Category Archives: Genetics

Reconstructing Domow

A persisting question in the breed’s North American history, since coat color inheritance first came to be widely understood, revolves around the identity and parentage of the mare Domow. Biology and history working together provide a start toward the puzzle’s solution. By Michael Bowling and Robert J. Cadranell II, Copyright © 2001. Initially published in CMK Heritage Catalogue IV. Used with permission.

Domow is officially a 1913 (no month or day given) bay daughter of the two chestnuts, *Abu Zeyd and *Wadduda. That parentage is not compatible with established principles of coat color inheritance, if the colors of all three horses are correctly attributed. Domow produced the bay Tabab by a chestnut, and he sired bay foals out of chestnut mares. Enough of *Abu Zeyd’s hide is preserved at the American Museum of Natural History to eliminate any doubt that he was chestnut (Charles and Jeanne Craver, personal communication). No evidence from photos or contemporary descriptions, or from the balance of her breeding record, provides grounds to question that *Wadduda was chestnut; in fact some contemporary references make her “sorrel” which suggests, if anything, a light shade of chestnut. One reasonable explanation for Domow’s registration would be a switch of *Wadduda’s 1913 foal with another in the same ownership. The Arabian Horse Registry of America (AHRA) record shows Domow bred by Hingham Stock Farm (Peter B. Bradley). Although she was registered by Bradley, based on other information Domow clearly came out of the small personal Homer Davenport program, in Holmdel N.J. The original options there for exchange with Domow were Fahreddin, registered as the 1913 foal of the bay *Abeyah, and Sabot, the 1913 foal of the bay Sira, of the Basilisk family. Both were fillies registered as chestnuts, from matings capable of producing a bay foal (their sires were chestnuts, *Abu Zeyd and *Euphrates respectively). The foal switch question has now been addressed thanks to developments in DNA technology.

Mitochondrial DNA (mtDNA), in contrast to the nuclear chromosomes, is transmitted strictly through the egg cytoplasm and does not undergo meiotic recombination. Characteristic mtDNA sequences (haplotypes) of dam lines change only by rare mutations, and are stable over many generations. Questions of maternity can be addressed, within historical stud book time frames, by comparison of mtDNA sequences, if direct female-line descendants are available of the questioned individuals and of other representatives of the relevant dam lines, and so long as questions can be defined in an either-or sense. mtDNA haplotypes were derived (see Bowling, A.T., Del Valle, A. and Bowling, M., 1998. Verification of horse maternal lineage based on derived mitochondrial DNA sequence. Journal of Animal Breeding and Genetics 115: 351-356) from tail-female descendants of Domow through her daughters Dowhana and Zenee; of *Wadduda through two daughters, Moliah and Aared; of *Abeyah through two daughters (Saba and Samit) of the only persisting source of this female line, her imported daughter *Haffia; and of Sabot through the line of her daughter Azreka. A matching Basilisk haplotype was derived through the independent branch from *Butheyna.

The Domow haplotype matched that of the *Wadduda family and was distinctly different from those of *Abeyah and Basilisk, which does not support a foal switch involving Fahreddin or Sabot. After these results were obtained, further research at the Arabian Horse Owners Foundation (AHOF) among the archived records of *Abu Zeyd’s and Fahreddin’s subsequent owner gave substantial support for Fahreddin’s having been foaled in 1912, rather than 1913, which would have ruled out from the start any easy scheme for exchanging the two. [Note added in 2007: the 1912 foaling date for Fahreddin proved to be an error.]

The Domow question has been complicated because *Abu Zeyd is credited in AHRA records with another bay foal out of a chestnut dam, the 1920 filly Radi. Correspondence in the same archives records a second owner’s request for assistance in having Radi’s registered color changed from chestnut to bay, which leaves room for the possibility of accidental or deliberate substitution. This example at least is not supported by documentation sufficient to question *Abu Zeyd’s genetic contribution in the absence of parentage verification, and in face of the genetic stability of the coat color alleles involved. Radi has no recorded offspring, so her color and parentage (or identity) are chiefly of academic interest, unlike those of the prolific and influential Domow. Radi’s case does underscore that the stud book record alone might not provide the whole story when addressing historical questions.

A further possible complication involves two of Domow’s granddaughters: Kirah (1925, by a chestnut Domow son and out of a bay mare) and Aatika (1926, by Domow’s bay son Tabab from a chestnut dam). In their original registration (the 1927 Arabian Stud Book) their color is abbreviated “s,” although “sorrel” is not listed as a color option in that book. In the 1937 volume both mares’ color has been changed to “b” but by 1944 it has become “ch;” both are given as “chestnut” in the current AHRA pedigree database.

Eye witness accounts confirm the bay color of both Aatika (Helene Asmis Clifford, personal communication) and Kirah, described in Reese and Edwards’ The Kellogg Arabians: their background and influence as “a dark rich bay.” Aatika produced the bay Lulu by the chestnut Asil, and Lulu produced the bay Lurif by Rifage, a grey who did not transmit black pigment (he got only a handful of bay foals, out of over 100 registered offspring, and none from chestnut dams). Kirah never produced a registered foal to a chestnut sire so no test mating results are available for her. Further inspection shows that Kirah’s and Aatika’s breeder also allowed to stand the prior registration of the well-known liver chestnut stallion Hanad as “b” and that he used “seal” as a color term, in correspondence available at the Trust. The chestnut error in the two mares’ registered color may reflect picking up the original “s” entry and mistaking it for “sorrel” during the preparation of the 1944 Stud Book, and could also be related to the correction of Hanad’s color in that volume.

All this coat color backing and forthing could be taken to support the ideas sometimes presented, that *Wadduda was a light bay, or alternatively that Domow was an off-shade chestnut. One can only say Domow and *Wadduda both were well-known mares in their lifetimes and nothing suggests either color assignment ever was questioned; the breeding record supports the bay color in all cases but Kirah’s (not tested). In the absence of color photography the images available of Domow, Tabab, Kirah and Aatika show them as bay, while *Wadduda does not look bay in her photos.

*Abu Zeyd, *Wadduda and Domow are extensively represented in modern Arabian pedigrees, through multiple offspring of each. In terms of gene frequency, anomalous color designations would be of regular occurrence had the Domow coat color incompatibility possessed a genetic basis separate from incorrect parentage. At this point the simpler explanation would have Aatika’s and Kirah’s breeder (who had no connection with the original registration of Domow) unfamiliar with standard horse coat color terms, or perhaps inexpert at recognizing ultimate coat color from foal coats. Some bay foals can have quite light-colored manes and extremities, and Mrs Clifford remembers that Aatika also sun-faded extensively in the summer.

If Domow was not switched with another filly and if her color and her dam’s were correctly recorded, it becomes necessary to seek the black pigment gene through a sire available to cover *Wadduda in 1912. Paternity, as opposed to maternity, can be addressed only on historical grounds: unlike the special case of mtDNA with dam lines, no biological tests of paternity can be applied at such a distance of time and generations and in the absence of physical samples from putative parents and offspring. In this particular case the relevant breeding records have not been located. A possibility must be acknowledged, that *Wadduda may have been covered accidentally, during the transitional period after Davenport’s death in 1912 and by a frankly unknown sire. Resolving that question suffers under the notorious difficulty of proving a negative, but it is not the only reasonable reconstruction.

The published record supports the interpretation that *Wadduda’s 1912 covering was actually part of a last phase of normal activities. *Wadduda foaled the filly Amran on 19 April, 1912; Homer Davenport fell ill on the evening of the 19th and died on 2 May. Only in the last few days of his illness was Davenport’s condition recognized to be life-threatening. While it is possible to picture that orders to breed *Wadduda might have been conveyed from the sickbed, it is less likely that an order to shut down the horse activities would have come under those circumstances; during the first week or more it would not have been thought necessary, and during the final few days, the horses might well have been the last thing on the minds of those in attendance. The agents in charge of Davenport’s horses in New Jersey would reasonably have carried on according to previously received instructions, which must have included at least general plans for mating the mares in 1912. The other foals registered from 1912 breedings to stallions owned by Davenport have known foaling dates, which were early in the 1913 season: Sabot and Omar in January, and Abeleyd in February. (The “1 January” 1913 foaling date of Domow in the AHRA database is a place holder, not a recorded birth date.)

*Wadduda was clearly an easy breeder and produced a registered foal every year from 1907 through 1913: she produced for Peter Bradley’s Hingham Stock Farm again in 1915 and ’16 (and died in time for her death to be noted by 1918). She had foaled a week later in 1908 than in 1907, 24 vs 17 July—but in 1908 through 1912 she foaled earlier each succeeding year, respectively on 24 July, 10 July, 10 June, 13 May and 19 April. Progeny records for others of the early Bradley and Davenport mares also support a policy of foal heat breeding (more likely than a high incidence of short gestations among that population). If it was normal practice to cover *Wadduda on her foal heat, and if such a policy had been followed in 1912, she would have been the last mare covered during Davenport’s life and according to his instructions.

*Wadduda’s 1912 covering sire was not, ex hypothesi, either of the chestnuts *Abu Zeyd or *Euphrates. The bay *Gomusa appears to have been among the horses in Davenport’s possession in New Jersey (his last recorded foal was in 1912). Davenport also had imported from England, in 1910 along with *Abu Zeyd, two Crabbet colts: *Berid, a 1908 grey with a chestnut sire, but whose dam could have provided black pigment—she produced all greys or bays out of her 12 foals—and *Jahil, a 1909 bay. Davenport bred two bay 1910 colts, Daghar and Jerrede; the last-named was sold from “the old Davenport place” in 1914 so likely was in residence through this whole period. Daghar was owned in Chicago by May 1915 but no date for his original sale has turned up.

*Jahil was transferred to H.J. Brown in January of 1912; Brown is his published owner in 1913 and used him in the spring of 1912, so he at least can safely be eliminated from consideration. This leaves all or some of *Gomusa, *Berid, Daghar and Jerrede in the running to provide a sire for Domow, and speculation has centered on an accidental or mis-recorded mating involving one of those four. There remains another possibility first raised based upon a fleeting reference to *Astraled in connection with Davenport, in Lady Anne Blunt’s published Journals and Correspondence.

F. Lothrop Ames of Easton, Mass. was a member of an established railroad and industrial family who was caught up in the early flurry of interest in Arabian horse breeding. He bought the yearling filly Rosa Rugosa from Spencer Borden in 1908 at a “four figure” price, and in 1909 went to Crabbet for the proven sire *Astraled along with two mares, *Shibine and *Narda [II]. Ames owned his Arabians for only a short time, and all his registrations were with the Jockey Club, so AHRA records do not touch on his activities. His grandson does not even remember any family tradition that Ames imported or owned Arabian horses, and nor does the son of Ames’ long-term horse trainer, who came on board just a few years later (Frederick Ames Cushing and John Hogan Jr, personal communication), although *Astraled and *Narda II would found two of the great sire and dam lines of the breed. *Narda’s son *Crabbet was gelded but he still is renowned as winner of the 1921 U.S. Mounted Service Cup (also known as the Army endurance test).

In May of 1912 Lady Anne commented, to Spencer Borden who had just written to inform her of Davenport’s death, that “he wrote to me about Astraled, full with enthusiasm. Do please secure Astraled. I always wished you to take him.” It is difficult not to read a great deal into this brief passage. Why would *Astraled be available for Borden to “secure,” immediately after Davenport’s death, if the horse had just been reported in some situation about which Davenport could be “full with enthusiasm”? Davenport’s enthusiasm must have been related to his own plans for the horse, for *Astraled to have become available as a direct consequence of Davenport’s death. Again in August of that year, Lady Anne pointed out that “if you took Astraled” Borden could breed a near relative to Riyala, who was not available for sale, from a related mare *Risalda he already owned.

Neither Davenport’s letter which mentioned *Astraled, nor Borden’s to Lady Anne notifying her of Davenport’s death, can presently be located. The following passage from the 1945 first edition of The Authentic Arabian Horse makes it clear that Lady Anne’s daughter Lady Wentworth was working from at least the Borden side of the exchange, if not Davenport’s letter as well:

“Mr. Ames bought the famous Crabbet stallion Astraled, and when Ames ‘fell down and quit’ as Borden put it, Davenport bought all the horses he had purchased from the Blunts except ‘Crabbet.’ Ames had offered Borden the seven head with his Rejeb mare [*Narda II], Rosa Rugosa [the filly Ames had bought from Borden some four years previously] and Shibine for 2,000 dollars; but they were in such bad condition that he did not purchase, intending to get them even cheaper in the spring. Meanwhile his old enemy Davenport secured them…”

Note even the coincidence of the verb “secure” which Lady Anne had used in her letter. The references to “poor condition” (exaggerating that would have been quite in Borden’s style, just as it was like Lady Wentworth to gloss over Borden’s 1909 report to Lady Anne that he and Davenport had resolved their prior disagreement) and waiting to buy the horses “in the spring” puts this exchange somewhere in mid-winter, which fits well with Homer Davenport’s published letter of February 1912 looking forward to better financial days because he had returned to W.R. Hearst’s employ. A February or March, 1912, date fits, too, with the likely timing of *Shibine’s breeding to *Euphrates (she foaled Abeleyd on 27 February, 1913). If Davenport believed all the horses he bought from Ames were “from the Blunts,” and if his successors transmitted that impression to the next owner, this could also explain the old puzzle of how Rosa Rugosa came to be registered as bred by Crabbet Stud and imported by Borden (her actual breeder).

No published stud book shows *Astraled in any other ownership between his importer Ames (American [Jockey Club] Stud Book, 1910) and the Rev. Thomas Sherman (Arabian Stud Book, 1918), who owned *Astraled in Washington State and would later donate him to the U.S. Remount. Spencer Borden did breed that *Astraled/*Risalda foal, a 1915 colt, and he also showed *Astraled at least once. Apparently Borden sold *Astraled to the Rev. Sherman; *Astraled’s registration, on file at the Trust, is noted “no certificate issued” which implies he had already left for the Northwest and was being put on the books to provide a registered sire for his two U.S. foals. Other registrations in the same numerical sequence were such posthumous ones as those of General Grant’s *Leopard and *Linden Tree.

The other substantial connection of *Astraled indirectly to Davenport is an original manuscript stud record preserved at AHOF, begun by H.J. Brown for his own short-lived Arabian program. The stallion section includes a page for *Astraled, with the undated notation “Sold to Borden.” Why should Brown have had occasion to devote a page to *Astraled and still less to mention the horse’s sale in his private records, unless he had been the owner and thus the seller? It is a matter of record that H.J. Brown bought Davenport’s stallion *Abu Zeyd, and the Ames imported mares, one of which produced a 1913 foal by Davenport’s *Euphrates. Taking all these facts together, the simplest reading has the Ames Arabians, including *Astraled, pass from Ames to Davenport to Brown. *Crabbet was registered later than the mares, which is consistent with his having been temporarily separated from them (if Davenport bought everything “except ‘Crabbet'”).

Domow herself was not registered until she was five, by which time not only her exact foaling date, but Davenport’s connection with the Ames Arabians (certainly *Shibine, if not more of them) seems to have been forgotten. Domow’s markings of a blaze and three stockings could have been taken as evidence that her sire must have been the flashily marked *Abu Zeyd, even had *Astraled (whose only marking was a faint snip) been named, the more so given the apparent lack of a paper trail connecting Davenport with the Ames Arabians. The fact that the bay-chestnut coat color difference is simply inherited while markings are highly unpredictable may well have been unknown to the Hingham management; the science of genetics still was in its infancy, even though Hurst’s 1906 study of Thoroughbred coat colors was the first illustration of a Mendelian character operating in a mammal. Even today one encounters otherwise sophisticated horse breeders who are unclear on the details of coat color transmission genetics.

Domow was highly regarded as an individual and produced 11 registered foals in five ownerships. Her immediate descendants included significant horses in several important foundation breeding programs, including those of W.K. Kellogg and Roger Selby, and she figures in the pedigrees of preservation-bred Arabians and of such influential sires as Bey Shah and Khemosabi. Among 100 animals in a random sample of AHRA registrations (mostly 1993 foals), Domow appears in 69, or roughly 70% of the pedigrees.

Again, given the difficulty of proving a negative, one cannot expect to show that it was impossible for any stallion to have jumped the fence during what must have been an unsettled period, after Davenport’s death. *Wadduda’s previous production record is consistent with a deliberate foal heat breeding, which in turn supports the idea that the mating took place while Homer Davenport was alive. If *Astraled really was in Davenport’s possession along with *Abu Zeyd—and the odds do favor that reading—the confusion of these two imported senior stallions, both Mesaoud sons and both sold to H.J. Brown, is easier to picture than any other simple scenario involving a mistake in reporting the sire involved in a deliberate breeding. Much of our reconstruction remains strictly unproven, but we see a strong case for Homer Davenport’s having owned *Astraled, in time to make that horse a serious candidate to have sired Domow.

Note added in 2007: Since this writing research in New Jersey court records has confirmed that *Astraled definitely was in Homer Davenport’s possession at the time of his death.

To expand on the previous note, in 2008: The court records not only confirm Lady Wentworth’s report that the Ames horses, except for *Crabbet, were in Davenport’s possession in 1912; they put most of the J.A.P. Ramsdell horses in his hands as well; and document that *Abu Zeyd and *Astraled were accounted the head sires of Davenport’s Holmdel Stud. In light of this further research *Astraled remains the most likely alternative covering sire for *Wadduda in 1912, if the breeding was not an accident.

Further, W.R. Brown correspondence at AHOF indicates that Fahreddin most likely was foaled in New Jersey, and that she was apparently never in Peter Bradley’s possession. If Domow were also foaled in New Jersey and went to Bradley at her dam’s side, it would explain why Bradley had no foaling date for her.

What’s In A Name? Counting Doves a Century After They Hatch (part 2)

This entry is part [part not set] of 3 in the series What's In A Name?

Copyright © 1998 by Michael Bowling
(with particular thanks to Margaret Dickinson Fleming)
originally published in Arabian Visions Oct 1998
used by permission

(with added photos)

After the early 1930s the BINT YAMAMA horses were universally referred to as of the Kehilan Jellabi strain. In later editions of PASB the strain of KAFIFAN was changed to Kehilan. No hint of a connection between Prince Mohammed Ali’s [BINT] YAMAMA and YEMAMEH, the dam of MESAOUD, was ever suggested, and a substantial tradition grew up that BINT YAMAMA was a daughter of the Sheykh Obeyd YEMAMA, sometimes even to the point of suggesting BINT YAMAMA had been bred at Sheykh Obeyd.

Speculation is fruitless but also inevitable. Perhaps BINT YAMAMA was known to be half-sister to, or from the family of, “Lady Anne Blunt’s horse” and this came to be taken as a reference to one of the Blunts’ several Jellabi horses from Ali Pasha Sherif (besides YEMAMA there were MERZUK, KHATILA, MAKBULA, KERIMA, KASIDA, FEYSUL, JELLABIEH and MANOKTA), rather than to MESAOUD. Possibly the existence of a “BINT YEMAMA” daughter of the Sheykh Obeyd mare had become known in some circles, although access to Lady Anne Blunt’s stud records was strictly limited after her death. That name belongs at Sheykh Obeyd to a bay mare without a grey parent, foaled in 1904, who left Egypt for Greece in 1906; she cannot have had anything to do with a grey mare some 10 years older who appeared in 1908 in the Manial Stud.

Prince Mohammed Ali also commented that [BINT] YAMAMA “was a beautiful mare and produced till her age of 25.” If her last foal was the 1918 colt *NASR—there is no record of a later one—then this implies she was foaled in 1893, the same year as YASHMAK, so they could not have been out of the same dam anyway. If BINT YAMAMA produced a foal after *NASR then she was foaled later than 1893, when the bay YEMAMA was in the possession of the Blunts and her time is fully accounted for. The bay mare had some unnamed colts between YASHMAK and IBN YEMAMA, but no fillies until the BINT YEMAMA of 1904.

This was where matters stood on the 1986 publication of Lady Anne Blunt’s Journals and Correspondence. Lady Anne’s writings make it clear that she and Prince Mohammed Ali were on visiting terms and she repeatedly listed the mares, with their strains, that he possessed. Not only is no animal of the Kehilan Jellabi strain mentioned, but it is flatly stated that among his best mares is “the Seglawieh Yemama (daughter of the old Yemama, dam of Mesaoud),” and again that her dam was “Yemama owned by the Khedive.” These statements contradict over 50 years of accepted pedigree tradition, but it is worth noting that Lady Anne Blunt’s is the only contemporary reference we have to the matter. Not only was she writing at the time these horses and breeders were living, but she took particular interest in Arabian horses of Ali Pasha Sherif ancestry, in horses related to her own, and in the strains and origins of the horses which her contemporary breeders showed her.

Table: Yemama Bay and Yemameh Grey
Name Color DoB Breeder Produced for
Yemameh gr pre-1880* Ali Pasha Sherif Ali Pasha Sherif, Abbas Hilmi II
Yemama b 1885 Ali Pasha Sherif [?Moharrem Pasha], Lady Anne Blunt
*her first known foal was a full brother to Mesaoud, aged 4 in January 1884

In 1998 it became possible to address this pedigree relationship with the techniques of molecular biology (see Sidebar: The Science). Mitochondrial DNA (mtDNA) had already been used to reject the hypothesis that the coat color incompatibility in DOMOW’s registered parentage could be explained on the basis of a foal switch in 1913. Sequences from the mtDNA of tail-female descendants of DOMOW matched those of other *WADDUDA descendants, and were different from those of *BUSHRA and *ABEYAH descendants, these being the other dam lines from which fillies were available to be switched with DOMOW.

Addressing this Ali Pasha Sherif question demonstrates how the technique can be applied another 20 years or more back in time. It was possible to compare mtDNA from the three relevant families: direct female line descendants of 1) BINT YAMAMA; 2) BINT HELWA (attributed to the female line of MESAOUD and so of his dam YEMAMEH); and 3) MAKBULA, of Ali Pasha Sherif Jellabi origin (only one source of this family is recorded, the mare known as JELLABIET FEYSUL from Ibn Khalifa of Bahreyn, although the exact interrelationships among the Jellabi horses are not clearly stated).

In short, the mtDNA of the BINT YAMAMA descendants matched that of the BINT HELWA horses, and both were different from the MAKBULA descendants. Based on this testing, the conclusion is that BINT YAMAMA was indeed half-sister to MESAOUD, and not from the dam line which produced MAKBULA.

Postscript: Names and Identities

It is important to remember that the nature and identity of Prince Mohammed Ali’s mare have never changed; she has throughout been the same horse she always was. What has “evolved” over the decades is our knowledge about her.

Both Prince Mohammed Ali and Lady Anne Blunt refer to our subject mare and her dam by the same name, but the export pedigrees uniformly give her as “BINT YAMAMA,” and her dam as “YAMAMA,” a daughter of “WAZIRIEH” or “WAZIREH” from the stud of Abbas Pasha. This YAMAMA now appears to be identical with the dam of MESAOUD, the mare Lady Anne Blunt refers to in her stud records as YEMAMEH.

Since the 1920s YEMAMEH’s dam has been known as BINT GHAZIEH, but it may be that she had what might be called a “personal” name (BINT GHAZIEH is a description, “daughter of Ghazieh,” as much as it is a name, and as with the Banat Nura, might have been a generic term for any mare of the GHAZIEH family). In fact MESAOUD’s second dam’s name may actually have been “WAZIRIEH.”

This could be a reasonable name for a sister to WAZIR, as this mare was; further, this gives a possible origin for the confusing reference in Lady Anne Blunt’s journal to MESAOUD’s dam as sister to WAZIR, which seems improbable on chronological grounds (Peter Upton, personal communication): on a hasty reading, the dam’s name WAZIRIEH might look like a reference to YEMAMEH herself as sister to WAZIR. Unfortunately the relevant page of the document in question apparently has not survived for comparison with the journal entry.

The Science

Mitochondrial DNA (mtDNA) codes for some of the proteins of the mitochondria, the “energy furnaces” responsible for cellular respiration. Mitochondria reside in the cell’s cytoplasm, not in its nucleus, so mtDNA is transmitted independent of chromosomal inheritance. In the nature of mammalian reproduction, the sperm cell’s mitochondrial contribution is swamped by that of the vastly larger egg cell, and so mtDNA is inherited for practical purposes through the female line, uninfluenced by the sires used over the generations.

A part of the research program at the Veterinary Genetics Laboratory of the University of California at Davis involves the development of techniques for analyzing mtDNA. An advantage of mtDNA testing is that, in sharp contrast to nuclear genes, it can be applied even at many generations’ remove to address questions of maternity, provided direct female line descendants of the animals in question are available. A scientific manuscript surveying the usefulness of mtDNA comparisons for use in Arabian horse parentage testing is in preparation.

The march of science

Since 1998, it’s been shown that there is a specific enzymatic system which eliminates the sperm mitochondria from the developing embryo—the male contribution is not just overwhelmed by the numbers in the egg cytoplasm, as was believed then; there actually is none under normal circumstances. — mb, April 2004

The mtDNA identity of the descendants of BINT HELWA and BINT YAMAMA has one further very interesting direct implication. The pre-stud-book pedigrees of the Ali Pasha Sherif and Abbas Pasha Arabians are properly referred to as traditional beliefs. They are not documented pedigrees as would be the case for horses whose parentage is published in a stud book. It appears that the mtDNA results actually link the descendants of two GHAZIEH daughters: HORRA, second dam of BINT HELWA, and WAZIRIEH or BINT GHAZIEH, second dam of BINT YAMAMA. This strongly implies an actual existence for GHAZIEH and reinforces the reality of at least this particular set of traditional pedigrees.

Scientific papers:

  • Assignment of maternal lineage using mitochondrial nucleic acid sequence in horses, J.A. Gerlach, A.T. Bowling, M. Bowling and R.W. Bull. 1994. Animal Genetics 25: Supplement 2:31.
  • Mitochondrial D-loop DNA sequence variation among Arabian horses, A.T. Bowling, A. Del Valle and M. Bowling. Animal Genetics 2000 Feb;31(1):1-7.
  • Verification of horse maternal lineage using mitochondrial DNA sequence, A.T. Bowling, A. Del Valle and M. Bowling. Journal of Animal Breeding and Genetics, 115 (1998), 351-355.

Sources:

  • Unpublished pedigrees and other documents from the files of Traveler’s Rest Farm, courtesy Margaret Dickinson Fleming
  • The General Stud Book
  • The Polish Arabian Stud Book
  • The Arabian Horse Families of Egypt, Colin Pearson with Kees Mol
  • The Banat Nura of Ali Pasha Sherif,” Robert J. Cadranell II (The CMK Record XI/2)
  • Egypt and Cromer, Afaf Lutfi Al-Sayyid
  • Journals and Correspondence 1878-1917, Lady Anne Blunt, edited by Rosemary Archer and James Fleming
  • My Diaries, Wilfrid Scawen Blunt
  • Secret History of the English Occupation of Egypt, Wilfrid Scawen Blunt

What’s In A Name? Counting Doves a Century After They Hatch (part 1)

This entry is part [part not set] of 3 in the series What's In A Name?

Copyright © 1998 By Michael Bowling
(with particular thanks to Margaret Dickinson Fleming)
originally published in Arabian Visions Oct 1998, used by permission

(with added photos)

Names in 19th-century Egypt do not appear to have been the hard-edged entities we would like them to be; Ali Pasha Sherif himself first comes to our attention, buying horses at the auction put on by the heirs of Abbas Pasha, as “Ali Bey.” Who would realize at first glance that “Ibn Yemameh al-Saghir” on Ali Pasha’s own 1889 sales list is the same horse as the great Blunt sire MESAOUD?

Not only did the same horse (or person) appear under different names, the same or very similar names could be used for different horses. Different names may be spelled similarly, or the same name may be Westernized differently; the potential for spelling differences of transliterated Arabic names is almost infinite. The convention used varies not only with the native language of the writer but with the scholarly tradition to which s/he subscribed, and with the brand of Arabic native to the speaker or writer being transcribed (Susan K. Blair, personal communication).

Arabian mares appear to have suffered from a particular lack of nomenclatural precision. The same name might routinely be used for several generations of a dam line, or for a set of full and half sisters, or indeed for mares even more nebulously connected (cf Cadranell, “The Banat Nura of Ali Pasha Sherif“). How many mares named with some variation on “Yamama”—”Dove”—actually lived in Egypt in the 1890s? There were at least two.

The Khedive Abbas Hilmi II was 17 years old and at school in Vienna when he succeeded his father Khedive Tewfik as ruler of Egypt in 1892. The story of Abbas Hilmi II and his relationship to British colonial power is a sufficiently complex subject to qualify in its own right as a historical specialty, but the last Khedive also figures in Arabian breed history. On his return to Egypt to take up the position of ruler of that country, he began to breed Arabian horses, in the tradition of his great-grandfather Abbas Pasha I. One of his first acquisitions, the Ali Pasha Sherif mare YEMAMEH, had already produced the Blunt sire MESAOUD. Wilfrid Blunt in his diary mentions that on 11 January, 1896 he “[t]ook Anne and Judith to Koubbah to see the Khedive. He… showed us his stud. He has got together some nice mares, but nothing quite first class, except two of Ali Pasha Sherif’s, one of which is our horse Mesaoud’s dam, a very splendid mare, with the finest head in the world. He has bred some promising colts and altogether the thing is well done.”

Wilfrid and Lady Anne Blunt also bought a mare named YEMAMA in 1892. According to the original GSB registration for her son IBN YEMAMA, she was “stated to be an Abeyah, a bay mare brought from a desert tribe, through a Tiaha sheykh, to Mohammed Thabit, Sheykh of the Sualha tribe, in the Sherkieh Province, for Ali Bey Shahin, son of Shahin Pasha, and purchased from Ali Bey Shahin.” YEMAMA produced at Sheykh Obeyd from 1893 through 1904, taking time off for adventure in 1897—she served as Wilfrid Blunt’s mount on his eventful last desert journey. YEMAMA’s named offspring at Sheykh Obeyd were the grey 1893 mare YASHMAK by *SHAHWAN, and the 1902 and 1904 bay full siblings IBN YEMAMA and BINT YEMAMA by FEYSUL. YEMAMA was given away in 1906, aged 21; her only link to modern pedigrees is through her grandson IBN YASHMAK, taken to England in 1904 and returned to Egypt in 1920.

In a 1907 journal entry Lady Anne Blunt records a visit from Moharrem Pasha and a discussion regarding YEMAMA, “that bay mare Moharrem Pasha sold to us—to which the Pasha replied ‘O! that mare, the Jellabieh I had from Ali [Pasha] Sherif!” Later in the same entry “Ghania’s long tale about Yemama having passed through several hands on her way from the desert is all a fabrication!!!” This reads as though Ghania had been Moharrem Pasha’s agent in the 1892 sale of YEMAMA. The answers to other questions that come to mind (eg, how Ali Bey Shahin comes into the story, and why Moharrem Pasha is not mentioned in the mare’s GSB provenance) are not clear at this time.

Abbas Hilmi II was deposed by the British in 1914 and from that time lived in exile and never returned to Egypt. Most Arabian horse enthusiasts today are probably more familiar with the name of the last Khedive’s younger brother. Prince Mohammed Ali Tewfik continued to breed Arabians at his Manial Stud in Cairo for nearly 20 years after Abbas Hilmi went into exile. The Manial Stud provided foundation stock to the Royal Agricultural Society, to the Inshass Stud of the Prince’s cousin King Farouk, and to breeders in Poland, Germany and the U.S. The Prince’s name is enshrined in our stud book as a prefix to two of the mares he sold to W.R. Brown. HAMAMA 418 and *HAMIDA 509 already were registered, so the two Egyptian imports with the same names became *H. H. Mohammed Ali’s HAMAMA 887 and *H. H. Mohammed Ali’s HAMIDA 889.

Prince Mohammed Ali’s most esteemed line of horses was founded by the grey BINT YAMAMA, bred by his brother. In a 1933 letter to General J.M. Dickinson of the famed Traveler’s Rest Farm in Tennessee, the Prince wrote that he had exchanged a black gift stallion from Sultan Abdul Hamid II of Turkey, plus 200 pounds, “to get [Bint] Yamama, wich [sic] was in the possession of one of my brother’s people.

This exchange can be roughly dated to 1908; Lady Anne Blunt’s published Journals and Correspondence record that she saw the black stallion from the Sultan in December of 1907, while a year later a daughter of YEMAMA [sic] is among “the principal mares.” The same mare is mentioned in similar terms again in January of 1911; in February 1912 she is accounted the second best of the mares, and parenthetically “the dam Yemama owned by the Khedive is dead.”

Ten Manial Arabians of BINT YAMAMA’s descent in the direct female line were used for breeding in Poland, in Germany and in this country (imported by W. R. Brown and Henry Babson). This breeding element is a widely influential one in international pedigrees; to pick a few names at random, KONTIKI, BEN RABBA, KHEMOSABI and many horses of the Al-Marah and Shalimar programs carry this Manial breeding. It is behind the majority of horses bred from Germany’s Weil-Marbach lines. There is also a strong tradition of breeding straight Egyptian Arabians carrying more or less of BINT YAMAMA’s influence (see Sidebar: The BINT YAMAMA Influence Summarized).

General Dickinson, on buying four of the Manial Arabians imported by W. R. Brown, had noticed a discrepancy in their strain designations, compared to that of KAFIFAN, a stallion from the same family which Prince Mohammed Ali had sold to Count Potocki of Poland in 1924. The Brown imports were given as Jellabi or Kehilan Jellabi; KAFIFAN, in the original (first edition) Polish Arabian Stud Book (PASB), was registered of the strain “Saklawi Djedran.” General Dickinson later bought from Poland the KAFIFAN daughter *MATTARIA, and in the summary of her ancestry supplied by the Polish registration authorities (the source would have been the records of the Potocki family) KAFIFAN also appears as “of the Saklawi family.”

Asked to comment on this apparent contradiction, Prince Mohammed Ali stated, not that PASB was in error on the strain of KAFIFAN, but that “[t]he Kehilan-Jellabi are descending from the Seglawi-Jedran.” This is a somewhat ambiguous statement; an Arabian horse of any strain may “descend” from horses of any other strain if they are not in its direct female line. If this statement refers to the strain-determining dam line, it runs counter to the conventional descriptions of strain evolution, in which the other strains are said to arise from, and originally to be named as substrains of, the Kehilan Ajuz. Furthermore, strain designations are not expected to change in this way over the course of a few years (from 1924 to 1932) and outside the tribal breeding system.

Prince Mohammed Ali puts more emphasis on the fact that BINT YAMAMA “is a descendant of the stables of Ali Pasha Sherif, who bought his horses from my grandfather Prince Ilhami, son of Abbas Pasha I… the strain of these horses is in our family since 80 years…” It may not be reading too much into this to suggest the Prince is telling General Dickinson that, whatever their strain name, the origin of this family is unimpeachable. On the record which survives, Lady Anne Blunt’s efforts to record precise pedigree relationships among her Arabians of Ali Pasha Sherif origins may have been the exception rather than the rule. More often her contemporaries appear to have accepted a horse of named strain, “of Ali Pasha Sherif” or “from the stud of Ali Pasha Sherif,” as sufficient, and indeed unsurpassable, provenance.

The Prince added in the same letter that the stud records of his brother Abbas Hilmi II had been confiscated at the time the latter went into exile. While these records may well languish yet in some British archive, there has to date been no suggestion that they were ever recovered. If Prince Mohammed Ali changed his mind about the strain designation of this line of horses, his decision clearly was not based on information from his brother’s stud records. Still less can any subsequent ideas about the BINT YAMAMA pedigree have been based on the relevant stud records.

Preservation and Improvement

Breeders can have both in their programs

by Michael Bowling, Copyright © 1997

from Arabian Visions magazine Sept/Oct 1997

used by permission of Michael Bowling

I sometimes wish we had waited a bit longer in the preservation breeding community and used the terminology which has been developed by the American Livestock Breeds Conservancy: ALBC refers to conserving breeds or genetic stocks, while they limit preservation to technological innovations such as cryopreservation of gametes and embryos. This might be a little easier to understand in terms of everyday language. It’s too late to change now that “preservation breeding” is an accepted term, though it’s still useful to remember that distinction: frozen semen preserves genetic contributions from individual sires. Breeding from their descendants does not constrain the individual ancestors’ genetic representation in the same way.

ALBC also distinguishes groups which have been subject to selection in the past from those (land races and feral stocks) whose value is precisely that they have not been influenced by much if any human control over breeding. Animals in the latter class have had a chance to retain ancient genes for things like prolificacy, or resistance to weather, diseases, and parasites, and should continue to be bred with as little selective pressure as possible for visual or production traits. Some maintain that, in order to allow natural selection to operate, such stocks should also be raised without worming, immunizations, foot care, and the like.

The modern “straight desert” programs, with which I am familiar only in the most general terms, may define an Arabian preservation movement which is very close to the land race model–in theory, and I daresay largely in practice, their foundation stock was at least close to horses which had been selected primarily for survival under desert conditions, not in terms of any show ring visual standard.

Most of us are working in traditions which have been highly selected in the past; what we are preserving is, as much as anything, a set of minority views of what the Arabian horse is about. This is quite in keeping with the relevant population genetics theory as it’s very well presented by ALBC [see A Conservation Breeding Handbook, reviewed in the January-February 1996 Arabian Visions]: the goal is to maintain selection as nearly as possible to the same standards employed by the historical breeders of each tradition. Most of the people I know and work with (I realize there are other people active in other preservation contexts who may see things differently) are acutely aware that, in a narrow breeding group, we run the risk of having difficulty in breeding away from faults of conformation, type, or disposition. We are just as acutely aware of the strengths and weaknesses of each individual as we are of the distinctive character which sets our animals off from the breed at large.

As to the notion sometimes encountered that preservation breeding is not compatible with selection for improvement or with breeding “quality horses,” I think there are two separate ideas here: we want to improve our individual animals, in the sense of breeding to combine more of the best features of our kind of horse in each individual. What we do not subscribe to is the conventional notion that one can “improve the breed,” which seems to mean, in practice, “make it look more like some other breed.” Most of us are breeding within specific pedigree limits precisely because in our experience they turn out specific kinds of good Arabian horses.

Questioning Breeding Myths in Light of Genetics

by Ann T. Bowling PhD ©1995
from CMK Record, SI/3: page 5/6 Fall, 1995
used by permission of Ann T. Bowling PhD.

“Breeders cannot change Mendelian genetics, nor the number of genes involved in traits, nor their linkage relationships. They cannot change the physiological interactions of gene products, but they can hope through selective mating to realize gene combinations that consistently result in high quality stock.”

BINT SAHARA was a legendary producer of champions (this one is ROYAL GREY). What was her secret? Pedigree? Genes? A magic nick? Some of the above with a touch of just plain luck? (Photo: Linda Sale-Paich)

Newcomers to horse breeding often look for pedigree formulas or hope to emulate a particular breeder’s program by using related stock. Unfortunately for novices, the truths of horse breeding are that many successful horse breeding judgments are in equal measure luck and intuition. Horse breeding is not as easy to fit to formulas as breeding for meat or milk production. Many of the highly valued traits of horses such as breed type or way-of-going are subjectively evaluated in show ring events. Winners may reflect the skills and show ring savvy of the trainer/handler, as much as the innate abilities of the horse. Some breeders can learn to predict to their satisfaction the approximate phenotype to expect from a selected mating because of their years of experience studying horses and their pedigrees, but their skill cannot always be taught to others and may not work with unfamiliar pedigrees.

Nicks

Horses considered to be of excellent quality often present a pattern of recurring pedigree elements. Breeders naturally seek to define pedigree formulas or “nicks” to design matings that will consistently replicate this quality. But breeding horses is not like following a recipe to make a cake. You cannot precisely measure or direct the ingredients (genes) of the pedigree mixture as you can the flour, sugar, chocolate, eggs and baking powder for a cake. You can construct pedigrees to look very similar on paper, but the individuals described by those pedigrees may be phenotypically (and genetically) quite different. Before seriously considering any breeding formula scheme it is essential that breeders understand the most basic lesson of genetics: each mating will produce a genetically different individual with a new combination of genes.

A certain nick is often expressed as cross of stallion A with stallion B — an obvious impossibility! Probably one source of this convention is that it is easier to become familiar with the characteristics of the offspring of stallions than mares because they usually have a greater number of foals. Another source is the perceived need to reduce complex pedigrees to an easily described summary. Breeding stallion A to daughters of stallion B (this would be the genetically correct description of some nick) may produce horses of a relatively consistent type compared with the rest of the breed. For mares of the next generation, the “magic” nick (stallion C) is again at the mercy of genetic mechanisms that assure genes are constantly reassorted with every individual and every generation. Some breeders are reluctant to introduce stallion C at all, preferring to continue with their A-B horses, breeding their A-B mares to A-B stallions. If a nick works, and it can appear to do so for some breeders, basic understanding of genetics tells us that it is seldom a long term, multi-generational proposition unless it is guided by an astute breeder that is making breeding decisions on individual characteristics, not merely the paper pedigrees.

Basing a program on champions

Novice breeders are often counseled to “start with a good mare.” This seems to be reasonable advice, but does not make it clear that the critical point is to learn to recognize a good mare. Sometimes breeders fail to produce a foal that matches the quality of its excellent dam, while less impressive mares in other programs produce successfully. Probably the lack of objective criteria to evaluate horses accounts for both observations. A “good mare” need not be a champion, and a champion is not guaranteed by dint of show ribbons to be a “good mare.” As well, we do not know the inheritance patterns of highly valued traits for show ring excellence. If the ideal type is generated by heterozygosity (for example, the ever useful example of palomino), the only infallible way to produce foals that meet the criterion of excellence (palomino color) is to use parents of less desirable type (chestnuts bred to cremellos). This example is not to be taken as a general license to use horses of inferior quality, but to provoke critical thinking about the adequacy of general breeding formulas to guide specific programs.

Other breeders pride themselves in structuring programs based on using exceptional stallions. However, breeders should be aware of the fallacy of this type of strategy: “I like stallion Y but I can’t afford the risk to breed my mare to an unknown stallion like Y — I can only breed to a National Champion like Z.” Any breeding is at risk to produce a less than perfect foal, but the advertising hyperbole leads novices to think that certain avenues are practically foolproof. Included in the best thought out breeding plans must be an appreciation of the ever-present potential of deleterious genes being included with those highly prized. It is irresponsible to assume that an animal is without undesirable genes. The wise breeder understands the task as minimizing the risk of creating a foal with serious defects and maximizing the chances of producing an example of excellence.

A master breeder needs several generations (generation interval of horses is estimated to be 9-11 years) to create a pool of stock that contains the genetic elements that he or she considers important for the program vision. To learn to identify essential characteristics, a breeder needs to evaluate the horses and their pedigrees, not advertisements or pictures. When a breeder discovers those elements, he or she can make empirical judgments and is on obvious path for making good breeding decisions.

The cult of the dominant sire

In some circles, the highest praise of a breeding stallion is that he is a dominant sire. Another widely encountered livestock breeding term for an elite sire is prepotency. The implication is that all his foals are stamped with his likeness, regardless of what mare is used. This concept would appear to contradict the advice “start with a good mare.” Those owners who strongly believe in the strengths and qualities of their breeding females would surely question the value of a so-called dominant sire who could seemingly obliterate valued characteristics that would be contributed by their mares. A good understanding of genetics should allow a breeder to put the proper frame of reference to terms such as dominance and prepotency as applied to breeding horses. Some animals transmit certain characteristics at a higher frequency than is generally encountered with other breeding animals. Coat color is always the conspicuous example. Any stallion whose offspring always or nearly always match his color is popularly described as a dominant sire. To be excruciatingly correct, for at least some of the effects being considered the genetic interaction is not dominance but epistasis and homozygosity. A stallion could be homozygous for gray, leopard spotting or tobiano, so that every foal, regardless of the color of the mare (with the possible exception of white), would have those traits. Homozygosity for color is not necessarily linked with transmission of genes for good hoof structure, bone alignment in front legs, shoulder angulation or other traits that may be desirable. Most conformation traits seem to be influenced by more than one gene. Some stallions may be exceptionally consistent sires of good conformational qualities, but it is unlikely that every foal will have these traits or that any stallion could be so characterized for more than a few traits. The balanced view is that a battery of stallions is needed to meet the particular genetic requirements of each of the various mares in the breed. No one stallion can be the perfect sire for every mare’s foal.

Using genetics to guide a program

If assays for genes important for program goals are available, the probability of obtaining foals with selected traits from specific breeding pairs can be predicted. For many horse coat colors, offspring colors can be predicted, but conformation and performance traits are not well enough defined for predictive values to be assigned. So little is known about the genetics of desirable traits, it is premature to suggest that any general technique of structuring pedigrees consistently produces either better or worse stock.

The important lessons to learn from genetics to use for horse breeding decisions may seem nebulous to those looking for easy “how-to” information. Yet an appreciation of how genes are inherited, the number of genes involved in the makeup of a horse, their variability within a breed and the inevitability of genetic trait reassortment with every individual in every generation will provide the critical foundation for sound breeding decisions.

With the current interest in genetics and the new technologies available for looking at genes at the molecular level, information about inherited traits of horses is likely to increase significantly in the next decade. Horse owners can help with the process in several ways, including communication with granting agencies about specific problems of interest to them, providing money to fund the research, and providing information and tissue samples to funded research studies. Horse breeders are eager to have sound genetic information and diagnostic tests to guide their programs and fortunately, the future looks very promising.

An excerpt, printed by permission of the publisher, from the forthcoming book Horse Genetics by Ann T. Bowling. Publication by CAB International is anticipated in early 1996.

Calculating Relatedness

by Ann T. Bowling PhD
©1995
from CMK Record Spring 1995 XI/2
used by permission of Ann Bowling

Offspring resemble their parents to varying degrees, but the proportional genetic contribution of each parent is constant: half the genes of an offspring come from the sire and half from the dam. A relatedness coefficient of 50% or 0.5 is assigned to the parent-offspring relationship.

Full siblings on average share 50% of their genes, based on the likelihood that 25% of the time they will have received the same genes from their dam and 25% of the time they will have received the same genes from their sire. It is possible, with a very small likelihood, that full siblings may have either no genes in common or all genes in common. The random assortment of chromosomes during gamete formation means that we cannot predict the exact proportion of genes that any two full siblings have in common; we can only provide an average value for full siblings as a group. In practical terms, stallion advertisements to the contrary, one cannot assume that a full brother to a proven sire will be an equally successful breeding horse.

Half-siblings on average share 25% of their genes, and first cousins share 12.5%. More complicated relationships can easily be calculated. In the simplest of pedigrees evaluations, breeders may talk of “percentage of blood.” Of course blood is not the vehicle of inheritance, but is used in this context to imply genetic traits. These calculations provide the most probable proportion by source for an individual’s genes by summing the relatedness coefficients for every occurrence of a particular ancestor in a pedigree. The relatedness decreases by half with each succeeding generation (Figure 1). The sum is not an exact proportion, but a statement of the most likely percentage. It is always possible that the true genetic proportion in common could be larger or smaller than that calculated as a relatedness coefficient.

SAHAB Kawkab: 50% Ibn Sherara: 25% Sottam: 12.5% Sueyd: 6.25%
The Dahmah Nejiba of Khalil al-Hajry: 6.25%
Sherara: 12.5% A stallion of Ali Pasha Sherif: 6.25%
A Jellabieh of Ali Pasha Sherif: 6.25%
Bint Nura GSB: 25% Aziz:12.5% Harkan: 6.25%
Aziza: 6.25%
Bint Nura: 12.5% Zobeyni: 6.25%
Nura: 6.25%
Azz: 50% Ibn Nura: 25% Sottam: 12.5% Sueyd: 6.25%
The Dahmah Nejiba of Khalil al-Hajry: 6.25%
Bint Nura: 12.5% Zobeyni: 6.25%
Nura: 6.25%
Bint Azz: 25% Wazir: 12.5% Zobeyni: 6.25%
Ghazieh: 6.25%
Azz: 12.5% A stallion of Ali Pasha Sherif: 6.25%
The Dahmah Shahwaniah of Ibn Nakadan: 6.25%
Figure 1: The pedigree of SAHAB (see lead article, “The Banat Nura of Ali Pasha Sherif“) exemplifies the fraction of an individual’s genes most likely to come from each ancestor, presented in a conventional pedigree format. On average, a foal with this pedigree was likely to have received 25% of its genes from BINT NURA (shown in bold face); in fact SAHAB may have received more or less than that proportion.

See Also:

Preservation Breeding and Population Genetics

by Michael Bowling © 1995
from CMK Record XI/2 Spring ’95

(This discussion is based on outline notes for the talk I gave at the 1994 Annual Meeting of the Arabian Horse Historians Association. The timeliness of the topic is underscored by a comment from the outgoing AHHA president, Carol Schulz, that at least 90% of the Arabian foals registered in the last several stud books are of generalized “show horse” lines, representing no particular breeding direction or identity. This does not say anything against the show horses, but makes it clear that all other aspects of the Arabian horse–and that includes straight Polish, Egyptian, Russian and Spanish–must be divided among less than 10% of current US breeding activity.)

AZZ (Ibn Nura x Bint Azz), shown here with Lady Anne Blunt, was the last of her line. Lady Anne sent the mare to England in the vain hope that more sophisticated veterinary care might preserve this branch of Dahman Shahwan. (NBGS)

What do we actually mean when we talk about “preserving” a genetic stock? The object of the exercise is not simply, or even chiefly, keeping names in pedigrees; pedigrees are merely a tool which may aid in evaluating the structure of a breeding group. It is obviously possible to breed in a preservationist sense with stocks that don’t even have recorded pedigrees. It is also perfectly possible to have a name present in pedigrees, while no modern representative carries a gene from the individual in question.

The goal of preservation breeding is to keep in the world the traits, characters, hereditary factors which make one aspect of a breed or species different from another–in short, to preserve genes for the future. Preservation breeding carries the unspoken assumption that the “preserved” genes will benefit a larger population in future; defined breeding groups have value and identity in their own right, but in another sense they are being maintained for future use.

This brings us inescapably into the realm of population genetics: the aspect of the science of heredity which considers the behavior of genes over time, as affected by particular mating systems. Population genetics is a mathematical and highly theoretical discipline–frankly in graduate school I found it the least compelling aspect of genetics–until you have a real problem to which it applies, when the charts and equations suddenly take on life and meaning.

Much of population genetics theory is derived for the special case of “random mating”–defined as a situation in which every individual in a population has equal probability of mating with every other individual of opposite sex. Clearly this is an imaginary construct to simplify the math. Real-life matings are constrained by geography, finance, fashion, etc., any of which will lead to wide use of some lines or individuals, and neglect of others, and so directly to loss of genetic diversity.

Any individual horse standing before us is the product of its genetic makeup interacting with all the environmental factors it has encountered. Nutrition, training, medical care–all these come under the heading of “environment,” not just weather and soil conditions. Genetic diversity buffers the population against the effect of environmental change; it is what gives a breed the potential to respond to new conditions. Diversity includes the physical and mental traits of the traditional Arabian; “new conditions” in our context may include things like an increased appreciation of the traditional using and companion Arabian horse.

A breed is the sum total of all its individual horses. Historically the genetics and veterinary literature has treated members of breeds as if they were interchangeable average mathematical units. Fortunately with the recognition of genetic diversity as a positive good, an alternative approach is gaining currency. Preservation breeding emphasizes that a breed must not be viewed as the average of all its “random mating” individuals–in order to preserve we must identify and try to understand the differing strands of its makeup.

I have referred before to that useful metaphor of “the tapestry you are preserving.” One may “preserve” almost anything, from a near-perfect wall hanging which just needs to be cleaned and protected from future damage, down to a scrap of authentic thread which may be very useful for repair or reinforcement of a more complete but related fragment.

A static image of conservation or preservation could be misleading (any metaphor however useful is a comparison, not a description). We do need to remember that in Arabian horse terms there are no perfect tapestries, and clarify one difference between preservation breeding and other kinds of conservation (working with animals even differs from preserving rare plant stocks): Genes (DNA molecules) are essentially unchanged over the generations; individual horses are transient, ephemeral, fleeting combinations of genes. The tapestry image works so long as we keep in mind that the process is analogous, but the object of the process is quite different.

What classes of fragments might we conserve? All will be arbitrary, defined in some historical terms–“species” at least in the ideal is a natural, biological classification, but we are not working at the species level. Fortunately we can describe any group in biological terms once we’ve defined it.

  • Large closed groups: this is certainly the easiest category if you have one.
  • Large groups, with fuzzy edges: this has practical advantages but must be defined.
  • Small closed groups: working with these is challenging but possible.
  • “Endangered species”: this is where we run the greatest danger of “keeping a name in a pedigree” without any associated biological reality; small fragments are meaningful only if maintained in some relevant larger context.

Large closed groups: These are easy to define once we decide how large is “large”? Bottlenecks are relative, the more numbers we work with the better our chance of keeping a major proportion of the genetic variation we’re trying to save. We can describe a general picture here, and the other situations can be treated as they vary from it. This is where we need to introduce some population genetics concepts:

“Gene frequency”: a thing, a number, which tells us something about a breeding group; don’t worry about how to develop the actual number. All traits are based on genes, and all genes exist at some frequency–it’s just harder to measure the interesting ones so we sometimes use “markers.”

“Effective population size”: another informative number, which takes into account the relative breeding contributions of males and females. An effective population of 10 can retain genes existing at frequency of 0.1 or higher; uncommon (below 0.1) and rare (below 0.05) variants will likely be lost. For our purposes, in a typical horse-breeding situation, “effective size 10” means some number much larger than 10. Note: it does not matter whether the population expands in numbers; expansion helps to keep in circulation the genes that you do have, but it does not do anything about ones that were lost when the founders were selected.

“The sire is half the herd”–we all know that maxim. In a preservation breeding context the point is precisely that we don’t want any one sire to dominate any program to the extent of half its genes. The more one narrows down the sire selection, the more, and the more diverse, mares must be kept in order to retain the original genetic variation. The most efficient way to maintain diversity is to use multiple sires on several small sets of mares, and rotate the sires. The idea, always of course influenced by real-world considerations, among them the phenotypic suitability of a particular combination, is to equalize breeding opportunity in order to maximize the proportion of genes retained.

Inbreeding and selection pressure are considerations in any breeding situation–they are not specialized aspects of the preservationist approach. Inbreeding, like random mating, simplifies the math, so is overly important in population genetics theory. Inbreeding can be a useful tool, and incidentally is a fact in any closed breeding group–inbreeding operates at the level of breeds, so long as they have closed stud books, not just within limited subsets of breeds. Inbreeding drives genes to fixation and can lead to the loss of alleles from the population, so one goal of presevationist planning should be to minimize the average degree of inbreeding. Inbreeding is not an end in itself.

Once we have a preservation group defined (say for now all the horses, or at least a representative sample, are in preservationist hands, though that is not a trivial assumption) and reproducing, the best way to retain maximum genetic diversity is to spread the horses among more than one program, and let subgroups happen. In theory we want a set of “cooperator breeders” working toward a shared vision. That calls to mind another non-trivial problem: preservation breeders as people will, by definition, be eccentric and… let’s say independent minded. Those independent visions are essential, each maintaining its own distinct sample of the horses in question; there still must be enough of the shared vision, and some sort of working definition, to retain the genetic identity of the preserved group.

Part II (CMK Record, XI/3 Fall, 1995)

(Continued from last issue — the “to be continued” text block was lost in production. Last time we outlined the basic notions of population genetics, in terms of preservation breeding with a large closed population. Further implications arise when other kinds of genetic entities are to be preserved.)

Large blurry groups will maximize the contribution from the founder animals. Generally, by the time any breeding group needs attention at the preservation level, the genetic influence of many founders will be lost among those descendants which qualify for inclusion in a closed group. Whether through attrition of numbers, or use in outcross programs, or most likely both, any set of “straight” pedigree horses carries only a fraction of the founders’ genes–compare, for example, the original Blunt or Davenport array, with the sample of those influences represented in modern straight Blunt or straight Davenport breeding.

Gene frequencies among the surviving descendants of anything reflect the action of mutation (negligible over human time scales), chance and selection. The gene frequencies of any modern closed group likely will be very different from the frequencies that would have been calculated among the founders. This effect is apt to be less exaggerated (simply because more of the founders are represented) if we define our modern population so that it descends “largely” (deliberately vague) from those founders. To follow up the previous example, there are Blunt and Davenport genes in modern CMK Arabians which have been lost from their straight Blunt or Davenport relatives.

Philosophically and historically the breeding group with blurry outlines is different from more traditional approaches but it is squarely based on an accurate biological view: species are naturally distinct biological entities with more or less firm barriers against crossing; breeds are artificially maintained subsets of a species. “Breed” is a historical (originally geographic) concept, and acquires biological reality only after the fact; this cannot be overstressed. “Breed” and “species” do not have equivalent implications, in terms of original or maintained genetic differences. In evolutionary terms, the genetic distance between pairs of species is measured by comparing their relative frequencies for marker genes–in making such measurements researchers do not expect to find complete non-overlap between related species. Obviously then this will not be expected between breeds, leave alone subsets of a breed.

Working with a blurry edged pedigree definition is not the same as maintaining a closed group, and not a substitute where the closed group still exists–the two approaches are complementary. In setting up a blurry group its organizers must neither claim that it is something else, nor allow it to be thought less than it is in its own right. There must be a working definition which sets off a biologically and phenotypically distinct entity from the breed at large.

Few (if any) absolute genetic differences exist between breeds. Still less can there be absolute differences between subsets of a breed, and there simply is no way to tell what caused such differences anyway–they are every bit as likely to have arisen through chance loss of genes from one set but not from the other, as they are to reflect an original difference. Given they were shown to represent an original difference, such still could represent accidents of sampling the original population (in our case the Bedouin horses, which ranged over a large area geographically and were more or less separated in terms of tribal origins).

Working with a blurry-edged definition gives tremendous possibilities in terms of developing subgroups: founder genes of different origin (in Arabian terms, different desert samples) will get together and produce new combinations not existing in the original animals. This may suit a particular breeder’s approach admirably, while it strikes another as highly undesirable. Neither response to this biological fact is “wrong,” but this does underline that one must be aware that gene combinations are not static, even in a closed group.

Preservation breeding of livestock is not like working with, say, historical rose varieties. Modern bushes of a rose bred in 1830 are biological clones of the same plant, with exactly the same gene combinations as the ancestor (barring rare mutations). Modern descendants of an individual Arabian horse which lived in 1830 need not actually carry any of its genes, and they certainly carry those genes in different combinations than did that ancestor. To give a simple coat color example from a more recent individual, Skowronek was homozygous for grey and heterozygous for the black and red pigment genes at extension locus. There are modern chestnut Arabians of intense Skowronek breeding–horses bred to maintain a high relationship to this ancestor have lost three (at least) of his detectable genes at these two easily defined loci.

Small closed groups make for the most difficult and challenging and certainly the most intellectually fascinating kind of project. We have already acknowledged that large groups will develop subgroups. Over time these may be selected or defined into their own distinct existence, so eventually the “small group” scenario becomes a concern in almost any preservation breeding context, regardless of your starting level. Keeping to our original examples, the Davenport program is developing an elaborate substructure, and within the English descended aspect of CMK there are a number of possible distinctions, including straight Blunt, Skowronek-Blunt, straight Crabbet, GSB-eligible, Crabbet-Old English, and CMK of high Crabbet percentage. Each of these may be maintained in its own distinctive form, while individuals of the more specialized groups may contribute genes to the more general ones.

The narrowly defined groups exist in their own right but they also serve as a resource of mental and conformation traits, soundness and performance ability, for use in other contexts. This is quite analogous to the position of preservation-bred stock relative to the breed at large. The drawback, at least in theory, to maintaining the maximum number of small sub-groups, is that inbreeding within each subgroup will increase more rapidly than it would if the entire set of horses had been crossed freely among themselves. The other side of the same coin is that crossing sub-groups will later provide a way to increase heterozygosity, and theoretically vigor and fertility, without going outside the original closed definition.

The notion to take home here is that maintaining population substructure is an efficient way to maintain genetic diversity; the modern Thoroughbred, with its history of international exchanges of sires and overall genetic homogenization, possesses far less genetic diversity than does the Arabian, with its history of breeding in national or smaller subgroups.

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. Is this what you want?

A program cannot possibly maintain the full range of genetic diversity, and is not likely to maintain representative frequencies, of any founder population, through a bottleneck of two or three or five individuals. “Rare” genes are defined to exist below 0.05 frequency–nothing in a group of five horses (among them possessing a theoretical maximum total of 10 genes at any locus, and in practice there will be fewer) can exist below 0.10. If a “rare” gene from the original population, of which these five horses are a sample, is by chance present, it automatically has gone above its original frequency; if it’s not in there it never can come back, so long as the group is bred closed. This effect is not automatically either good or bad, but is simply what happens, and it illustrates that “preservation” operates at different levels. Clearly one can only “preserve” what is still in the world to be worked with, but just as clearly, the more extensive the sample with which one starts breeding now, the more correctly the desired population will be reflected in future generations.

A program cannot achieve flat phenotypic “uniformity” without losing genes; selection for a totally uniform true-breeding group is in fact the opposite of genetic preservation (besides being a highly theoretical construct–biological reality is quite different). A program, or a group of cooperator programs, can maintain or reproduce something closer to the original population by crossing derived lines back together. Sublines will automatically develop when more than one breeder is directing the course of selection, and so far from being disadvantageous, these can be highly useful from many viewpoints. (I am deliberately running this idea into the ground–it is one of the most important things of which preservation breeders must be aware.)

Endangered Species: At this level (“threads and fragments” in our tapestry analogy) a real genetic presence can readily be reduced to “a name in a pedigree” unless the line is maintained in some appropriate biological context. When a breed is evolving rapidly, saving descendants of an uncommon element means nothing, unless the breeder interested in preserving that element is working with some semblance of the breeding background to which it belongs historically and genetically. This point is missed by many people who breed horses–perhaps especially Arabian horses–who boast they have a line to Mare X or Great Sire Y but haven’t noticed (or alternatively may be quite proud of) how often the descendant bears little resemblance to the ancestor. No one would try to deny that such resemblances can persist across a breed–but the point of preservation is precisely that more such resemblances may be more predictably maintained if breeders don’t depend simply on chance to bring them forward. Chance will tend to swamp the real genetic influence of rare lines, by simple force of numbers, outside the preservation context. [See Ann T. Bowling’s “Questioning breeding myths in light of genetics“]

Sire lines tend to be the most rapidly evolving aspect of any breed of any species, except where a closed stud book has been essentially taken over by a line or two and there’s no more room for change. The Y chromosome is a biological entity and is only handed on from sire to son. It is possible to measure genetic distance by sequencing yDNA. Probably more important for our discussion, old and traditional sire lines are more likely to be maintained in old and traditional breeding contexts; the persistence of a no longer fashionable sire line is an obvious marker for the program directed by a breeder who appreciates the traditional stock. Emphasis on sire lines works both ways then–it definitely helps us to find genes of diminishing frequency, and it theoretically carries them physically (but remember few genes on the Y are known, except those directly relating to male fertility). [NB: to date (2007), while Y chromosome variation is easily found in most species tested, none has been detected in the horse.]

Dam lines tend to be biologically conservative. Rare and uncommon genes tend to be carried through the bottom of the pedigree–simply because so many more mares than stallions breed actively in each generation. By simple chance, more carriers of any uncommon gene will be used on the female side than on the male. Occasionally a mare will hand a rare gene on to one or more influential stallion sons and a breed experiences a major change in gene frequency. Mitochondrial DNA (mtDNA) is associated with the cytoplasm, not the cell nucleus, and thus transmitted almost entirely through the egg, essentially only through the female line. Very little mtDNA is carried by sperm (though such transmission has proven detectable in carefully designed mouse experiments). [See M. Bowling’s 1998 article “What’s in a Name“] [NB: it has been shown since this writing that sperm transmission of mtDNA does not occur under normal conditions.]

mtDNA carries important genes which interact with nuclear genes; also, like yDNA [which has not proven to be informative in the horse], it can be a tracer for historical and biological change and the interrelationships of lines. Generally populations have more dam than sire lines so mtDNA theoretically is more useful than yDNA; it has also proven more variable in practice. This area is only beginning to be investigated in the horse but it carries exciting potential.

“Middle of the pedigree” elements may readily be overlooked. Historically breeders have thought in terms of sire (west) or dam (east) lines–we often study published charts of sire and dam lines as a shorthand way of handling pedigrees. Sire and dam lines in fact reflect the smallest portion of any pedigree, and certainly of gene transmission–only the Y chromosome and cytoplasmic mtDNA respectively are guaranteed to run along the top or bottom of a pedigree. Except in terms of those two elements, and thus for the vast majority of genetic material, position in the pedigree has nothing to do with potential genetic influence; important horses, still visibly influential, may not have left direct sire or dam lines. Davenport’s *Haleb and the Blunt’s Bint Nura GSB come readily to mind as examples.

This opens an enormous area for discussion or consideration, and space forbids addressing it in more than this very elementary fashion. The underlying reality is that any ancestor in any pedigree may have contributed genes to any modern descendant–but at the same time any ancestor’s genes, once we get back a few generations, may have been lost completely. There is no way to tell by looking at the list of names which is a pedigree, the ancestors that actually are genetically important in the horse to which that list belongs. We must look at the horses and learn as much as possible about the ancestors, in order to make rational judgments on this point.

Mid-pedigree names may become important in developing subgroups. Simply as a fact–with neither negative nor positive associations–breeders may use any name as a marker to define a group (and it may be used by its presence or absence). The bigger and more influential the “name,” in fact, the more useful it may be, in terms of future genetic balance, to reserve some lines for crossing back to it–within the large group however defined.

What are we trying to preserve? Genetic diversity buffers the breed against change; genetic diversity interacts with environment to provide the basis for all variation within a breed. Preservationist breeders have one underlying goal: to promote the maintenance of genetic diversity. It should not be necessary to state that the preservationist approach grows out of having observed negative changes in the breed. We are preserving the genes which influence major traits, including disposition, soundness and endurance, which are not necessarily addressed in the show ring.

Different preservationist groups have more in common than they do dividing them; it is to all our benefits to make common cause for a generally different approach to breeding the Arabian horse. A listing of preservationist group contacts would be a very useful practical tool in advancing this goal, and the members of the Arabian Horse Historians Association, assembled at their 1994 Annual Meeting, agreed that serving as the clearing house for such information was a valid role for AHHA. Preservation breeders may themselves become an endangered species–no one has any choice without a vigorous preservationist movement.

from: “For the Record” CMK Record, XI/3: page 10/12 Fall, 1995

(GMB–We’ve edited Deborah’s letter because as we understand her point it’s not so much to comment on other preservationist activities, as to caution CMK breeders about mistakes they might be in danger of making. Of course we suspect, too, Deborah would agree if we pointed out that there are many registered Arabians which are not preservationist-bred in any sense, but which also “should not be bred on” for their lacks with regard to conformation, soundness, disposition or breed character. Overall we certainly second her warning and are glad to see such thinking in the CMK ranks: this movement absolutely would lose its identity, its purpose and its point if it did not continue to turn out the beautiful, traditional using Arabian that brought all of us into the CMK circle. Fortunately it is clear that CMK pedigrees continue to produce just that kind of Arabian. We have thought about this quite a lot, over the years, and it strikes us that CMK breeders in particular are not so much in danger of full-blown “preservationist syndrome” as may be the followers of some other lines of breeding. It is easy to be caught up in enthusiasm over the rarity of a particular individual, and obviously we all have our own preferences for some style of horse as opposed to another. That said, very few of us began in CMK Arabians with the idea first and looked for the horses later; a more typical CMK story is learning to appreciate a particular kind of Arabian–we would say practically always starting from a using, riding horse orientation–and then finding that “our kind of horse” belongs with the CMK Heritage. Other major advantages to CMK as a preservation scheme are its avoiding a closed definition and the great genetic diversity it maintains. Large-sense CMK breeders have much more room to operate than do the people working with other narrow closed preservation groups; specialized narrower groups within CMK may be crossed with other CMK lines without losing their CMK identity.

As the CMK preservation movement explores more kinds of promotional efforts, we can expect to hear from more people who actually do set out to see what these CMK horses are about, with no preconceived idea of what kind of horse they’re going to find. That is precisely why we need to go cautiously on the promotion front: we must be sure we are attracting people who can understand and appreciate this kind of horse, rather than those who may latch on to the name yet expect to modify the horses to suit some other set of criteria.

Deborah may not have had this next point in mind but many horse activities pursued these days do not place very high priority on the well-being of the horse, whether physical or psychological [the two are very closely intertwined]. [See Rick Synowski’s article “Post-Traumatic Stress Disorder In Arabian Horses“.] No thinking breeder would care to see any horse exposed to such dangers, but we are convinced the CMK Arabian in particular is ill served by certain aspects of modern training and presentation [and statements by show trainers bear this out]. The CMK Heritage will place more emphasis in future on the actual physical “preservation” of individual horses in this day-to-day safety sense. This must include, almost by definition, the encouragement of alternative systems of use and presentation which do maintain horsemanlike values and do emphasize the well-being of the animal.

We find, too, we can’t close without attempting to give a slightly different slant on “preservationist syndrome.” The American Livestock Breeds Conservancy distinguishes conservation–the simple maintenance of a stock in existence, without changing it–from improvement, breeding with selection toward any set of visual and functional standards. ALBC advises conservation of very primitive breeding groups, whose raison d’etre is to serve as a reservoir of basic genes for health and soundness which may be at risk for loss in high-performance domestic lines. By contrast selection for continued improvement is accounted appropriate in traditional “improved” stocks whose history includes a performance standard.

The using Arabians of the Reese and Dean circles, whose breeders provided the background for the CMK movement, certainly were highly selected. So were those of the Crabbet Stud. The breeders of the CMK Heritage can call on the genetic strength resulting from that selection; at the same time we have, as Deborah pointed out, a grave responsibility to maintain the standards which were achieved by those past breeders. The problem in modern Arabian horse circles, of course, is to recognize “improvement” when one sees it. There certainly are Arabian breeders who see any change that has come about since the horses left the Bedouin tribes as change for the worse, and who think in ALBC’s conservationist terms, of maintaining a comparatively primitive stock as little different as may be from the desert war mare. There are many more of us who are not impressed with the way the show horses have changed in this country over the past two decades [the wink of an eye compared to the breed’s history in the west, leave alone its prior existence]. There is a place for all of us, but it is essential that we understand the implications of our positions.

Do remember that many of the preservationist programs are operating with minuscule numbers of horses — all recognizable activity with an identity other than “mixed source show horse” amounts to little more than 10% of the breed combined. We address this not in terms of what level of selection a given program may have room to impose, if they are to breed any horses at all; but of the simple fact that their horses have relatively little impact on the 400,000+ living Arabians in North America. They cannot change the breed’s nature, and if such horses fill a place in their owners’ lives, that is really all that need be asked of them. There is nothing wrong with conservation breeding, in the ALBC sense, so long as one recognizes one is doing it, and does not make impossible claims for the results.

It’s a completely separate subject, of course, but we have never been comfortable with those overarching schemes one occasionally sees put forward, whereby some party or official entity is meant to “certify” breeding stock–not because we approve of breeding from poor horses, but because we cannot picture how any breed-wide selection scheme could be at once effective, in the sense of doing anything in particular, and sufficiently inclusive to recognize all the range of variation which the breed includes and which must be maintained for future reference.

As to the other-bashing of “preservationist syndrome,” we do consider it basic to be civil to one’s neighbors. In fact we always think it’s a pity when anyone with a preservationist slant doesn’t recognize that we are each other’s natural allies.)

[For more thoughts on this subject, see M.Bowling’s 1997 article “Preservation and Improvement.”]

See also:

CID: The Paradigm has Shifted

CID: The Paradigm Has Shifted

COPYRIGHT 1997 By MICHAEL BOWLING

from Arabian Visions magazine Sept/Oct 1997

used by permission of Michael Bowling

Author’s note: This piece illustrates the vitality of a new communications medium, for it grew primarily out of Internet discussions of the subject. Special thanks to Mary Anne Grimmell who planted the seed of “putting into laymen’s language” the potential uses and misuses of the new CID test, along with the positive impact it will have on breeding farms, large and small, and who assisted in reviewing the story in draft.

Everything you know about CID has to be re-examined in the light of a single new fact. It is now possible to know where the CID gene is. This changes the shape of our world. No CID foals ever need be produced again.

CID: PROGENY TESTING

Remember that progeny testing was previously the only way to know whether an Arabian horse had the CID gene. One could wait, and hope the gene did not turn up by accident; or one could make a systematic effort, and breed a stallion to known carrier mares, as one prominent breeder did with an imported horse a few years ago. (I am not aware that any other stallion was formally progeny tested, though there may have been one or two that I missed. Obviously if any horse had been so tested, and turned up negative, it would have been trumpeted from the housetops. Even at the highest estimates of CID gene frequency, most horses are expected to be negative; this implies that few were tested.)

To achieve 95% confidence of knowing an individual Arabian did not have the gene, one would have to see a) 11 healthy offspring from known carrier mates; or b) healthy inbred offspring from 22 of the tested animals’s own offspring. That awkward gender-free sentence is the only one I am going to have to write, since obviously no mare could ever be rigorously progeny tested to be CID-free, and also have a breeding career as such. Most Arabian stallions would end up siring more offspring in their progeny testing phase than they did in their breeding careers. (Note that breeding a prospective sire to 22 of his own daughters would have the advantage, over the 11 offspring from carrier mares, of potentially turning up any lethal or seriously deleterious gene(s), not just CID. Note also that it is 11 offspring from known carriers–which could include several offspring from any one carrier–but it is offspring from 22 different daughters.) That testing, to that level of confidence, has been prohibitively expensive — this is plain from the fact that essentially no one did it. And it would generate a whole crowd of young horses that needed to be somewhere, after the testing was done, whether the results were positive or negative.

CID can be openly discussed, because acknowledging one individual has the gene will no longer cast a pall over a whole breeding program or line of breeding. Individual horses can be tested and their individual status can be known; matings can be planned accordingly; guilt by association, and the notion of contagious genes, can finally be laid to rest. The rumor mill will have to find something else to grind. Statements of the form “Our neighbor’s daughter’s boyfriend’s cousin knew someone who bred a mare to that horse and had a CID foal” will no longer carry any weight (not that they should ever have done, but the climate of ideas will change, and the impossibility of proving a negative will no longer apply). The delusion that CID is the only lethal gene of concern in Arabian breeding can be put out of its misery as well, and the substantive discussion of other problems, and the search for other gene tests, can begin — inspired by the success with this difficult and challenging problem. The paradigm has shifted. New ways of thinking will be required.

A. What are the drawbacks to CID (or any lethal defect) without a gene test? I submit, the following:

  1. Foals die.
  2. Breeders suffer major emotional and financial hardship.
  3. Potential newcomers are put off becoming involved with the breed: at best they cannot be sure their new horses are not carriers, and they are at some risk of having known, but unadmitted, carriers foisted off on them.

B. What becomes of those drawbacks, given a carrier test? They all go away:

  1. No foals need die, because no one need unknowingly cross together two horses with the gene.
  2. Breeders can test their stock and know how to avoid the problem.
  3. Potential buyers can test their prospects and know where they stand. The paradigm shifts, and new ways of thinking are required.

For the frequency of a gene in a breed to be reduced, it is not necessary to remove from breeding all individuals possessing it. Such animals need only sire or produce fewer offspring than they would have done under random mating (if their status had not been known, in other words). That is almost certainly what will happen once this gene test is in widespread operation, and the gene’s frequency in the breed will gradually decrease. The benefits of the test therefore can be obtained without gelding all gene-positive colts, or denying registration to all gene-positives, or any other such scheme; therefore to do so would be an injustice. It would be applying the test to punish “a moral flaw,” rather than as a tool to manage “a gene” for the benefit of the breed. Genes do not have moral or ethical content; questions of right and wrong arise in the way humans deal with their knowledge.

Every individual of every species carries genetic defects, and CID is not the only lethal operating in the Arabian breed. Acknowledging the existence of a problem, and developing a rational means to deal with it, is the opposite of denying that it is a serious one. All the drawbacks of CID arose out of the fact that we could not tell where the gene was. Now we can. Vicki Hearne’s Adam’s Task, a book of long essays on animal training, describes human-animal interaction as a form of language. One of Hearne’s recurring themes is “the stories we know” about animals, or about the ways humans interact with animals, or the way animals interact with humans (she refers to animals as “knowing stories” too). Her position is that we can operate only in terms of the stories we tell ourselves, because that is the practical form our knowledge takes.

CID: COMBINED IMMUNODEFIENCY

The genetic immuno-deficiencies are a complex set of conditions; since the early 1950s close to 20 different syndromes have been reported in humans and examples have been recorded in a few other species. The first indications of what came to be recognized as severe combined immunodeficiency (SCID) of Arabian foals were clinical reports out of Australia in the 1960s, and the syndrome was described in the U.S. in 1973. Its inheritance as a simple autosomal recessive was established by 1977. The disease can be tentatively diagnosed from a blood sample of a young foal. A white blood cell (lymphocyte) count of less than 1000 per mm3 (vs 2500-3000 for a healthy foal) and lack of IgM (immunoglobulin M) are presumptive evidence of SCID; confirmation is by post-mortem showing underdeveloped thymus and lymph nodes. Lacking immune capacity, such foals will succumb before 5 months of age of massive infections.

With the SCID gene test:

  • Sick Arabian foals of untested parents can be tested for the presence of the SCID gene in double dose, which will provide rapid and definite distinction between foals which are candidates for major supportive efforts and those which are not.
  • Mare owners considering outside stallions for prospective matings can ask to see evidence of SCID gene status, and make informed breeding decisions.
  • Within a breeding program, excellent individuals which happen to possess the SCID gene may be bred so as to retain their good qualities and yet avoid producing affected foals, and gradually reduce the gene’s frequency.
  • It should be emphasized that SCID is a recessive genetic defect; no evidence has ever been found for any defect or weakness in heterozygous animals.

This notion has wide applications. For many years Arabian breeders told themselves the story that the Arabian, as “the oldest and purest breed of horse,” must by that nature be free of lethal defects. Many of them even extended this story to say that, if a lethal gene ever appeared, it must be the result of a pedigree flaw (not in the sense of introducing a gene from outside, but of somehow “causing” defects by violating the breed’s metaphysical purity). I recently commented to someone that Arabian horses have been held to be immune to the laws of biology; their genetic problems are viewed as the effects of past moral transgressions (this is a prominent theme in 19th century nature philosophy, and in early 20th century racism). The story of population genetics now tells us that lethal genes, like other genes, are part of a breed’s and a species’s history. Every individual of every species is now held to carry some lethal or highly deleterious gene(s) in hidden form. The longer a species has been under domestication, with matings controlled by humans and limited by studbook breed definitions, the more such genes will have a chance to arrive at substantial frequencies, and therefore to become unhidden through homozygous expression. In other words, the story that many Arabian breeders tell themselves, which amounts to saying that CID was a temporary aberration and if we can only get rid of that gene we will be “safe” again, is mis- (or dis-) information. There are candidate lethals described in the genetics or veterinary literature, some of which are better established than others (in terms of mode of inheritance, or the simple fact of being inherited; some are at present merely suspicious, since they appear to be recurring and breed-specific.).

The success of the CID story is that the gene now can become unhidden without killing foals. Our constructive response now is not to obsess over CID, which has been made harmless. It is to look for modes of inheritance, and for gene tests, which will put the other problems in the same position. People have been breeding blind with regard to CID for decades (its recessive nature has been known for over 20 years, never mind how long it existed before being defined). Now that situation has changed. With a gene test, CID is going to become a matter of fact. It will not be a whispers-behind-the-hand subject as it has been for so long. Some discussions of this topic seem to assume that the way things are (attitudes and assumptions, the stories we tell ourselves) are going to remain the way they are right now, forever. They will not. The paradigm has shifted. New ways of thinking are not only required, they are inevitable.

Selected References:

McGuire, T.C. and M.J. Poppie. 1973. Hypogammaglobulinemia and thymic hypoplasia in horses: A primary combined immunodeficiency disorder. Infection and Immunity 8: 272-277.

Poppie, M.J. and T.C. McGuire. 1977. Combined Immunodeficiency in foals of Arabian breeding: evaluation of mode of inheritance and estimation of prevalence of affected foals and carrier mares and stallions. J. Amer. Vet. Med. Assoc. 170: 31-33.

Shin, E.K., L.E. Perryman and K. Meek. 1997. A Kinase-Negative Mutation of DNA-PK (subscript CS) in Equine SCID Results in Defective Coding and Signal Joint Formation. J. Immunol. 158 (8): 3565-3569.

Studdert, M.J. 1978. Primary, Severe, Combined Immunodeficiency Disease of Arabian Foals. Austr. Vet. J. 54: 411-417.

Wiler, R., R. Leber, B.B. Moore, L.F. Van Dyk, L.E.Perryman and K. Meek. 1995. Equine severe combined immunodeficiency: A defect in V(D)J recombination and DNA-dependant protein kinase activity. Proc. Nat. Acad. Sci. US 92: 11485-11489.

A Look at DNA Testing

A Look at DNA Testing

copyright 1995 by Robert J. Cadranell from Arabian Visions Mar/Apr 1995 used by permission of RJ Cadranell  

        One topic much discussed in Arabian racing circles (and in all horse racing circles) is how to identify individual animals and make sure that their parentage has been recorded correctly. Arabian racing carries the added twist that surreptitiously introducing blood from another breed, the Thoroughbred, can give an advantage on the track.

        Tina (several people interviewed for this article are identified only by a first name, all of which have been changed) is actively involved with Arabian racing. “There is a widespread feeling that some of the horses on the track might not match their pedigrees,” she says. “People don’t want to get beaten by horses that are part Thoroughbred.”

        Niles grew up with horses, and has owned, raced, and bred Thoroughbreds for more than 20 years. “In the Thoroughbred world, when a record is broken, it’s usually by only a fraction of a second, not several seconds,” he points out. “Occasionally in Thoroughbreds we do turn up what we call a ‘sport,’ and these horses reproduce; St. Simon was one. But anyone who has studied the evolution of the Thoroughbred knows you can’t breed success overnight. And even in inbred Thoroughbred families, there is variance. So, sometimes I’m a little suspicious.”

        None of this makes Diane suspicious. She has owned Arabians for about ten years and is just starting to get involved with the sport of Arabian racing. “Arabian racing is still so new, anyone could turn up the next superhorse,” she contends. “Not all the bloodlines have even been raced yet. There are still far too many unknowns. It’s not like Thoroughbred racing, which has been going on for centuries. I think there’s a lot of talk that’s just gossip and sour grapes.”

        Likely much of it is more rumor than substance. Since the 1920s and earlier Arabian breeders have, from time to time, accused each other of having a Thoroughbred cross in their pedigrees. Most of these stories are probably nonsense. But there have been cases in the last 25 years of Arabian race horses turning in good times on the track and later having their papers canceled because bloodtyping did not qualify them to their purported parents.

        ”The Thoroughbred has been selected for more than 200 years for speed,” Niles says. “The proportion of fast twitch muscle is high. Arabians, on the other hand, have been selected over probably a much longer period of time for endurance: slow twitch muscle. Endurance racing records show the Arabians dominate the sport.”

        How long would a race have to be so the endurance of the Arabian would give it the advantage? Results from the Russian track give an indication. “Empirically it has been shown that only the Thoroughbred is faster than the Arab, but the latter is uncatchable at distances above thirty-five furlongs [4.4 miles].” (1)

        If racing enthusiasts are concerned about keeping things “clean,” would it work to race Arabians over distances long enough that there is no incentive to slip in an Anglo-Arab? “Absolutely not,” Tina answers. “The betting public will not sit through even a three mile race. It’s just too long. We’re struggling now to run on Thoroughbred tracks. The Thoroughbred people would laugh at us.”

        Niles agrees. “The public wants action,” he says. “Younger spectators are already complaining there is too much time between races and not enough excitement.”

        With Arabian racing fixed at the current distances, attention has turned to other means of verifying that everyone is playing by the rules. The problem of correctly identifying horses and their parentage is not unique to Arabian racing. Niles comments, “As a breeder, I don’t want to be dealing with an unknown factor. Thoroughbred racehorses can sell for $500,000 or more, and race for hundreds of thousands — even a million. We don’t want ringers. I have to know what I’m dealing with.”

        DNA testing has been a hot topic recently. Some registration authorities and labs are adding information obtained from DNA testing to the battery of data identifying individual horses. The Arabian Horse Registry’s application for a Racehorse Identification Supplement asks for, among other things, white markings and other identifying marks or scars, location of cowlicks, photographs of the animal, information on freeze marks and lip tattoos, and parentage qualification through bloodtyping.

        Since the 1970s, the Arabian Horse Registry has required that all breeding stallions have a bloodtype on record. Beginning with 1991 foals, all foals must be bloodtyped and parentage qualified to both sire and dam — which means all broodmares must now have bloodtypes on record before their foals can be registered.

        Only in recent decades has it been possible to verify parentage scientifically. For most of the history of the breed in America, the reliability of pedigrees has rested on the signatures of the owners. With thousands of people breeding, buying, and selling thousands of horses, mistakes can be made.

        An examination of Arabian Stud Book volume V, which covers breeding from the earliest registered American foal (born 1890) up to foals of 1944, turns up several horses with coat color incompatibilities: a grey with no grey parent, or a bay from two chestnut parents. There must be other foals registered with one or both parents recorded incorrectly, but without a coat color incompatibility to flag them.

        Cases of incorrectly recorded parentage might or might not involve a parent from another breed. One example is the 1938 grey gelding Zarab 1525, who has no registered progeny. Well known photographs of both his purported parents exist. They match the colors given in their registration entries; neither was grey. Photographs of Zarab in the Arabian Horse News and in the ranch brochure of his longtime owners show he definitely was grey. Coat color genetics exclude him as the offspring of his purported parents, Rifnas and Hazzadina.

        Does parentage verification by the currently available DNA test have a higher rate of efficacy than parentage verification by bloodtyping? “It’s close to a toss up,” says Dr. Ann Bowling of the lab at the University of California at Davis. “There really is not much difference between efficacy rates. DNA has the advantage that you don’t need blood, or even a live horse if other tissue exists. Bloodtyping’s advantage is that a huge worldwide database is already in place.”

        Could a DNA test be developed to reveal a cross of another breed one or two generations back? Ann Bowling points out that humans and chimpanzees have more than 99% of the same genes. Arabians and Thoroughbreds are far more closely related than humans and chimpanzees: if a horse has 100,000 genes, the Arabian and Thoroughbred may have as few as ten points of variance.

        ”Some of the markers in the Arabian breed do occur infrequently,” she says. “But are they from introgression, or from an under-represented desert source? If you go witch hunting for animals with rare factors, you could end up throwing out more Arabians of acceptable pedigree than you would cross breds.”

        In a recent article, Pepper Chastain of the Department of Animal Science at Texas A&M University makes a similar point. She says “Testing stringent enough to eliminate impure animals would also exclude 1 in 1000 legitimate Arabians from competition.” She also writes, “It is our belief that parentage verification (using DNA typing) at the time of registration is the only real solution for preserving the integrity of the Arabian breed.” (2)

        When asked if the Arabian Horse Registry of America (AHRA) would use DNA testing for parentage verification or as a way to determine “breed purity,” Registrar Ralph Clark responds, “Our only focus is on parentage verification. By multiple generations of parentage verification you don’t have a breed purity issue. The ISAG [International Society of Animal Genetics] agrees this is the only effective way to do this.”

        At the moment, he does not think there is any reason to replace blood typing with DNA testing. “I don’t see a significant advantage when you would have to retest all the horses. If bloodtyping can’t eliminate all but one sire, we will then use DNA — a test with no relationship and a separate efficacy. We feel we can approximate 100% efficacy using DNA as a second alternative.” Other drawbacks he mentioned include that there is yet no protocol for international standardization of DNA test results, and that the results have not been sufficiently tested in court. All that said, he did mention one advantage: “Hair root bulbs for a DNA test are much easier and less expensive to obtain than a blood sample.”

        The American Quarter Horse Association (AQHA) is embracing DNA testing as its preferred method for parentage verification, and is using the lab at Davis. Ralph Clark mentions a few reasons why a shift to DNA testing makes more sense for the AQHA than the AHRA. “They have not had a big bloodtyping program. For the most part, it involved just the major sires. Finally they had to address the question of whether to use bloodtypes or DNA. Converting would be a big problem in a couple of years — the number of animals involved is staggering.”

        The February, 1995 AHRA newsletter summarizes the Arabian Horse Registry’s position: “For the present, the Registry will continue to rely on equine blood typing as the primary means of verification of parentage. The Registry will also continue to monitor advances in equine DNA technology and standardization.”

1. Erika Schiele, The Arab Horse in Europe, p. 244.

2. Pepper Chastain, “Continued DNA Research,” Arabian Finish Line, December 1994, pp. 16-17.