiar with all of that.
Is there a risk to the offspring of an inbred animal?

[TKR]

It's been done before and will sometimes get a good result and sometimes not. It will produce a concentration of the gene pool being used and "set type" so you are quite sure of what the stallion will produce. In concentrating anything, you will expose the good and bad to a high degree and reproduce the same. If you look at some of the history of Thoroughbred breeding you will see this as well as in other breeds (Arabian) and dogs. I like line/in-breeding when using really good examples and bloodlines, however, that is getting fairly close!
PennyG

[eqsiu]

Inbreeding has been used in all breeds because it helps fix desireable traits in the population. It is not a risk to breed healthy inbred individuals to outcrosses. That is, of course, assuming the inbred individual has no defects. Inbreeding is a way to find out about undesirable traits as well, look at HERDA.

[DMK]

I always thought that the risk of inbreeding was in the resulting offspring, but i'm not so familiar with all of that.
Is there a risk to the offspring of an inbred animal?

I'm thinking if you outcross it, the risk is the same as any other cross. Life's a genetic crapshoot and we never know how those things pair up until it pops out of the womb!

Now if you bred the stallion to another highly similar individual then you have the same issue again. I think the real question the OP should be asking herself is a) Is this a good example of the breed and b) is there enough diversity of bloodlines out there that you can find an outcross or a more distant relative that would be suitable. If you are dealing with a breed that has a limited genetic pool, then all the inbreeding is already done - you probably want to diversify.

[Rebecca Anderson]

Thanks for the feedback. It sounds like you all are more or less thinking the same as me: if the result of a inbreeding is good and healthy, then there is no reason not to use it in *OUTCROSS* breedings.

However, taking it a bit more personally, would you breed your mare to a mother-son bred stallion?

[vineyridge]

Probably not because of the long distance factor in selecting studs. If my mare were around the corner and i could see him every day and I also could know his sister, then maybe. The ONLY reason I might consider it is the Arab success. Hasn't been done in the TB world for about 250 years.

[pwynnnorman]

I'm not sure about the mother-son part--I don't understand the genetics enough to judge whether that's better or worse that half- or 3/4 siblings. However, if the individual were an outstanding speciment, given that prepotency is suppose to be the result of inbreeding, then I'd breed to him, providing his temperament was solidly proven as well.

I wonder, though, if hidden traits other than temperament could be a risk? Or major just a minor one? I'd WANT those superb phenotypical traits that the eye can observe. But what about the inside (cardio-muscular-pulmonary disorders or whatever that one can't see or predict)? Again, though: I'm clueless as to whether that'd be a real risk or whether such issues would have long been bred out of the line being inbred anyway.

I do believe that (edited to...) some of the most successful pony hunter stallions improve mares far, far more consistently because they are inbred (half-sib breeding seems to have been a not-uncommon technique with the top stallions of 10-15 years ago--and now those 10-15 year old sons are superb sires).

[RheinlandPfalzSaar]

However, taking it a bit more personally, would you breed your mare to a mother-son bred stallion?

I personally would not. I am well aware that this is done but just on a personal level it creeps me out, jmo, though.

[tri]

From a purely genetic point of view it shouldn't matter. If we are talking about healthy individuals, you would have to inbreed for typically several generations before the "problems" specific for inbreeding start cropping up.

It has been done as standard practice for quite a few species. For example, all domestic hamsters are a result from three originals so there was a bunch of inbreeding there. Himalayan cats were created by inbreeding to concentrate the long hair + simaese color pattern appearing together.

Inbreeding concentrates characteristics - the good and the bad. If the colt is a very high quality, then there were probably fewer of the bad and more of the good. In a first generation inbred example, characteristics should be all that show up, but not genetic abnormalities attributed to concentrated DNA pools assuming there weren't any genetic abnormalities to begin with.

[tri]

Personally, I'd like to see more line/in breeding in the U.S. In Europe, one reason they have a lot of success is because they do line breed more and they also breed the same cross over and over again so you can compare full brothers and full sisters together. That makes it much easier to REALLY see what a line produces versus basing opinions off of one or two individuals which is what happens more often here. We have much more genetic scatter and less individuals of similar lines to judge what works and what doesn't.

For American breeders to say, "This is what is working here. This line is REALLY producing blah blah blah," we need to see multiple individuals competing who have very similar bloodlines TOP AND BOTTOM and also, see some concentration of those bloodlines to say it is positively that the trait is coming from x,y or z.

[Renae]

It can work, as othrs have said it is common in some breeding programs, here is just an example, the Arabian Raffles, the product of a father-daughter breeding and one of the most influential sires in Arabian breeding in America http://www.arabs-iowa.com/AFH-Raffles.htm

[tri]

Rex Z, I believe, is a product of brother/ sister mating at the Zangershiede Stud in Belgium

[Sassenach]

There was a Connemara farm here in the US called Oak Hills. The owner was a pig geneticist who routinely bred fathers to daughters. While I may not agree with the in-breeding of that closeness (our breed especially needs as much diversity as it can get) I will say that the Oak Hills ponies were a fairly good very regular type of pony.

Would I do it?

Not a chance.

I'm always on the look out for more outcrosses and chances to widen the gene pool rather than bottleneck it. Some of the in-breeding coefficients of the ponies I've seen are horrific.

[YankeeLawyer]

When I mentioned that it would be a major problem to find mare owners willing to send their mares to a stallion that was so inbred, he was disgusted and remarked that all we europeans were interested in was making money.

And he, by homebreeding a dam to the son, is interested in just what exactly?

[eqsiu]

And he, by homebreeding a dam to the son, is interested in just what exactly?

Certainly not the cost of an outside stud fee.

[Rebecca Anderson]

To his defense, the reason he did the breeding was that he had sent his mare out to be bred to an outside stallion (with a very pricey stud fee) and after several tries she was still empty. So in order not to "lose a year" and to she if she *could* get in foal, he used his own (very nice) stallion who happens to be her son.

So it wasn't done to avoid an outside studfee.

[eqsiu]

When I mentioned that it would be a major problem to find mare owners willing to send their mares to a stallion that was so inbred, he was disgusted and remarked that all we europeans were interested in was making money.

It would not be a problem in the QH industry. Many people prefer to linebreed heavily.

[grayarabpony]

Just because the foal looks healthy now doesn't mean that he will be in a year, or 10. Because inbreeding increases all traits, good and bad, I wouldn't use him.

[tri]

If your concern is having something like a heart valve defect, etc, why would you think a horse not closely bred would have a better chance of not throwing it than a horse that is closely bred? If it is there, it is there and you might not know it in both cases. If you have healthy stock to start with that have proven themselves in performance, there would be no reason to think otherwise.

Going back to Rex Z. Both his dam and sire (full siblings) were major int'l level jumpers - some of the best in the world. Rex Z himself went on to compete at GP level.

[grayarabpony]

If your concern is having something like a heart valve defect, etc, why would you think a horse not closely bred would have a better chance of not throwing it than a horse that is closely bred? If it is there, it is there and you might not know it in both cases. If you have healthy stock to start with that have proven themselves in performance, there would be no reason to think otherwise.




Simply because of the concentration of genes.

[Sugarbrook]

I know that long time, very admired pony breeder Marilyn Checki at Hillcrest Farm did that type breeding with success many times. Gayfields Vida Blue, her stallion, sired many many famous show ponies and he himself has been #1 or #2 for the last few years in pony hunter breeding. Must have worked for her. I havent done it yet.....yet. Have pondered the idea.

[tri]

I guess my point is, grayarabpony, is that if the worry is that everything looks great externally but you are concerned with something internal that you couldn't see - that could be the case with a stallion or mare that is NOT closely bred as well. The mere fact that the horse is closely bred for one or two generations doesn't mean that there is a higher chance that there is something internally wrong.

Whereas, horses that are closely bred for a couple of generations, might give you a BETTER chance of NOT having a problem because it would have shown up BECAUSE of the concentration and you would have the knowledge rather than being at the mercy of genetic scatter where it just suddenly pops up out of seemingly no where.

[ParadiseFarm]

Tri,

To follow up on the theory part here - Rex Z was the product of full brother to full sister - and he did compete at GP level - but he was not nearly as accomplished as either the sire or the dam.

So if the intention is to carry forward the desirable genetic traits, did it work? That is, is Rex Z's performance less important because he has/throws the genetics...or does he invalidate the close-breeding concept to a certain extent? since he did not equal or exceed the parents?

Appreciate your thoughts here as I often wonder if the production of a breeding animal and the production of a performance animal are somewhat mutually exclusive....

[grayarabpony]

Tri,
Of course there's a better chance of something going wrong with breeding closely related individuals than breeding individuals who are not closely related. I'm sorry but what you wrote just doesn't make any sense, genetically.

[Rebecca Anderson]

I don't think the issue here is the danger of breeding closely related individuals, the issue is the breeding potential of the resulting offspring.

[summerhorse]

Inbreeding is a tool like many others. This cross is common in other breeds and species. In fact bulls are routinely tested by breeding them to 100 of their daughters to see if anything bad shows up, if it does, he's hamburger. If not he gets a chance.

As long as you OUTCROSS the resulting foal (most 'bad" genes are going to show up in the foal, there may be some that could be carried on just like any horse and show up later). If the foal is healthy and fine now he should be fine later unless he has inherited some bizarre genetic disease or defect that was unknown up til then. And at least then they will know about it!

Now if you kept ON breeding these closely related individuals then you could very well see problems start to crop up as the gene pool gets smaller and smaller. it increases the chance that a bad gene will show up as well as the chance it will be very detrimental to the breed.

Most people (Americans) think INCEST when they see inbred animals but horses are not people, they do not have a problem with relatives breeding. They could care less.

I think if the colt is well bred (regardless of his parentage) and then PROVES himself to be an outstanding show horse (or whatever) then people will breed to him. The owner could increase confidence by not allowing mares with similar breeding in to his book. If his foals are outstanding people will want one. He just may have to work a little harder. I have noticed that a lot of WB and hunt type stallions have not a whole lot of show record to back up their pedigrees in the states (it seems by perusing ads). So it may help a LOT to have that horse out there competing a lot showing how nice and wonderful he is. People will see him and want to breed to him before seeing his pedigree and getting all freaked out.

[Thomas_1]

I'm absolutely fine with linebreeding but not inbreeding.

Line breeding is actually what THE BEST horses and dogs are. And I mean PROVEN best.

Line breeding is about planning to double up on the best genetic traits possible.

It requires detailed knowledge of pedigrees and genetic disposition, conformational traits and possible inherited defects. Basically by Line breeding you double up on everything - so you have to be CERTAIN you're doubling up on good and that the specimens are the best possble and with nothing bad to double up on.

All our golden retrievers are line bred: This means we consistently produce champions. Not just producing exceptional show dogs but also excellence in the field as working gun dogs. They're hip scores (for displasia) are extraordinarily low, they don't carry PRA or hereditary cateracts and they are virtual "clones" of each other.

Likewise my race horses are all line bred - mine happen to go back to the top winning national hunt stallion "Strong Gale". I've mentioned him before and a heck of a lot of top jump race horses and eventers are bred back to Strong Gale. My best ever horse had Strong Gale as his Grand Sire on both the Sire and Dam's side of the pedigree.

Same for my cattle and sheep - my best and most valuable stock are Line Bred.

Its important to appreciate that animal husbandry and particularly producing the BEST stock is not an accident, its a science and Line Breeding is how its done.

However a mother:son is inbreeding that IMO is way too close and dangerously reduces the genetic difference and whilst the horse may well be o.k, it renders him absolutely useless as a stallion because of the closeness of his breeding.

[tri]

"Tri,
Of course there's a better chance of something going wrong with breeding closely related individuals than breeding individuals who are not closely related. I'm sorry but what you wrote just doesn't make any sense, genetically."

Greyarabpony, is it starting to make more sense now that several others have weighed in? With closely bred horses, you have a better chance of knowing exactly what you will get. You know that BECAUSE it is concentrated, that the chance of something weird out of the blue popping up are reduced. With outcropping, you are back to at least some genetic scatter and a bigger chance that something you weren't expecting will pop up.

[pwynnnorman]

It can work, as othrs have said it is common in some breeding programs, here is just an example, the Arabian Raffles, the product of a father-daughter breeding and one of the most influential sires in Arabian breeding in America http://www.arabs-iowa.com/AFH-Raffles.htm

What I have never gotten over, Renae, is how Raffles himself for used for the most intensive inbreeding--probably the world record of inbreeding of all breeds. It's just amazing to me how many times an Arabian can have Raffles in it. I've noted this before, but my foundation mare's sire has NOTHIGN but Raffles in him four generations back. He is virtually Raffles (Well, should have been, I guess--it'd be interesting to have a picture of him and compare it to Raffles to see what genetic drift occurred or whatever you call it after inbreeding to the same inbreeding, etc., etc. What an extraordinary individual he must have been.)

BTW, Hackney ponies are, like hamsters (I thought that quite funny) products of inbreeding to stamp desirable traits. It is also theorized by some that Figure (Justin Morgan's original) was the product of inbreeding somewhere (because he was so prepotent and because he was small--according to what I've read, inbreeding tends to result in smaller individuals).

[tri]

"To follow up on the theory part here - Rex Z was the product of full brother to full sister - and he did compete at GP level - but he was not nearly as accomplished as either the sire or the dam."

Unfortunately, nothing that Ratina Z has produced has come close to what she is/was linebred or outcropped....and that would be a pretty tall glass to fill to, wouldn't it? There will only be one Ratina Z!

[grayarabpony]

No, tri, because the rest of it sounds like nonsense too.

Dogs are not a good example for linebreeding at all -- look at all of the problems among dog breeds.

[PineTreeFarm]

Here's an interesting TB pedigree

http://www.allbreedpedigree.com/index.php?query_type=horse&h=HIGH+TIME&g=5&cellpadding=0&small_font=1&l=

Domino died early as did his son Commando so it appears that the breeding was to consolidate as much of a rare bloodline as possible.

Ultimus and High Time were both successful as sires.

[ahf]

I think that the problems associated with inbreeding and linebreeding are frequently understood only when it's WAY too late. Generations down the road. For instance:

"Hyperelastosis cutis causes quarter horses' skin to weaken, wound easily and heal poorly with disfiguring scars.

Dr. Ann Rashmir-Raven, an associate professor in MSU's veterinary college, said her research shows that years of breeding closely related American quarter horses to obtain desirable traits actually caused this devastating skin disease in the breed.

"All of the horses diagnosed with HC are related," Rashmir said. "As is common in breeding programs, closely related horses were bred in the hopes of producing better-performing horses. Because of the popularity of sires that are or were carriers and the use of assisted reproductive technologies, it is likely that the HC gene is present in thousands of horses."

[tri]

You can't compare poor breeding practices against the success that so many have. Look at humans - americans in general - not much inbreeding there - lots of genetic scatter - yet we have more and more eye problems, not the least of which is near sightedness, crooked teeth, poor conformation, pre-disposition to heart disease, obesity, the orthopod community announces that few americans have well formed feet causing a larger and larger need for orthotics - all without much inbreeding or linebreeding.

[vineyridge]

There's a huge difference between linebreeding in the 3rd and after and in breeding (or incest.) There's a big difference between grandfather and granddaughter. I'd have to know an awful lot about the mother's lines before I'd use a mother-son stallion.

[goodmorning]

Dogs are not a good example for linebreeding at all -- look at all of the problems among dog breeds.

Having worked with some of the best (think multiple Westminster Champion's in many different classes) dog breeder's in the world, and some of the worst, I can tell you that majority of the problems among dog breeds exsist due to the 'breeders.'

[YankeeLawyer]

It would not be a problem in the QH industry. Many people prefer to linebreed heavily.

And many believe that QHs have suffered as a breed because of it.

[YankeeLawyer]

the orthopod community announces that few americans have well formed feet causing a larger and larger need for orthotics

Now there is an unbiased source -- the orthopod community regarding the need for orthotics???

[J-Lu]

To follow up on the theory part here - Rex Z was the product of full brother to full sister - and he did compete at GP level - but he was not nearly as accomplished as either the sire or the dam.

So if the intention is to carry forward the desirable genetic traits, did it work? That is, is Rex Z's performance less important because he has/throws the genetics...or does he invalidate the close-breeding concept to a certain extent? since he did not equal or exceed the parents?


I'm not a fan of inbreeding, which is different than line breeding. I'm not sure that I'd breed my mare to an inbred horse, but I'd also say that a one-generation in-breed wouldn't necessarily scare me away.

Holsteiner people help me out: who was it who is rumoured to be the product of brother-sister mating? Capitol I? The C line horse I'm thinking of (wasn't it Capitol I?) was extremely successful as an athlete and sire even though his supposedly full brother (who was actually outbred) Capitol II was not nearly as successful. Many, many foals came from this successful sire and there didn't seem to be a huge incident of genetic anomalies. However, I'd be VERY careful about how I bred the offspring...

J.

[LLDM]

Crimany people, we know inbreeding is a bad idea. Google "inbreeding" and "genetics" and the first article is from Youngstown State University:

http://cc.ysu.edu/~helorime/inbredgen.html

Lays it out pretty simply - especially this page the page on "Inbreeding and its General Effects" and "Inbreeding Effects on the Immune System".

SCFarm

[ParadiseFarm]

I'm not completely sure, but I think the question stems from Capitano, Capitol's sire. The controversy is whether Capitano's sire was Corporal (as officially listed) or Grand Vicar (widely accepted).

I think the issue has to do with Capitano being homozygous for grey, with Corporal being bay and Grand Vicar being grey.

In the alternative scenario, Capitol is double Vase and triple Ramzes in the 3rd through 5th generation with gender balance - kind of textbook linebreeding....

I really don't know the specifics, but if someone does, please clarify this!

[eqsiu]

And many believe that QHs have suffered as a breed because of it.

Ya think? But my horse has 9 crosses to Impressive! LOL!

[YankeeLawyer]

Ya think? But my horse has 9 crosses to Impressive! LOL!

I think it is a shame, because I really love QHs. It is really hard to find a good one now.

[carolprudm]

I guess my point is, grayarabpony, is that if the worry is that everything looks great externally but you are concerned with something internal that you couldn't see - that could be the case with a stallion or mare that is NOT closely bred as well. The mere fact that the horse is closely bred for one or two generations doesn't mean that there is a higher chance that there is something internally wrong.

Whereas, horses that are closely bred for a couple of generations, might give you a BETTER chance of NOT having a problem because it would have shown up BECAUSE of the concentration and you would have the knowledge rather than being at the mercy of genetic scatter where it just suddenly pops up out of seemingly no where.
Yup
If the stallion and his dam looked good and especially if they looked a lot alike and they complimented my mare (sharing none of her bad points) I would certainly breed to an inbred stallion.
However if they shared ANY undesirable charactersitic I would pass

[PineTreeFarm]

And many believe that QHs have suffered as a breed because of it.

It depends what you mean by 'suffered'. Line breeding with Impressive certainly produced the type that is sought after for Halter classes. So from that point of view linebreeding certainly worked. The bad part was that it brought along a genetic disease. If HYPP hadn't come along for the ride I'm not so sure anybody would be complaining about line breeding in QH's.

There are basically three types of QH's today, Halter, Working and Racing.
Racing QH's in general don't have much Impressive breeding so it's pretty easy to avoid that bloodline. And the racers are more a sport horse type anyway.

[DMK]

Tri,
Of course there's a better chance of something going wrong with breeding closely related individuals than breeding individuals who are not closely related. I'm sorry but what you wrote just doesn't make any sense, genetically.

No, not exactly. If both individuals share a desirable or undesirable trait, there is a better chance of it showing up in offspring (and since they are related, there is a greater chance). If neither individual has the trait, then there is (obviously) less chance of it showing up. The way you phrased it made it sound like any multitude of problems were likely to show up strictly by virtue of line or inbreeding.

As a side note, I always liked the phrase by Hank Wiescamp, who is a fairly famous QH breeder back in the day (he bred Skipper W). His famous phrase was "When it works, it's called 'linebreeding' ... when it doesn't it's called inbreeding." Oh maybe not scientifically accurate but since he was credited with it maybe half a century ago, he gets the nod for intent.

Here's a classic example of Hank Wiescamp Skipper W breeding

skip beau (http://www.allbreedpedigree.com/index.php?query_type=horse&h=SKIP+BEAU&g=5&cellpadding=0&small_font=1&l=)

[grayarabpony]

Yup
If the stallion and his dam looked good and especially if they looked a lot alike and they complimented my mare (sharing none of her bad points) I would certainly breed to an inbred stallion.
However if they shared ANY undesirable charactersitic I would pass

The problem is, you can't just go look at a stallion and tell that he's OK. Or he may pass on a problem that he doesn't have when very young, but his offspring might. This could happen with any stallion but is more likely to happen with an inbred stallion. Genetics is a crapshoot anyway, why do something especially risky?

As long as we're throwing out random examples, Secretariat was a complete outcross.

[carolprudm]

The problem is, you can't just go look at a stallion and tell that he's OK. Or he may pass on a problem that he doesn't have when very young, but his offspring might. This could happen with any stallion but is more likely to happen with an inbred stallion. Genetics is a crapshoot anyway, why do something especially risky?

As long as we're throwing out random examples, Secretariat was a complete outcross.
And not a particularly good sire.

Horses who are inbred from GOOD parents who do not share common faults, hidden or not and no more likely to carry hidden flaws than any other sire

[DMK]

As long as we're throwing out random examples, Secretariat was a complete outcross.

Oooh, one good random example deserves another. His far more influential great grandfather (the Tesio bred Nearco) was most decidedly not a complete outcross. We could go all day with this! :lol:

[eqsiu]

And not a particularly good sire. (Re: Secretariat)



But a very good broodmare sire.

[arnika]

So I have to ask, which is the QH bloodline that is thought to carry HERDA? One of the abstracts lists cutting horses but nothing more specific.

[grayarabpony]

Secretariat was not as good a sire as he was a racehorse, but he was a good sire, especially as a broodmare sire. Also, there are several very good jumpers descended from him.

Yes, Nearco has some inbreeding, especially to St. Simon, but it is 4 and 5 generations back. It's not as though he's the result of a sister bred to a brother.

That's silly to say that inbred horses do not carry more "hidden" flaws than other horses. There is no genotype that does not carry some flaws. The more concentrated that gene pool becomes, the more flaws that horse will carry along with the desired traits. It's not possible to wean out all of the flaws without getting rid of a lot of foals that probably are not good at all along the way. Why not breed 2 unrelated horses with good qualities? Less chance of something horrible happening.

[Rebecca Anderson]

The more concentrated that gene pool becomes, the more flaws that horse will carry along with the desired traits.

There are the same number of genes in an inbred individual as in an outcrossed individual. I don't think it is a given that the more inbred the horse is, the more flaws it will carry genetically.

[eqsiu]

So I have to ask, which is the QH bloodline that is thought to carry HERDA? One of the abstracts lists cutting horses but nothing more specific.

Poco Bueno.

[DMK]

yes, the math on this runs both ways. Yes, the horse could be more predisposed to genetic conditions IF both parents possess the genetic trait. If neither parent possess those flaws OR strengths, then the offspring is less likely to carry it. You can't hang your hat on the flaws argument without granting equal weight to the strengths argument.

And no, I didn't mean Nearco to be an example of inbreeding, he clearly is not. It's just he is in no way a total outcross, and yet exhibits tremendous influence on the breed.

Arnika, I think it may be Poco Bueno lines that are predisposed, but I'm working off a dusty memory so I might be wrong.

[PineTreeFarm]

http://www.bringinglighttohypp.org/HERDA.html
Info on HERDA.
There is a test available through UCDavis.

[ahf]

And a better indictment of incessant linebreeding I’m not sure I’ve read. Thank you for that link. There are unintended consequences for everything we do in life. And it’s VERY clear Mother Nature does not like too much of a good thing.

And yet, in a previous post you say “ Line breeding with Impressive certainly produced the type that is sought after for Halter classes. So from that point of view linebreeding certainly worked. The bad part was that it brought along a genetic disease. If HYPP hadn't come along for the ride I'm not so sure anybody would be complaining about line breeding in QH's.“

So you think that HERDA is a one-off? Just a cosmic fluke? If you are tired of exploring QH genetic diseases we can move on to Arabian or Mountain Curley’s if you’d like….

I’m keeping quiet about HYPP, as the prevalent thought now is that it is the result of breeding for a certain trait (precocious muscle mass), not the result of inbreeding per se. Though I have my doubts, I’m bowing to the geneticists on this subject.

[grayarabpony]

You can't hang your hat on more strengths if there's also more weaknesses. And the more inbreeding, the greater the liklihood that weaknesses will also be concentrated. This isn't about one gene. It's about many, many genes, and their modifying genes. Like I said earlier, what about all of the problem horses that will have to be culled. Hardly worth it, IMO.

As far as Nearco, I've often wondered if Nearco has also contributed to the incidence of aneuryisms in the TB in addition to speed. He either died from an aortic aneuyrism or a ventricle blow-out, and aneuyrism is not an uncommon cause of death in TBs. In humans aneuryisms often have a strong genetic component.

[rcloisonne]

What I have never gotten over, Renae, is how Raffles himself for used for the most intensive inbreeding--probably the world record of inbreeding of all breeds. It's just amazing to me how many times an Arabian can have Raffles in it. I've noted this before, but my foundation mare's sire has NOTHIGN but Raffles in him four generations back. He is virtually Raffles (Well, should have been, I guess--it'd be interesting to have a picture of him and compare it to Raffles to see what genetic drift occurred or whatever you call it after inbreeding to the same inbreeding, etc., etc. What an extraordinary individual he must have been.)
And here's a horse, considered one of the best of his time, Lewisfield Sun God. He's the result of a *Raffles son on a *Raffles daughter - full sibs no less. ;) Sunny didn't growing horns anywhere and if he were alive today, I'd breed to him in a heartbeat. Unfortunately, he was lost to the breed at 7 years old due to crippling laminitis.

http://www.allbreedpedigree.com/lewisfield+sun+god

Check out the photos section to see the "progression".

[pwynnnorman]

Genetics is a crapshoot anyway, why do something especially risky?

Because some folks are very, very highly motivated to produce the best possible athlete and because they (not me, I ended up with an athlete with an entire line of inbreeding in his pedigree wholely through ignorance of how his granddam was produced) felt an exceptional animal was worth the risk.

Look, it doesn't make sense to ignore what others have already done. That article someone posted the link to ignores the fact that IT'S BEEEN DONE SUCCESSFULLY. Yes, there are risks, but as I stated before, have you looked at how many top, top pony hunter stallions have the same grandsire top and bottom? And do you choose to ignore the Hackney pony--and entire breed produced via inbreeding? Besides being hot, where are the "immune issues" that article mentions?

It's necessary to qualify statements, including pseudo-scientific ones. I have never, ever, ever, ever heard of half-sib crosses having immunodefficiency issues. Ever. I suspect what that article meant was "excessive inbreeding" (like, IMO, what Arabian folks risked with Raffles).

I think some of you might want to just think it through a bit more before judging all inbreeding too harshly. SOME inbreeding efforts have advanced the quality of horseflesh in incredible ways. (And some have doomed it, yes--but does anyone know how much inbreeding resulted in those problems (HERDA, HYPP, lethal white, etc.). I'm wondering whether those represent the excess issue not the simple...F1...mating??? Is that how you'd refer to using half-sibs? F1? Or would it be F2? never did quite get how that is applied.)

[RiddleMeThis]

GrayArab-You can get genetic problems in out cross breedings as well. Close or inbreeding concentrates genes, but it does not have to concentrate the bad genes. It can but it does not have to. You could breed mother and son father daughter brother sister and they could pass on none of their supposed bad traits.

[pwynnnorman]

http://www.allbreedpedigree.com/lewisfield+sun+god (http://www.allbreedpedigree.com/lewisfield+sun+god)


rcloisonne, what I find fascinating about that horse's pedigree is that although he's the product of full siblings, those individuals were themselves products of your classic "inbreeding to outcross." Correct me if I'm wrong, but I didn't see a single common individual between Raffles and Aarah in that pedigree.

[rcloisonne]

rcloisonne, what I find fascinating about that horse's pedigree is that although he's the product of full siblings, those individuals were themselves products of your classic "inbreeding to outcross." Correct me if I'm wrong, but I didn't see a single common individual between Raffles and Aarah in that pedigree.
A most excellent an astute observation, pwynnorman. And it's a mighty good thing that Lady Ann Blunt didn't live to see horses of such prime Sheykh Obeyd bloodlines bred to the likes of *Raffles, inbred son of the "kaddish" Skowronek. She would have been appalled. :winkgrin:

[DMK]

You can't hang your hat on more strengths if there's also more weaknesses. And the more inbreeding, the greater the liklihood that weaknesses will also be concentrated.

Again, the weaknesses have how much more mathematical probability than the strengths? And what happens if the weaknesses are negligible? What then? What if the strengths are exceptional? What then? You argue this equation like it has only one outcome. That just simply isn't the case. It is a high risk/high reward equation, and not to be done without knowledge and planning, but you just can't argue the only outcome is the "weaknesses always trumps strengths" equation. All those thousands of genes won't let you (and yes, I think most of us have grasped the idea that there is more than one. Might even be 20,000 or some silly number like that).

[vineyridge]

rcloisonne, what I find fascinating about that horse's pedigree is that although he's the product of full siblings, those individuals were themselves products of your classic "inbreeding to outcross." Correct me if I'm wrong, but I didn't see a single common individual between Raffles and Aarah in that pedigree.

Berk, Risala and Mesaoud are top and bottom in Aaraf and Aarafa. Maybe I'm not understanding what you and rcloisonne are seeing-or not seeing.

On the main issue, though, Temple Grandin has a lot to say about unintended and invisible consequences of inbreeding for specific physical traits. Of course, the pecularities don't show up until many generations of tight inbreeding later, but some of them are truly bizarre.

Edited to add--perhaps Sunny's crippling laminitis that got him at seven had a genetic component. We won't ever know, will we?

[YankeeLawyer]

It depends what you mean by 'suffered'. Line breeding with Impressive certainly produced the type that is sought after for Halter classes. So from that point of view linebreeding certainly worked. The bad part was that it brought along a genetic disease. If HYPP hadn't come along for the ride I'm not so sure anybody would be complaining about line breeding in QH's.
.

The point is that HYPP *did* get passed along, in spades.

[stolensilver]

My view on inbreeding is to avoid it. People here are asking where are the diseases caused by inbreeding? Where is the proof of decreased lifespan and reproduction?

The data is not as easy to find in horses but it is there if you look hard enough. There is a strong possibility that laminitis has a genetic component. TBs are highly inbred with a limited gene pool. They get cripplingly painful laminitis that is life threatening from a far smaller degree of founder than any other breed.

Decreased lifespan? Definitely true. We "expect" competition horses to have an average lifespan of about 20 years. Naturally bred horses (competition horses tend to be selectively bred) with wide gene pools live 30+ years. This doesn't impact on most horse owners as we are happy with a lifespan of 20 years. It is a big reduction though.

Decreased fertility? Definitely true. How many big name stallions (TB and WB) can you think of who were failures at stud? How many times do breeders have problems getting their mare in foal? Domestic horses have a 60% chance of producing a healthy foal if you start with two healthy parents. This is the worst reproduction figures of any domestic animal apart from elephants!

Finding out what inbreeding has done is much easier in dogs. This link provides interesting reading. Basically every single pedigree breed of dog has genetic diseases. Golden Retrievers get cancer at an early age. Staffies get early cataracts. German Shepherds get degenerative myelopathy. Look at the list of diseases. It is frightening. We all know that mutts in general are healthier and live longer than pedigree dogs.

The science behind inbreeding is the same whether the gene pool is mice, dogs or horses. Most of the diseases made commoner by inbreeding will not be simple autosomal dominant or recessive inheritance (like HYPP dominant or HERDA recessive) they will be due to the interaction of many genes but that does not mean they are not due to contraction of the gene pool. Did you know that it is the immune system that protects us and animals from cancer? Our bodies produce cancer cells on a daily basis. Our immune systems recognise the cancer cell and kill it. If the immune system is impaired cancer levels go up.

I know inbreeding can work otherwise no one would do it. But long term it leads to weaker individuals with health problems, fertility problems and shorter life spans. Something to think about is OCD. We all know it is a problem in warmbloods. Look at the number of inbred dog breeds with OCD type diseases. Don't you think there is at least a possibility that OCD has a genetic component?

http://www.handicappedpets.com/genetic/diseases.htm

[rcloisonne]

Berk, Risala and Mesaoud are top and bottom in Aaraf and Aarafa. Maybe I'm not understanding what you and rcloisonne are seeing-or not seeing.
I can't speak for pwynnnorman, but what I see is that Raffles was bred to a mare (Aarah) that was not closely related (in Arab breeding anyway) although his second dam (Rissla) certainly was. So yes, this was not a complete out-cross.

Edited to add--perhaps Sunny's crippling laminitis that got him at seven had a genetic component. We won't ever know, will we?
I think it’s pretty much a given that insulin resistance is hereditary. It is a useful survival mechanism found in breeds selected to exist on little sustenance for centuries. When these animals are put in situations where access to high quality feed and pasture is basically unlimited, it’s not so surprising their physiology runs amok, resulting in laminitis.

“Sunny” (and I made that up, no idea if that’s what this horse was called by his connections) initially foundered at age 3! Unless the cause had been a febrile systemic illness (such as Strangles or EI) I suppose a case could be made that inbreeding contributed to the pathology. BTW, this line is still being inbred! :eek:

http://www.pharaheritagesociety.com/index_files/LewisfieldSunGod.htm

It is my belief nearly all purebred Arabians are at a greater than average risk of developing laminitis sometime in their lives if not properly managed. That said, despite the fact Arabians have a much higher inbreeding co-efficient than that of other breeds, most of them are fertile, sound and generally live to a ripe old age. ;)

[pwynnnorman]

Again, critics are not distinguishing the one-off from the repeated.

Producing ONE stallion that is the result of inbreeding and then OUTCROSSING him (not, not, not continuing to inbreed!) is what I've been defending and what I'm trying to point some to as having been one whopper of a successful technique. Again, if you are trying to develop an exceptional product, you want both hybrid vigor and genetic stability. That has been the rationale for "inbreeding to outcross" among not only animals, but plants, too, as I understand it.

Downland Dresden, dam of the oh-so-influential Carolinas Red Fox: http://www.allbreedpedigree.com/carolinas+red+fox

Land's End Poseidon (look at how many times Downland Chevalier appears in his pedigree!): http://www.allbreedpedigree.com/lands+end+poseidon

Downland Kruggerand: http://www.allbreedpedigree.com/downland+krugerrand

Rowfantina Gold Sovereign: http://www.allbreedpedigree.com/rowfantina+gold+sovereign

Halcyon Sir Lancelot: http://www.allbreedpedigree.com/halcyon+sir+lancelot

Rambur Seven: http://www.allbreedpedigree.com/rambur+seven

Downland Drummer Boy: http://www.allbreedpedigree.com/downland+drummer+boy

Dowland Rembrandt: http://www.allbreedpedigree.com/downland+rembrandt

Cusop Jovial: http://www.allbreedpedigree.com/cusop+jovial

Ardmore Traveller (several examples in his pedigree): http://www.allbreedpedigree.com/ardmore+traveller

Salvandi Calidog: http://www.allbreedpedigree.com/salvandi+calidog

Talimo Cricket: http://www.allbreedpedigree.com/talomo+cricket

And last, but not least, perhaps the most famous and successful of all, the double-bred (euphemism for inbred) grandson of the most influential pony hunter in history (Farnley Lustre),
Blue Rain: http://www.allbreedpedigree.com/blue+rain

Now, you may wonder if I just picked these pony hunter stallion (mainly) names out of a hat or something). I didn't. I just went down the leading sires list. Curiously, though, it was more often than not the SIRES or DAMS of the leading sires, not the leading sires themselves who were the product of half-siblings. Now to me, this provides support for "inbreeding to outcross" yet again: Sires who are the products of an inbred animal crossed on a different line are some of the most successful sires. Blue Rain is the exception.

Heard of any genetic malaise in the pony hunter industry? I haven't. What I've seen in a continual refinement of the type--through inbreeding, linebreeding and outcrossing (outcrossing both pony lines and also horse breeds, i.e. Downlan to Coed Coch or Bowdler; Welsh to TB or Arab)--to the point where it would take a stranger no time at all to figure out what a top quality pony hunter's traits were. And look what it's done to the market, too. That is the positive evolution of breeding, IMO: Finding what works, concentrating it, and then crossing it for vigor.

These are facts, but folks will continue to ignore facts and just go with their gut feelings--such is the nature of the majority in the horse biz and such is why an inbred stallion openly promoted as such would never succeed, IMO. Another fact is that few folks are actually breeding thoughtfully to produce the exceptional animal. They are just breed to "produce" (their personal preferences). I think there are breeders in many, many breeds and species who would have some significant arguments against THAT to the same extent that--and with all do respect, folks: I'm just enjoying debating this issue, one I've thought about a lot--others argue against inbreeding.

[grayarabpony]

Sunny's a great example. :rolleyes:

I agree with stolensilver. When I breed I want fertile, sound, healthy, long-lived individuals, not something that can last for a few years in one specific discipline. Again, with the hackneys and the show ponies, how many culls had to be thrown out? There were probably some horrific ones. How can you ignore that?

BTW, I looked up my pony's sire's pedigree, as she's half Arab, and was relieved to see that he's not highly inbred.

Gut feeling has nothing to do with this. And yes, I do have a biology degree.

[pwynnnorman]

Again, with the hackneys and the show ponies, how many culls had to be thrown out? There were probably some horrific ones. How can you ignore that?

I believe, initially, you are right with hackney ponies, but that is no longer the case. In all breeding efforts, regardless of species, you have to cull what doesn't work and keep working with what does. Hackneys do not suffer from the genetic problems found in AQHA's etc., as far as I know. Nor did the Raffles inbreeding efforts result in major problems. And again, grayarabpony, you don't seem to be distinguishing between doing it ONCE and doing it repeatedly. There is no evidence whatsoever in pony hunters that there are a lot of culls being "thrown out." That is because the inbreeding that exists has been tempered wisely by outcrossing.

Have you any idea of how much of the food you eat that are the product of this (kind of) relationship?

From: http://www.ext.vt.edu/pubs/dairy/404-080/404-080.html#idp The critical issue is whether inbred dairy cows are functional under today’s management conditions and whether that functionality is compromised by less genetic diverstiy in the population. Cattle today are more inbred than their ancestors, but they are also much more productive. It would not be accurate to say that current levels of inbreeding are alarming.

Indeed, I suppose one could even explain Blue Rain this way, as he is 3/4 Welsh, 1/4 TB. The potential danger of half-sibling matings (as well as other matings among close relatives) also depends on the degree of prior inbreeding of the sire and the two dams involved. For instance, breeding two individuals that have the same sire is less likely to be problematic if the two dams are distantly related (e.g., one from the Yates family and one from the Butler family) than if the two dams are closely related (e.g., both cousins from the Butler family).

[carolprudm]

I do have a biology degree.

As do I, and I support CAREFUL in or linebreeding

[Annetta]

Why not breed 2 unrelated horses with good qualities? Less chance of something horrible happening.Not really. If you use a stallion that is heavily line bred, or even inbred, assuming that the horse is a good quality individual, you know more what you are going to get in the foal--regardless of what mare that stallion is bred to--than you do if the stallion is a product of nothing but outcrossing.

Morgan breeders do a lot of linebreeding and inbreeding. Father to daughter is the most common cross, not so much mother to son (for some reason that is a weaker cross but I've really never understood why) and of course it's common to breed paternal siblings. If the stallion is inbred or heavily linebred, he will reproduce himself--you will see him in his foals. If you use an outcross stallion you have a whole mixed bag of genes and you just don't know which ones are going to get pulled out of the bag for his foals. Often such a stallion doesn't show any consistancy in his offspring.

Obviously if you are going to breed father to daughter or mother to son you want to start with the best individual you can find. You do not want to double up on any obvious flaws. Does the stallion have a weak croup? If so, and you breed him back to his own daughter, chances are the resulting foal will have a croup that is much, much worse than the sire's.

Line breeding (or inbreeding) brings out the recessive genes. If there is a recessive gene hiding in a stallion, if you breed him back to one of his daughters chances are that recessive gene will show up in the foal. This is why if one is going to practice inbreeding or line breeding, one must be prepared to cull. One should always be prepared to cull, but it's even more important in linebreeding/inbreeding.

If the father to daughter (or mother to son) cross produces an outstanding individual I personally would be quite confident when it comes to using that offspring for breeding. Assuming that the horse has the attributes I want--looking at conformation, movement, attitude, type--then yes, I would buy the horse (or breed to him).

Keep in mind that just because there are some inbred horses that I don't like, doesn't mean that the inbreeding failed--it just means that the breeder was breeding for type or conformation different than what I would go for (Thinking Morgans here--I like the old type or sport horse type, so there are some inbred/linebred show type horses that I just don't go for.)

As someone else said earlier in regard to QHs--halter type QHs for instance some feel are hideous examples of horses. That big bulky build is not because they are linebred, it is because of the type of horse that the breeders chose to do their line breeding with.

[Sonesta]

There is an ongoing and long term project (headed by Dr. Sue McDonald) at Univ. of PA New Bolton using semi-feral pony herds that indicates that wild horses do not tend to breed to close relatives. In the herds, the herd stallion does not breed his own daughters. When they become sexually mature, these fillies wander from the herd and "select" their mates from the wandering bachelor stallions. And they always seem to select the most distantly related stallion for a mate.

[DMK]

As someone else said earlier in regard to QHs--halter type QHs for instance some feel are hideous examples of horses. That big bulky build is not because they are linebred, it is because of the type of horse that the breeders chose to do their line breeding with.


bing bing bing - we have a winner! Line breeding isn't the problem, it's the decisions made in that particular example. But when it comes to horses bred to stand on the end of a line and nothing else, I do believe any breeder could ruin a breed with or without linebreeding. It might just take them one or two more generations, but never doubt our ability to modify the animals that serve us.

[tri]

"TBs are highly inbred with a limited gene pool. "

No, they are not. Matter of fact, that is one of the biggest complaints from the europeans on using too much TB blood - TOO MUCH genetic scatter.

Somebody please send my all the Farnley pony culls!!!!!

[stolensilver]

TBs are descended from 3 stallions and 25 mares. How is that not highly inbred?

http://www.newscientist.com/article/dn7941.html

Quote: "Prof Cunningham examined the genetic profiles of thoroughbreds alive today and found they were descended from only 28 horses. Ten of these accounted for 80 per cent of those alive today.

A horse that lived in the late 17th century called Tregonwell's Natural Barb Mare was identified as an ancestor of 14 per cent of living female thoroughbreds.

Thoroughbreds cannot by definition be the offspring of non-thoroughbred horses, so the population is becoming progressively more in-bred.

Prof Cunningham said the proportion of genes shared by any two thoroughbreds had risen from 31 per cent two centuries ago to around 47 per cent now."

[Drvmb1ggl3]

TBs are descended from 3 stallions and 25 mares. How is that not highly inbred?

http://www.newscientist.com/article/dn7941.html

Quote: "Prof Cunningham examined the genetic profiles of thoroughbreds alive today and found they were descended from only 28 horses. Ten of these accounted for 80 per cent of those alive today.

A horse that lived in the late 17th century called Tregonwell's Natural Barb Mare was identified as an ancestor of 14 per cent of living female thoroughbreds.

Thoroughbreds cannot by definition be the offspring of non-thoroughbred horses, so the population is becoming progressively more in-bred.

Prof Cunningham said the proportion of genes shared by any two thoroughbreds had risen from 31 per cent two centuries ago to around 47 per cent now."

Sounds scary in isolation.
Now compare it to other breeds of horses and you might be in for a surprise.
Compare it other domestic breeds of animals, like some of the ones you eat and pet, and you could get really surprised.

[grayarabpony]

Obviously if you are going to breed father to daughter or mother to son you want to start with the best individual you can find. You do not want to double up on any obvious flaws. Does the stallion have a weak croup? If so, and you breed him back to his own daughter, chances are the resulting foal will have a croup that is much, much worse than the sire's.

Line breeding (or inbreeding) brings out the recessive genes. If there is a recessive gene hiding in a stallion, if you breed him back to one of his daughters chances are that recessive gene will show up in the foal. This is why if one is going to practice inbreeding or line breeding, one must be prepared to cull. One should always be prepared to cull, but it's even more important in linebreeding/inbreeding.



Shaking head. This post explains exactly why I think linebreeding is to be avoided. What happens to all these culls? and there are likely to be more/ worse culls than in regular breeding, because traits are concentrated. Undesirable traits do not always show up before the offspring has already reproduced, either. Look at the problems with Impressive's get.

The American TB does need an infusion of fresh blood. I cannot imagine the books being opened any time in the next 100 years, but at least a major sire from another continent. DH read an article in the Blood Horse or a similar racing magazine advocating this a couple of years ago.

As far as cattle being inbred, and more productive -- they are also more productive because of the feed, medicines and practices that are currently followed. They are also dumb as dirt and don't live long anyway, because they are always slaughtered before they are even middle-aged. Dairy and beef cattle are not embodiments of qualities I would look for in a sports horse.

[Annetta]

Oh please. Like there are no culls--or what should be culls--in outcross breeding? Come on. Someone comes on here & asks what should they breed their Morgan/QH/pony mare to...and Arab/Percheron or a TB/Belgian...and they get blasted big time because mixed breeding is such a bad thing. Actually that mixed breeding is about as outcrossed as you can get, so if outcrossing is such a good thing...mixed breeding should be a good thing.

There are--or should be--culls in every breeding program. And I maintain that if a breeder studies his horses, their pedigrees, and is perfectly honest about their conformation and especially about their conformation faults, he can make a pretty good judgment as to whether or not he should attempt a certain cross of inbreeding/linebreeding--and there's a very high probability that the cross will be a success and not a cull. And from there, if he uses that inbred horse to breed his mares, he knows what that sire is going to produce, yes, time after time, because those traits are "set" in that horse. Once you are at that point you actually reduce the number of culls in your foals, because you have consistancy...consistantly good quality foals.

Too many inbred crosses will reduce vigor and perhaps longevity--I agree that repeatedly breeding inbred to inbred is not a good thing to do, but breeding the right stallion to his own daughters can make for a very strong line.

[grayarabpony]

Culls in a regular, well-thought-out cross usually means a horse that is going for something besides that discipline. Culls from inbreeding is likely to be something worse.

What do you think the premier sporthorses in English riding (warmbloods) are if not outcrosses? The same with German Riding Ponies. After WWII the warmblood numbers were so low that they had to outcross, which resulted in the modern warmbloods that dominate dressage, eventing, showjumping, and driving today.

[hluing]

Fascinating conversations! Outcrossing vs linebreeding...I think both have there place in a well thought out breeding program...and I agree if you linebreed fairly closely...you are wise to outcross after that. It is interesting that someone brought up my breed, the German Riding Pony as an example of an outcross. While this is true...there is aslo a good bit of linebreeding in the breed. I have two full sibs that are linebred to two greats in GRP breeding: Black Boy and Constantin. While I think they are both very nice individuals...when I breed them in the next 1-2 years it will be to ponies with none of that blood. However, I do think that I will have a better idea of what stallions to choose based on their linebreeding.

My summary of this: When linebreeding...use moderation and only use it to concentrate the BEST bloodlines. Follow by outcrossing. For outcrossing...keep in mind breeding like to like at least somewhat and be very sure of your breeding goal and the ancestry of what you are crossing.

No wonder we are all hooked on breeding!

[tri]

"which resulted in the modern warmbloods that dominate dressage, eventing, showjumping, and driving today."

Surely you aren't suggesting that they are successful because of hybrid vigor are you????? They are successful because so many mares were LINEBRED to concentrate the genes that produce push from behind, elasticity, well set on necks and power. Have you even studied some of the most famous and sought after lines used in europe???? They are LINEBRED!

[florida foxhunter]

When I started my breeding program I did a lot of research. Dr. Michelle LaBlonc (now KY) was then at the U of FL....I asked her about line breeding (in a phone call.......nothing in writing),. She said a 2X3 was as close as she'd recommend.........but she was comfortable with it as long as it was good quality horses..and well thought out....

[Annetta]

Culls in a regular, well-thought-out cross usually means a horse that is going for something besides that discipline. Culls from inbreeding is likely to be something worse.
Not necessarily. In terms of a Morgan breeding program where sire is bred to daughter...assuming that I started with a stallion of the quality I would require for such a breeding program...if the resulting offspring turned out to be a cull I wouldn't expect it to be terrible, deformed, weak, sickly foal--my idea of a cull would be a foal that turned out to be a little less spectacular than I expected, not exactly of the type I'd want to have stamped on his (or her) future foals--but it would still make a good using horse. It might even make a show horse, just not a breeding animal for my program. That would be my cull. Given my knowledge of the breed and which traits each line or family is known to produce it would be unlikely that I would get a terrible freak from any inbreeding I choose to do. Would I go out & attempt to do the same sort of breeding with a different breed, say Welsh ponies? No, because I don't know enough about Welsh ponies to be able to determine which lines have proven to produce which traits.

The biggest danger in this sort of breeding is when people do it indiscriminately. They don't know which traits they're likely to get from a certain cross. They don't even see the faults in their breeding animals, so can't see that a certain father/daughter cross is going to double up on some rather serious fault. There is just no room for barn blindness in this sort of breeding program. You have to know when not to use a certain horse for linebreeding or inbreeding, you have to know when to stop linebreeding and go to a good outcross.

[Kate66]

We do it with our cattle (who are nice, registered). We would breed a mother to son, but would not breed a resulting heifer to her father - that is too close.

[grayarabpony]

Surely you aren't suggesting that they are successful because of hybrid vigor are you????? They are successful because so many mares were LINEBRED to concentrate the genes that produce push from behind, elasticity, well set on necks and power. Have you even studied some of the most famous and sought after lines used in europe???? They are LINEBRED!

The top show jumpers I am familiar with have no inbreeding for the first 4 generations and hardly any in the first 8: Cruising, Lando, Baloubet de Rouet, Calvaro V, ET, Ratina Z, The Natural, Tinka's Boy, Rochet M, Fein Cera, Liscalgot, For Pleasure, Jus de Pomme.... The sire of my own horse, an imported Hanoverian, does not have much inbreeding either. I'm not very familiar with dressage lines but the same applies to Brentina and Rembrandt.

[pwynnnorman]

Well, I hope the "what do you do with the culls" question has been put to rest. That comment made it seem like inbreeding results in dim-witted, seven-gaited, up-the-mountain-backwards types. Usually, it just results in some conformational flaw that disqualifies the animal for showing or further breeding...and that's the end of it, thankfully.

The problem is when it results in some great-looking something (inbred or not) that never actually proves its ability to do something other than look good is then used for more breeding. Since performance is never tested (or--the dilemma we face in this country--performance is poorly or inaccuately "tested"), guess what happens to that trait? I tend to think that the unsoundness and/or unsuitableness of breeding for phenotype without performance results linked to genotype results in far more sad, discarded horses than well-reasoned inbreeding.

Indeed, I like to think that those who inbreed wisely, do it NOT for more of anything, except consistency. Not to INCREASE traits (that would be, I think--it's the only thing I CAN think of--why one would go back over and over to the same gene pool, yes?), but rather to solidify them, make them occur more consistently and predictably specifically so that when you then outcross, you don't lose what your program has gained. It IS so very true that outcrossing two individuals can be a humongous crapshoot. HUMONGOUS. Meanwhile, getting a program to a point where it can produce that consistency without inbreeding (or linebreeding) can take a very long time--if ever. Inbreeding can be a sensible short-cut to consistency for the serious breeder. Being able to claim and prove prepotence should have value (alas, ignorance often negates that when the public gets involved, but done privately, the value can't be denied).

[Caveat: Of course, many a stallion owner makes claims that their crossbred (lines and/or breeds) stallion is "prepotent," but keep in mind that most stallions in this country do not have many get and those get are not tracked, so at best "prepotent" means phenotype, not genotype, and also mostly means that the babies seem to look and move similarly. And we all know how that can change over time, so "prepotent" claims, especially in a stallion produced by outcrossing pheno- or genotypically differing lines: dressage lines to jumper ones, I would presume...or racing to dressage (like many WB breeders using TB mares). Again, it's worth remembering that few breeders here can really support claims of prepotency in the show ring. One group that is the exception here, because of the nature of their sport, are indeed pony hunters which have a much quicker turnaround in proving blood.]

I was just watching the DVD of Badminton 2007 in which Headly Britania--small, scrappy, hyper-hot, fast, very TB-like--won while another Jumbo offpspring--huge, slow, deliberate, WB-like Harry Mandeville--also placed very well. As a mare owner, wouldn't you prefer to know which type you were more likely (no, not guarenteed, obviously: the mare does have something to do with it!) to get?

IMO, the saavy mare owner would find the successfully-inbred-to-well-proven-greatness (like Farnley Lustre boys) stallion HUGELY attractive to breed an outcross to, especially if the mare had faults or weaknesses that needed strengthening.

[Dazednconfused]

And a better indictment of incessant linebreeding I’m not sure I’ve read. Thank you for that link. There are unintended consequences for everything we do in life. And it’s VERY clear Mother Nature does not like too much of a good thing.

And yet, in a previous post you say “ Line breeding with Impressive certainly produced the type that is sought after for Halter classes. So from that point of view linebreeding certainly worked. The bad part was that it brought along a genetic disease. If HYPP hadn't come along for the ride I'm not so sure anybody would be complaining about line breeding in QH's.“

So you think that HERDA is a one-off? Just a cosmic fluke? If you are tired of exploring QH genetic diseases we can move on to Arabian or Mountain Curley’s if you’d like….

I’m keeping quiet about HYPP, as the prevalent thought now is that it is the result of breeding for a certain trait (precocious muscle mass), not the result of inbreeding per se. Though I have my doubts, I’m bowing to the geneticists on this subject.

As far as I am aware, the genetic diseases I am familiar with in arabians have nothing to do with inbreeding, as there is no one source horse (with SCID, there are many suspected sources and they are all from the desert - not like with say, Quarter Horses, where we know that HYPP came from Impressive and not any other line).

[eqsiu]

TBs are descended from 3 stallions and 25 mares. How is that not highly inbred?

http://www.newscientist.com/article/dn7941.html



When the common ancestors are 20+ generations back, how does one calculate the inbreeding coefficient?

[pwynnnorman]

TBs are descended from 3 stallions and 25 mares. How is that not highly inbred?

http://www.newscientist.com/article/dn7941.html

I forgot about that comment and that I had wanted to respond to it, too.

Because it's a bit of bull--idealistic bull, that is. :D [Edited to add: one must always view science with a critical eye, realizing that those who report on it rarely take the time to report methodological weaknesses such as the built-in inaccuracies of a written record, like a stud book. They also don't report standard deviations and, in this case, use terms like "the majority," which is not a scientific term at all and thus renders much of what they concluded rather meaningless as written.]

Until there was DNA testing, there were almost certainly few if any breeds that were pure, TBs included. Three stallions, 25 mares and a whole heck of a lot of who-knows-what is what is in all TB genes until well into the 20th century. If it weren't, there'd be no colored TBs and/or there'd be a lot more FAST ones (colored TBs that is).

[grayarabpony]

Well, I hope the "what do you do with the culls" question has been put to rest. That comment made it seem like inbreeding results in dim-witted, seven-gaited, up-the-mountain-backwards types. Usually, it just results in some conformational flaw that disqualifies the animal for showing or further breeding...and that's the end of it, thankfully.



Who says? :confused:

Usually smart breeders try to breed horses with similar builds so as to not get mismatched parts. If you breed an athlete to an athlete you're likely to get an athlete -- no inbreeding required. And a more flexible individual who can exceed at more than one discipline, which is always an advantage.

[stolensilver]

pwynnnorman the number of foundation horses in the TB breed is largely based on the number of different types of mitochondrial DNA which (as I'm sure you know) only comes from the mare. With a starting base of 28 horses and no outside blood the TB gene pool IS very small and getting smaller. That was what the other figure represented; that TBs share almost 50% of their genetic material.

Talking about warmbloods someone mentioned the worry about mixing dressage and jumper blood. I don't see this distinction. How a stallion is labelled depends on how it is marketed. Some of the big name dressage stallions are 100% jumper blood. For example Sandro Hit and Flemmingh. There are many more.

I've just looked at the inbreeding in the following dressage horses (since someone has kindly done showjumpers) I picked them from the FEI international results lists.
Sandro Hit: no inbreeding for 4 generations.
Don Schufro: no inbreeding for 4 generations.
Donnerhall: no inbreeding for 4 generations.
Ollright: no inbreeding for 4 generations.
Krack C: has Lorenz twice in the 4th generation.
Relevant: no inbreeding for 4 generations.
Rubinstein: no inbreeding for 4 generations.
Ferro: no inbreeding for 4 generations.
Weltmeyer: no inbreeding for 4 generations.
Gribaldi: has Ibikus twice in 4 generations.

I haven't carefully selected these horses to prove my point. I've just gone down an FEI list of horses who have done well at international GP and thrown in a couple of big name stallions that came to mind. From the list above of successful dressage horses and the previous one of successful showjumping horses I'd say that there isn't any evidence that inbreeding produces outstanding individuals! There aren't any in either of those lists.

[eqsiu]

TBs share almost 50% of their genetic material.



Given that the genomes of humans and chimps are 96% the same, I bet that TBs share more than 50% of their DNA.

Edited to add: The study mentioned previously used a sample size of 211 thoroughbreds. Given that the Jockey Club registers ~37,000 horses each year in North America (they show about 430,000 names in active use), how can that truly be a representative sample of all thoroughbreds worldwide?

[stolensilver]

eqsiu there is a difference in humans and chimps "sharing" genetic information and the info about TBs. A gene can have several different expressions of the same gene, sort of like different letters of the alphabet. That is what is being talked about when comparing humans and chimps. With TBs what they are saying is that the gene at locus 1 is identical in almost half the population. So using the alphabet analogy almost 50% of TBs have gene A at locus 1. This is a simplification but I hope it makes sense.

Inbreeding scares me! It has done a lot of harm to dogs and we seem to be going down the same road with horses. The evidence from performance tested horses is that inbreeding does not produce world class athletes. Outbreeding does.

[PineTreeFarm]

pwynnnorman the number of foundation horses in the TB breed is largely based on the number of different types of mitochondrial DNA which (as I'm sure you know) only comes from the mare. With a starting base of 28 horses and no outside blood the TB gene pool IS very small and getting smaller. That was what the other figure represented; that TBs share almost 50% of their genetic material.


I'm not convinced that there are only 28 horses for the starting base. Lots of stallions used in the early TB have no male survivors today but their blood appears in the female lines.

http://www.pedigreequery.com/brown+farewell
Brown farewell can be traced forward to modern times. Her pedigree does not contain any of the 3 foundation sires.
Golden Grove...Pucelle.. Barbara Burrini brings her bloodline forward to modern times.

I've lost track of the family numbers but there are English, American, Colonial, Half Bred and Others ( Polish etc. ) Lots more than 20 something mares.
And the practice of naming mares after the owner makes it impossible to find out who some of these mares really were.

TB Bloodlines has a lot of this info. I'll try and find the link.

[Fairview Horse Center]

I think if you look at many of the Hanoverians, they are line bred. I have found Absatz used 3 and 4 times in MANY pedigrees. Idocus is not only very sucessful as an Olympic Dressage horse, his offspring are also having outstanding success in many disciplines. He is double Furioso.

I have selectively line bred (2/3), and they have been my best youngsters, but I did not do it to solidify the genes. I did it because the stallion and dam were outstanding crosses on each other for conformation and gaits. I did it inspite of the linebreeding, after making sure that the doubled horse was VERY solid with no "holes".

I do worry at the trouble we are getting into though. Soon we will all be breeding Sandrodonnerrubinmeyers to Welthallhitsteins.

[pwynnnorman]

Yeah, on the TB genome--you just can't pretend that everyone who bred them over the years always used the horses they stated they used. You just can't. And since you can't, there's a problem with the data (or something that needs to be explained that couldn't be in the space allowed for the article). Outcrossing had to have existed. Humans just ain't that honest, collectively! [But I'll admit I may be missing a point someone is making due to not quite understanding the percentage and mare thing...]

Next, while it is interesting that there's no inbreeding in the WB's listed, it would be more interesting to go back beyond four generations as well. Remember, it's used to set type. Why continue inbreeding if the type is there? After you have type, you proceed to outcross to IMPROVE type--like inserting TB blood, for example.

Also remember that the world is comprised of more than just WBs and that, again, you will find inbreeding in others. Just because it isn't done over there doesn't mean it wasn't done over here or there or there...Indeed, the folks who have used it successfully weren't idiots, people. Over time and generations, they wisely improved their stock, as is done with many, many species. Let's be realistic, after all.

And, grayarabpony, I think it is somewhat naive to state: "If you breed an athlete to an athlete you're likely to get an athlete -- no inbreeding required. And a more flexible individual who can exceed at more than one discipline, which is always an advantage."

Would that it were that simple. How long have you been in the breeding business?

I am truly curious as to why folks choose to deny the very history of a concept (and contemporary examples and experiences) in favor of arguing on the basis of little more than personal supposition (I am not including the WB in that--I found the data reported on those 4 generations intriguing in light of this debate). Do you really think all the highly respected breeders who done did the deed were idiots or somethin'? Do you think there is nothing to be learned from their experiences?

[eqsiu]

eqsiu there is a difference in humans and chimps "sharing" genetic information and the info about TBs. A gene can have several different expressions of the same gene, sort of like different letters of the alphabet. That is what is being talked about when comparing humans and chimps. With TBs what they are saying is that the gene at locus 1 is identical in almost half the population. So using the alphabet analogy almost 50% of TBs have gene A at locus 1. This is a simplification but I hope it makes sense.

Inbreeding scares me! It has done a lot of harm to dogs and we seem to be going down the same road with horses. The evidence from performance tested horses is that inbreeding does not produce world class athletes. Outbreeding does.

No, it means that 96% of the genes (read: alleles) are the same in humans and in chimps. You're saying that half of all TBs have a particular allele of a specific gene. Well duh. Which one? Are we coding for the same DNA polymerase, or are we talking about same color? There are vast numbers of genes that are required in order to produce a viable organism, and they are highly conserved across species.

And I still say that you need a multinational sample much larger than 211 horses to prove that TBs all came from the same ~30 individuals. It sounds like you think that if one traces a pedigree back far enough that there will only be 28 mares and 3 stallions repeated over and over, and that just isn't the case. Yes, the 3 foundation sires are found in all TB pedigrees, and I'm sure that those 28 mares (or marelines, as is the case with mitochondrial DNA) are in them all too. However, that does not mean that those are the only ancestors in the population. And once again, if the common ancestors are 20 generations back, who gives a damn?

I don't like inbreeding closer than 4 generations. It's easy enough to produce the horse you want without further inbreeding. Yet inbreeding does not create faults in a population, it simply magnifies the effects. Those recessive alleles are there whether you inbreed or outcross.

Interesting factoid: I have yet to see a warmblood that didn't have a TB in there somewhere, so I guess that means that all warmbloods are descended from those 31 horses too. So my Hann/TB cross is highly inbred!

[pwynnnorman]

I think if you look at many of the Hanoverians, they are line bred. ...I do worry at the trouble we are getting into though. Soon we will all be breeding Sandrodonnerrubinmeyers to Welthallhitsteins.

:lol::lol:

But on a more serious vein, I was genuinely curious about what was pointed out, so I did a quickie search and found this interesting statements on a website describing the history of the Hanoverian:

"In the 130-odd years of its existence as a breed in its own right, the Hanoverian half-bred - known since 1921 as a "warmblood" - has never been a closed shop. Over this period, breeders have never adhered fixedly to one set aim. In fact they have always tried to avoid uniformity within the breed. Once a sufficiently broad female foundation had been achieved, the breed authorities endeavoured, with the help of Thoroughbred, Trakehner and Arab blood, to match their products to the market demands of each period, i.e. to produce a light or heavy farm-cum-military horse in the early decades of the century, then an all-round competition and leisure horse for the present day market." http://www.horsemagazine.com/BREEDINGBARN/BREED_SOCIETIES/HANOVERIAN_SOCIETY/history.htm

Could this be the reason (or maybe the philosophy) which explains the no "inbreeding in four-generations" finding...in contrast to other breeds and/or types? Is it that "uniformity" has been the goal for many breeds, but NOT for the WB, which, after all, isn't really a breed? (I'm asking, not arguing here.)

Oh, and in the process of researching this, I found this interesting statement about Standardbreds: "Through selective inbreeding, the male line of every standarbred stallion that has sired as many as five performers in the two minutes or faster record category has a direct male line to Hambletonian." http://www.thehorses.com/standard.html

And here's another interesting finding, this one about the Irish Draught:
"It is interesting to note that the overall level of inbreeding in the Irish herd has jumped significantly in the years since 1991, when performance testing of stallions was instituted. The ICBF data is viewed by many as confirmation of something long suspected—there is decreasing genetic diversity in the Irish Draught herd and it is likely that a significant factor in this trend is stallion selection." http://www.theirishhorse.com/publications.html

But perhaps the most interesting thing I found was that every time I plugged a breed name in a search with the term "inbreeding," some interesting stuff came up!

[pwynnnorman]

I know, I know--I'm like a dog with a bone. But I have to go and work some horses now, so this is the last! (Truth is, I happen to enjoy finding stuff out--research for research's sake.)

Check out this interesting analysis [http://www.tbheritage.com/HistoricSires/JumpSires/JumpWEG2006.html] of the 2006 WEG Bloodlines (but do note, I think the author isn't using the term "inbreeding" the way we have):

In contrast, Cumano's pedigree is as typically top quality Holsteiner as is imaginable, with his sire Cassini I by Capitol I and his dam Chanel II by Landgraf I, and 3 x 3 inbreeding to Cor de la Bryère's son Caletto II, with further linebreeding to Cottage Son (javascript:psShowWin('jump', 1, 'JSimag/cottageson.html');), Ramzes and the thoroughbred Marlon (javascript:psShowWin('jump', 1, 'JSimag/marlon.html');). Interestingly, while there is only one thoroughbred ancestor in the first three removes of Cumano's pedigree, in the sixth remove 45% of his ancestry is thoroughbred.

Cassini I also sired the team Gold medal winner Berlin (out of Estia, by Caretino), who is also inbred 3 x 3 to Caletto II and linebred to Cottage Son and Ramzes. Curtis (by Coriano out of Zalouba, by Aloube Z), another team Gold medal winner, is inbred 3 x 4 to Capitol I, and in addition to the typically Holsteiner ancestors Cor de la Bryère and Ladykiller (javascript:psShowWin('jump', 1, 'JSimag/ladykiller.html');) also descends from Almé. Capitol I is the grandsire of team Bronze medalist Cöster (by Calato Z out of Dispache, by Constant), who is linebred to Cor de la Bryère and to Cottage Son. The Holstein influence is also strong in the pedigree of team Bronze medalist Küchengirl (by Lord Z out of Classics, by Cambridge Cole), who was bred in Bavaria from a grandson of Ladykiller, but whose dam was by a Dutch Hackney.

The Dutch warmblood Miss Independent (by Kingston out of Jakretia, by Nimmerdor), winner of a team Silver medal, is inbred 4 x 3 to the Holsteiner Farn, and descends in the male line from the Trakehner Marco Polo, the reputed grandsire of Milton. Miss Independent also descends in the 3rd remove from Ramiro, who also is the grandsire of team Gold medal winner Oki Doki (by Jodokus out of Kentucky, by Topas), who is inbred 4 x 4 Farn and who also descends from Marco Polo.

The Belgian Warmblood team Gold medalist Up And Down (by Ohio van de Padenborre out of Pin Chin, by Chin Chin) has a Selle Français sire and granddam, while his maternal Holsteiner grandsire descends from the Selle Français Cor de la Bryère. Therefore, 5 x 4 x 4 inbreeding to Ibrahim is not surprising. 3 x 3 inbreeding to the Selle Français mare Draisenne, by Noe TB, appears to be a specific experiment of Up And Down's breeders, which seems to work based on the stallion's performance. The team Silver medal winner Quervo Gold (by Jus de Pomme out of Nura, by Codexco) also has strong French influences, since his Olympic Gold medal winning sire, although registered in Belgium, was bred on Selle Français lines, while Quervo Gold's maternal grandsire had a Selle Français dam, resulting in 5 x 6 x 5 linebreeding to Furioso (javascript:psShowWin('jump', 1, 'JSimag/furioso.html');) and further linebreeding to Ibrahim and Ultimate (http://www.tbheritage.com/HistoricSires/JumpSires/JumpShowroots.html#ultimate). The other Belgian-bred team Silver medal winner Sapphire (by Darco out of Idjaz-c, by Hedjaz) is a mixture of Hanoverian, Holsteiner and French blood.

[tri]

Here is a bunch more - greyarabpony just isn't looking:

Canvado Z Cor de la bryere both top and bottom
Amour Alme Z both top and bottom
Ariadus from Fox Fire Farm is out of a line bred Ladykiller mare
Caballo is out of a line bred Ramiro mare with more Ramiro on top
Cabardino has Ladykiller both top and bottom
Cacique has Cord de la Bryere top and bottom
Camiros has Ramiro both top and bottom
Carpaccio is out of a line bred Ladykiller mare
Cascani has Cord de la Bryere top and bottom
C.D. has Cord de la bryere top & bottom AND Ramiro top and bottom
Chaleon – the up and coming hunter - has Caletto I top and bottom
Chosen has Cord de la bryere top and bottom & Ladykiller top and bottom
Indoctro is out of a line bred Cor de la bryere mare
Cicera’s Icewater has Cor de la byere top and bottom
Cisco has Cor de la bryere top and bottom
Con Caletto has Cor de la bryere top and bottom
Flemmingh has Ladykiller top and bottom
Linaro has Ladykiller top and bottom and then sired Lintas who also has Ladykiller in his line
Lordship has Cor de la bryere top and bottom
Luganda has Ladykiller top and bottom
Riverman from Hilltop Farm is linebred Landgraf
Rasputin is linebred Ramzes
Secret Agent is out of a linebred Gotthard mare

That is all from just one website and there is soooooo much more.

[lauriep]

Responding to the comment back on page two about dog breeders/breeding having produced so many problems:

It is not fault of the breeding mechanism. It is the fault of the breeders who narrowly focused their breeding on a physical look that they wanted to cement, regardless of what underlying ailments came along. If they had been honest in acknowledging these problems when they appeared, and subsequently eliminating these individuals from any breeding program no matter HOW beautiful they were, the problems could have been reduced or eliminated in a few generations. However, they did not do this, and so you have all of the life shortening genetic diseases/ailments that purebred dogs are known for.

HOWEVER, when inbreeding has been applied knowledgeably and with complete honesty about the results, it has produced individuals and lines who breed true to type and are healthy and vigorous. But any amount of kennel/barn blindness will defeat this valuable tool. THAT is the problem with so many breeders of horses and dogs. If you were to always breed using outcrosses, it would be impossible to fix any of the positive traits that you are looking for, as you would never be able to double up on them, except perhaps by accident. A stallion or dog that breeds "true" has always been a hugely valuable commodity because they could reliably produce a look/temperament/etc. no matter what they were bred to. And when you, the mare/bitch owner, look for a sire to solve problems with your animal, you will be far more successful breeding to an individual who has proven, over and over, that he possesses and passes on the things you are looking for. And that just can't come from an outcross.

[stolensilver]

Tri I've looked at the pedigrees of most of the horses you've posted and of those I've seen at most they have one ancestor twice in 4 generations. That isn't inbreeding as we've been discussing like father to daughter, brother to sister, Raffles type inbreeding. I think again we are seeing that the top performing equine athletes are not heavily in bred.

[Fairview Horse Center]

Tri I've looked at the pedigrees of most of the horses you've posted and of those I've seen at most they have one ancestor twice in 4 generations. That isn't inbreeding as we've been discussing like father to daughter, brother to sister, Raffles type inbreeding. I think again we are seeing that the top performing equine athletes are not heavily in bred.

I thought we were discussing within 4 generations and as one poster requested, even further back. :confused:

[VolteVT]

Posting as one of the researchers on the original TB stud(ies) mentioned, and as the one who sorted through and analyzed the Weatherby's stud book database, I just wanted to clarify a few things...

The 211 horses were ones on which we also had microsatellite information to compare to the pedigree data (we were investigating our ability to determine pedigree relationship through molecular methods). Pedigree analysis of the GSB was done with many many more horses (over 1 million horses dating from 1650 through 1998 if memory serves). I killed at least two computers on this project trying to invert a relationship matrix...

The foundation of the breed had many more than 3 sires and 25 dams - those numbers came from sireline/damline founders (i.e., foundation sires still found in sirelines today, the same for female families/taproot mares) present in the population studied. Actually, there were more than that (e.g., Lady Blunt's/Wentworth's horses still can be found in an occasional GSB sireline) but those were the sire/dam line founders with major contributions dating pre-1780 or so.

As a side note, pedigree information is only as good as those recording it. When we looked at female families vs. mitochondrial DNA (passed along the maternal line) we found an error rate of almost half! (Happy to elaborate via PM if anybody wants to chat about it, but don't want to go too far OT) I was also surprised to learn there are over a dozen ways to spell "Man O'War" (combinations of spaces, apostrophes or lack thereof) and each was considered a different horse in the Weatherby's database before I started screening it.

Inbreeding is also relative to what you are considering as your base generation. I don't consider myself inbred, but if I go back far enough in human history, my parents are certainly somehow related, which would make me, by definition, inbred.

Inbreeding and outcrossing are among the most powerful tools available to any breeder.

[eqsiu]

VolteVT, that makes much more sense.

And hopefully you aren't as inbred as Charles II of Spain. http://en.wikipedia.org/wiki/Image:Carlos_segundo80.png :)

[stolensilver]

This is a really great discussion. Different views, lots of information and no nastiness. Fantastic!

[Drvmb1ggl3]

VolteVT, that makes much more sense.

And hopefully you aren't as inbred as Charles II of Spain. http://en.wikipedia.org/wiki/Image:Carlos_segundo80.png :)

Here's what that looks like as a horse pedigree... http://www.allbreedpedigree.com/charles+ii+of+spain

Makes my head hurt. If you could see it as a 6 or 7 generation pedigree, it would look even weirder.

[tri]

I am my own grandpa. :)

"I thought we were discussing within 4 generations and as one poster requested, even further back"

So did I. Also doesn't change the fact that some of the ones listed were out of linebred mares and that some had 3 crosses to the same blood.

[grayarabs]

I have often wondered if inbreeding was the trigger for SCIDS in Arabians. Was there an index horse ie did it start with just one horse that was perhaps inbred or did it just "pop up" out of nowhere in several horses? And when? where? Only recently or has been in the breed for much longer than we ever thought? It would be interesting to input data into a computer with the known positives and see if they trace back to one horse (like Impressive for QH's).
www.foal.org has a list of some carriers but what could one learn from those horses?
Also interesting on allbreedpedigree the horse DP Black Minx is listed as SCID positive - dunno who put that info there. Arabian stallion ads now mention if they are SCID clear - but I have never seen a published list of positive horses - which would be very interesting to research. Is there such a site? Arabians all came from the desert but then were dispersed to different countries - then SCIDS appears. Thoughts? Inbreeding or what other possibilities? A friend of mine had a SCID positive stallion - only discovered after a positive foal - the stallion had a very famous sire or grandsire - don't remember - but one could not point to that famous stallion as other lines mixed in - very confusing. Friend did the right thing - did not hide the fact and had the horse gelded. SCIDS has always puzzled me.

[stolensilver]

IMHO SCIDS is a poster child for being a disease that has surfaced due to inbreeding. It is recessive so you need two copies of the same gene for it to affect a horse (foal). Arabs are very highly inbred. If you breed close enough for long enough it is a mathematical certainty that two apparently healthy individuals carrying the same recessive defective gene will reproduce and each pass on the fault. It is only when an individual has a double dose of the faulty gene that it is expressed so with recessive diseases in is usual for both parents to be completely healthy. Since SCIDS seems to be widespread throughout the Arab breed the original mutation probably happened a long time ago or occurred in one very well used stallion like Poco Bueno in the Quarter Horses.

Interestingly it has been estimated that the average healthy human being carries three recessive diseases (3 defective recessive genes). If they have kids with someone completely unrelated to them it won't matter as that person is unlikely to carry the same 3 defective genes. If they have kids with someone closely related then such as a cousin or that horrifying family tree for Charles II of Spain the risk of both parents having the same recessive gene and both passing it on to their offspring is much greater. All of the inbred populations of the world have a high incidence of recessive genetic diseases. Tay-Sachs, Haemophilia (X linked but still genetic), phenylketonuria and many many more. These populations also have a lower birth rate than average because many recessive diseases interfere with implantation of the fertilized ovum in the uterus and all of the other essential steps needed to get from fertilization to birth. Often very early miscarriages are not noticed and all that is seen is sub-fertility.

I am sure that horses also carry a number of mutated recessive genes. Inbreed them often enough and the offspring will get a double dose of the defect. So I have no doubt in my mind that SCID foals are being born because Arabs have been inbred.

[Astraled]

One short story helps to put SCID in perspective. Visitors to the United States in the late 1970s from a Middle East Arab-breeding country were told of the devastation of producing a SCID foal. The visitor response: "Oh, we've known about that condition in Arabian horses for centuries. We just call it 'Allah's curse' and get on with breeding."

From VetGen's website (http://www.vetgen.com/equine-ref-CIDAnUpdate.html)

SCIDS can be found in any Arabian of any breeding, so the original source must be quite far back.

[grayarabs]

This may be only of interest to Arabian breeders or the scientific type - but I found the most interesting discussion on SCIDs and inbreeding - if the long URL works:
http://forums.ablackhorse.com/lofiversion/index.php?t6484-100.html
(four pages - start with page one)

or go to www.ablackhorse.com
forums
CMK and Crabbet
Search for discussion on stallion The Real McCoy from March 2006

Folks there with much info - and yes TRM implicated as positive - others mentioned - theories about the desert horses ie Berk - and one mare indicated as possible index case - but name not given. Fascinating reading.

(previewing post - noted URL not intact - should read: after com/

lofiversion/index.php?t6484-100.html

(why does this happen?)

[Astraled]

My guess is that the mare mentioned is Rodania. None of it matters these days, of course, as there is a test so there's no chance a responsible breeder would get a SCID foal.

[Dazednconfused]

;)IMHO SCIDS is a poster child for being a disease that has surfaced due to inbreeding. It is recessive so you need two copies of the same gene for it to affect a horse (foal). Arabs are very highly inbred. If you breed close enough for long enough it is a mathematical certainty that two apparently healthy individuals carrying the same recessive defective gene will reproduce and each pass on the fault. It is only when an individual has a double dose of the faulty gene that it is expressed so with recessive diseases in is usual for both parents to be completely healthy. Since SCIDS seems to be widespread throughout the Arab breed the original mutation probably happened a long time ago or occurred in one very well used stallion like Poco Bueno in the Quarter Horses.

I am sure that horses also carry a number of mutated recessive genes. Inbreed them often enough and the offspring will get a double dose of the defect. So I have no doubt in my mind that SCID foals are being born because Arabs have been inbred.

This makes no sense whatsoever. There is no one source horse for SCIDs. Arabians are not highly inbred as a breed. There are many people that breed arabians that practice linebreeding and inbreeding - but as a breed? Not really.

What is your source that it "one very well used stallion"?? I would be very interested to read it.

There are many, many foals that were SCID affected that were born that had no inbreeding at all. So really, this post makes very little sense.

[pwynnnorman]

grayarab, I got as far as The Crabbet and CMK Breeders Forum, but couldn't figure out how to search it. Can you tell me how? Thanks.

[stolensilver]

Dazednconfused recessive diseases only surface if the gene pool is small or you are extremely unlucky. If bad luck is involved one breed would not get the same recessive disease occurring over and over. Each occurrence of a recessive disease would be a different disease. For SCIDS to recur in Arabs points very strongly to the gene pool in Arabs being small. What on earth do you base your statement "Arabians are not highly inbred" on? They have been inbred for centuries!

There are some fascinating posts about Arabs and SCIDS on here. Sounds like the gene has been around for a long time.

[grayarabs]

P - I know - is tricky. try it this way since my URL is wonky for some reason missing things.
I just tried this and it came up - do google search engine:

ablackhorse.com real mccoy
it pulls up page four - but start obviously at page one.

I think that will pull it up. I think other discussions regarding scids that forum which I will research. so far I have found many answers.

For some reason all these years I thought that SCIDs a more recent event - like AIDS.
Now it appears has been around for centuries - starting in the desert.

All this to me very thought provoking in many ways. Until reading this I thought that all SCID carriers etc should be out of the breeding pool. ie stay away from the SCID positive stallions regardless if you have a negative mare. Then I got to thinking - I'll bet in the Arabs I have owned that there were SCID carriers/positives in their pedigrees. Probably some really nice horses. If we were to take out of breeding programs all the SCID positive horses - would that not then narrow the pool of horses and ultimately cause more inbreeding? Thinking about this...... I don't breed - never have. The Arabs I prefer are the sport type - not the halter horses etc one sees in the magazines AHW etc. I like the old style Arabians - not the new fad of the week. I would not breed to "new fad SCID positive" but might to a fabulous old style positive with appropriate mare. Can you imagine if Meseoud for example was known to be positive and gelded? Raffles? Much to think about - and yes - there is the test now - thank goodness. FWIW my late Arabian (rescue) horse Halima Two - his sire and dam by A. Ibn Halima - my guy looked exactly like him - and was the most perfect little horse - even as a stallion. I lost him at age 28 to Cushings/laminitis - but until that time he was the picture of health in all ways and was a wonderful little dressage horse/dream to ride.

[Rebecca Anderson]

Since it appears that this discussion is winding down I would like to say thanks to all the people who have shared their opinions, knowledge and experience. It has really been a fascinating discussion! I will be keeping an eye on that colt in the future and I have a mare that I would be seriously interested in using him on at some point. And yes, she is a complete outcrosss.