A Fool Rushes In: On Inbreeding
I wanted to highlight an interesting conversation on inbreeding taking place in the comments on Javera Chelsea’s photos. I hope this exchange will serve as a teaser:
Lyman Doyle wrote:
[…] Inbreeding is certainly a fascinating and very complex topic.
Googling “inbreeding” can turn up a lot of different information. Granted, you can’t believe everything you read on the internet, but some of it appears to be fairly well reasoned. […]
I think there are several points of significance:
1. Inbreeding does create some degree of uniformity. The main genetic result of inbreeding is to increase the occurrence of the coupling of like genes.
2. Inbreeding does bring out those genes that are recessive including those that may be harmful to animals that are inbred.
3. Inbreeding is useful in uncovering otherwise harmful or undesirable characteristics and purging these characteristics from the genetic population.
4. Inbreeding is important in the development of animals that are “potent” with certain more favored characteristics that manifest in their offspring.
R.J. Cadranell wrote:
Lyman, regarding your point #1, inbreeding by itself does not create uniformity. Here is a passage from Michael Bowling’s article “Preservation Breeding and Population Genetics” from 1995:
“We all learned long ago that ‘inbreeding creates uniformity.’ If you take nothing else away from this discussion, at least cross that off your list of life’s basic concepts. Inbreeding drives genes to homozygosity and thereby shows up underlying genetic variance. Inbreeding actually creates phenotypic variability. Selection among the results of inbreeding may give rise to uniformity.”
Regarding your points #2 and #3 Lyman, yes, I agree, inbreeding is going to turn up foals with recessive traits in homozygous form. One example is SCIDS. But inbreeding by itself won’t purge those genes from the population, unless the breeder uses selection and stops breeding from all carrier parent that produce a SCIDS foal. Fortunately, these days we have a gene test and can avoid breeding two carriers together.
As for inbreeding creating more “prepotent” animals (point #4), I’ll give you an example. Both Carver DE and his multiple ancestor Ghadaf were chestnut, but Carver DE is no more “prepotent” for chestnut color than Ghadaf was. If you bred either one to the bay Davenport mare Magnolia, both Ghadaf and Carver DE would have a 50-50 chance of producing a bay foal, despite the many additional generations of inbreeding behind Carver DE. If instead of breeding to Magnolia, you bred either one to a homozygous bay Davenport mare, you’re going to get a bay foal, period. Chestnut is a homozygous recessive. So if a particular inbred stock is homozygous for a whole bunch of recessive traits, they will not be prepotent for those traits when bred to animals with the dominant alleles, no matter how much inbreeding is behind them.
Again, inbreeding drives genes to homozygosity. Whether the animal is then “prepotent” for the traits depends on whether those particular traits are dominant or recessive.
Go read the whole thing, it’s good stuff. Lyman later asks Jeanne Craver “Granted, you have a closed herd, but at the same time why breed full brother to full sister? What do you get from the selective inbreeding you have practiced?” I would like (however foolishly) to attempt an answer to Lyman’s question.
One of the miracles and wonders that is the Cravers’ involvement with the Davenports is that thought was always taken for the next several generations. It’s like watching a really good chess player, where the current move is dictated by the possibilities seven moves ahead. In this specific instance, for each horse who has had a major impact on the breeding group, a corresponding breeding group *without* that significant horse has been identified and maintained, and attention paid to differences in phenotype — as an outcross, or a counter balance. The non-Fasal group, the non-Tripoli group, and the non-Regency Schillas are all examples of this (smaller but still extant are the non-Dharebah Haifi and the non-Hanads).
There is a small problem with my terminology here, because what’s significant about (eg) the non-Hanad horses is not that there’s no Hanad; what’s significant is that they’re correspondingly rich in Antez ancestry. We say “non-Hanad” because it’s precise and easy, but it would be more descriptive to say “super-Antez” (not at all precise, alas).
Having set up this motion and balance within the overall breeding group, the next thing to do with a very significant horse is to inbreed on it — I think of it as the counter to the counter, which asks the question “what else is behind this significant horse that might be revealed?” Fair Sir and Fairlee CF are inbred to Tripoli and Dharebah; Levantine CF (illustrating this post) is inbred to Ibn Alamein and Bint Antan (by Regency CF out of his full sister Levant CF). The attempt to breed Javera Chelsea to Javera Thadrian is significant in the same way ("Thadrian is a force of nature" — Michael Bowling) and I have to applaud everyone involved for the work put in. (This was tried previously with another sibling, GH Janet, but the grand old mare just isn’t producing useful follicles any more.)
So my answer to the question of “what do you get from a full brother-sister inbreeding in the context of the Davenport group?” is “You get an answer to the question ‘What further phenotypical uniqueness might turn up from the genetic makeup of these horses who have already proven to be significant breeding influences?'”
Like I said, fools rush in.
Ambar-
I must admit, I am really not that familiar with Davenport bloodlines, although I have seen many Davenport horses and I must admit, they are very beautiful horses. But I really can’t comment much more than that at this point as to the particular attributes of different horses.
I do think that in that in some sense, ALL horse breeding practiced today is in some sense selective.
To own horses is to spend lots of money on horses. To breed horses is to spend even more money on horses. People don’t breed horses unless they are trying to propagate certain characteristics in the offspring which they determine, and which others will determine is worth something. To me, this is fundamentally selective in nature.
So the nuance between “selective inbreeding” and just plain “inbreeding” is, while a very important understanding and difference, I quite frankly, think is academic.
In a practical sense if you are inbreeding, you are practicing “selective inbreeding.”
I believe in the power of the market. I think the market is going to do a pretty good job of purging a horse from influence in bloodlines that exhibits undesirable characteristics as the result of inbreeding.
For your consideration.
Lyman
Lyman,
I agree with you that a horse that exhibits undesirable characteristics (whether or not these are the result of inbreeding) is not going to have a whole lot of influence on the breeding group as a whole. I’m not thinking of “undesirable” characteristics, however, just different.
Let me try to do a worked example with pedigrees and pictures.
Sire: Ascendant
http://davenporthorses.org/pedigree/A/ASCENDANT2e91e.HTML
Photo at the ripe old age of 28: http://davenporthorses.org/photos/Modern%20Horses/1970s/ascendant.jpg.php
Dam: Petit Point CF
http://davenporthorses.org/pedigree/P/PETIT_POINT_CF82466.HTML
Photo nursing her first foal: http://davenporthorses.org/photos/Modern%20Horses/1990s/Petit%20Point%20CF/petit-point-cf.jpg.php
So I hope you can agree, although I don’t have a lot of photos to choose from (I’m kind of appalled at how many side shots of my own mare I *don’t* have–) that these are basically the same kind of horse; medium neck set, nice hip, ought to look good in a Western saddle.
The sire has one granddam, the significant mare Ceres. The dam’s pedigree is a little poem to Portia, another significant mare. If inbreeding *doesn’t* produce variation, I should get something pretty consistent, right?
(If you want to make God laugh, tell Him your plans.)
Result: http://davenporthorses.org/photos/Modern%20Horses/Selene-25-July-2009.jpg.php
Upright in the neck, hinged at the poll, and in general rather more like her grandsire Monsoon than either parent.
So now we ask, what are our standards? Do we hold with the old cattlemen who valued consistency in a breeding herd so highly? Or do we prize this sort of variability in phenotype as a visible token of existing genetic diversity, which we have to treasure as we do our lives, if we want to see these closed breeding groups last another hundred years?
Both the “market” and “mother nature” are often cruel dictators, that do not take intrinsic quality into account. IMO!
I would argue that it is precisely because the market is SO cruel and SO extremely ruthless for it to be able to create the Arabian horse as we know it today.
WOW! Who knew I would start such a huge discussion with my question? But I am so grateful for all the information everyone is contributing. I just wanted to convey my thanks as I am leaving in 2 hours for Germany to see some horses with Davenport lines. I will read ALL of the posts when I get back and then tell all (and also about my August visit to Louis Baudain In Nemours to see his horses).
A presto,
Elena
Hi everyone and in particular, Jeanne Craver. The pictures Edouard posted of the stallion Levantine, triggered something in my mind, which is evident in the photos. I just finished posting a new entry on my blog, called LEGENDS, where I mentioned it (sorry, not trying to push my blog, Edouard) 🙂 .
For years, I have noticed (and admired) the metallic sheen on the coats of the Davenport Horses. It is a natural “glow” and not as a result of vigorous grooming. When the Royal Stud of Bahrain launched their website a few years ago, I noticed the same metallic sheen on their horses. I have also observed this metallic shine on some of the Akhal-Teke horses. My friend, Gari Dill-Marlow, who is a well-regarded Crabbet historian, enthusiast and breeder, saw the same metallic “glow” on the hide of Skowronek. She showed me a photo she had taken and well, son of a gun, if there wasn’t a glow radiating off Skowronek’s hide! I have wondered over this quality found in select Arabian Horses and for years now, have wondered if this shine is an indicator of authenticity/antiquity in our horses. I dont want to steal the discussion away from inbreeding, although I feel it is related but wondered why the sheen is more widely seen in the Davenports and the Bahrainis and not another closed group like the Babson program. On my mind today and apologies for my intrusion into this discussion. Congratulations Jeanne for breeding a beautiful horse like Levantine. I have always admired him for his classic beauty.
Have a great day everyone!
Ralph
We are proud of the metallic glow, and it is part of our horses. I do not know how it relates to asil status. It has nothing to do with grooming, as we made a point of not grooming some in their lives, other than their self-grooming rolling in the sand. I will say that sand brings it out, and clay covers it up!
Elena: we cherish good questions for just this reason; it gives us something to talk about. 😀
Anyone want to answer my question:
Is it possible to “improve” with a closed herd?
Ambar-
I am sorry, I can’t see your photos. I am in China at the moment and they block major portions of the internet here. For some reason, I can’t get to the site you referred to. It may use some type of photo sharing site that is blocked for whatever reason. I will have to get another program that gets around the blocking because it looks like the government has blocked the program I was using.
I will have to comment later on it.
Lyman
I have another question that I was thinking about that maybe Edouard or whoever can give me some information about:
Did the Bedouin tribes generally keep many mares and just a few stallions as a matter of practice?
Is it possible to “improve” with a closed herd?
Do you mean within a closed herd? Certainly, IMO. It might be difficult in some cases because you are restricted to the gene pool you’ve got. Selection is always important, whether you are outcrossing or inbreeding. It is the same. If you have a feature that is lacking in your closed herd, you may not be able to develop that, but very few features in Arabian horse breeding are single-gene, yes/no, on/off types of things. Sometimes you can work your way slowly toward improvements. Charles wrote an article, years ago, about breeding within a closed herd: deliberately choosing a restricted set of possibilities for the future. It is called “Nuns Fret Not,” after a famous poem by William Wordsworth. I’ll hunt it up for Edouard to post here.
“Nuns Fret Not” can be found here:
http://davenporthorses.org/2009/09/nuns-fret-not/
Ambar-
I finally was able to access your pictures online and comment.
I would be interested in seeing a picture of Selene at age 8 or 9. Until then it’s tough to figure out what a horse will look like.
About consistency and uniformity, I think it is tough for a breeder to judge if their own horses look similar or if there is variation. Of course I think that all my horses look different! I am sure others disagree.
It does seem to me that closed breeding groups that are heavily inbred do have their own “look.” You could see a horse and say, “that horse looks like a Davenport horse” or a Babson horse, or a Doyle horse, or whichever closed group you want. Of course within the groups, all the horses are different.
I think you could argue the same thing about the Arabian breed in general. Why do Arabian horses , generally speaking, have their own “look.” I would argue it is probably because the horses have been inbred over thousands of years. That’s why the Arabian horse makes such an improvement in other breeds of horses when bred to them. As Jeanne paraphrased Charles: you can not breed Arabian horses without inbreeding.
By definition, “Asil” Arabians are a closed group. Hence, they are inbred.
Anyone ever wonder why being “Asil” is important as a practical matter? I would argue that part of the reason is inbreeding.
If you introduce new genes to an inbred group, as the group continues to inbreed, science tells us that these new genes will continue to come out many generations later even if the non Asil blood is “small.” As Michael Bowling said: “inbreeding actually creates phenotypic variability.”
And to further develop Jeanne’s point, I would take it even further: breeding in a closed group is the ONLY way you can make sustainable improvements in future generations. The question is figuring out what closed group you are operating in: your own group of some particular importation, stud farm, region of desert Arabia, or the wider but yet still closed group of the “Asil” Arabian in general.
Lyman
I agree with you Lyman; the only hitch is agreeing what “improvement” is!
That’s the beauty of horse ownership. You get to decide what improvement is for yourself.
Hi Lyman,
Am very much enjoying your informed comments on this and other threads. One thing, though: Shouldn’t the “beauty” of being a horse owner be accompanied by “danger” and also “responsibility”? Shouldn’t so-called improvement always fall within the boundaries of what is best for the general health of the horse? I am thinking of a reference Jeanne made earlier on another thread to horses whose heads were so narrow they had not enough room for their teeth. Or perhaps are you assuming that true asil breeders always put the well-being of the horse first because the true asil breeder is him or herself already a breed apart? Just so you know, that question is a request for info, not a challenge. 🙂
Regarding the metallic glow: The first Davenport I ever saw in my life was the stallion CF Banter. He was in a dark barn in Vermont–more like a cavern actually. His (bronze)metallic glow was so intense it seemed as if there was a bright light inside of him. I never saw anything like it. His owner had fallen on hard times and she was desperate to sell him, but I was afraid to have a stallion. One of the bigger mistakes of my life! I should have tossed in the back of my station wagon. (He was small enough.) I later heard he ended up the happy, spoiled pet of a family in NH.
Elena, it would have been nice if you could have gotten Banter CF. In a 1990 visit to the NE I got to ride him. He was a wonderful horse, noble yet wonderful temperament and I think you would have found him a joy to live with as your first stallion. Yes he did have a sheen about him.
I have also seen that metalic like sheen on a wide variety of Asil horses over the years. As for Davenport bloodlines, in 1978 when I first saw the rare and unreplaced stallion ASF Cicero (Pericles x Ehwat-Ansarlah) a 1970 copper chestnut, he was in Canada standing in a long darkly lit row of rather untidy tie-stalls with other stallions in tie stalls. From nearly 50 feet away he shined with a glow like a new copper penny with a sheen that stood out in the entire aisle. I did not even know who he was but rushed up to his tie stall to see him and pet him. He turned his handsome masculine head with huge eyes around to see me an it was if he was the only groomed stallion in the row but he was not groomed. It is almost as if the sheen contains some sort of natural residue that prevents, to some extent, dirt from adhering. My stallion Fa El Echo (Char Echo x Sirbana) was a dark mahogany bay but he also had a kind of shiny glow to his coat even in winter and he often looked groomed just because of the remarkable sheen. Judith Forbis recalls fondly the impression that the RAS stallion El Sareei (Shahloul x Zareefa) 1942 bay, made on her. He also had that sheen and it shows in some of her photos of him. I don’t know that such a sheen is any unique bloodline marker, maybe just a quality that varies from from horse to horse regardless of bloodlines.
Joe,
I think about Banter all the time. I think I saw him in ’92. I had (and still “have” though he is on permanent loan and always watched over) an enormous Thoroughbred Hunter/Jumper who was a love as long as I was on the ground but once I was on his back it was another thing. So, one hematoma the size of NJ, one concussion, 3 broken ribs later (all different accidents because I always got back on) I went to see Banter. He had just been standing stud out at Craver Farm for a while. His owner lead him past several mares (at least one was in heat). I got on and Banter looked down at a garden hose on the ground. He went backwards faster than I did when a Moray Eel shot out of its cave one day when I was diving. I got right off. Stupid? In the extreme. He was so perfect. And that glow! I have never seen that again.
But Joe–I think I’m on the verge of buying a Tunisian colt. Don’t want to say too much yet, but if I do I will be posting about him.
Thanks for sharing your memories of Banter.