In confinement, sexually frustrated stallions or donkey jacks will attempt to mate with cattle. The same goes for bulls when the only available partners are mares. Belief in the jumart hybrid goes back several centuries. According to Conrad Gesner, in “Conradi Gesneri medici Tigurini Historiae Animalium Lib. I de Quadrupedibus viviparis” (1551) (“Of Quadrupeds that Bear Live Young”) wrote, “I sometimes hear of a strange type of mule produced in France near to Grenoble. It is produced by a she-ass mated to a bull, and is called ‘jumart’ in French.”

In 18th century French folklore, it was believed that a bull could be mated to a female donkey (or more rarely a cow and a stallion) to produce a superior type of mule having the body of a horse, the head of a bovine, and hindquarters resembling those of a cow. According to the Oxford English Dictionary, Jumart (French) is derived from jumare, which is from Provencal gemerre or gemarre which are of uncertain origin. Alternatively, it is from “jument” (French for “mare”), from “iumentum,” (Latin for mule or beast of burden).

In the 1700s, jumarts (or kumrahs) were taken for granted as existing, but being less common than mules, although some naturalists (e.g. Buffon) expressed doubts. Relatively few ox-horse/ass mating resulted in offspring, and only the solid-hoofed offspring were useful as beasts of burden, any born cloven-hoofed were destroyed. According to Georg Simon Winter von Adlersflügel’s Stuterey (Stud Management) in 1703: “Keep the bull in a darkened stall, accustom him to wearing a rope halter and feed him well. Also rub him frequently with the same grooming powder used for stallions. Keep him this way for a few months, leading him about regularly by his halter (at night), and each day, use a sponge to rub him well under his nose with the scent of a mare in heat. Then, on a quiet night, lead him to the mare and make him cover her. We emphasise that this must be repeated until the mare conceives, at which time one need no longer lead him to her. In addition, place the mare in a ditch dug in the ground and restrain her head between posts so that the bull can easily mount her. One should also cover her head so that she will not see the bull.”

The Gentleman's Magazine, and Historical Chronicle, Volume 38, 1768. “Mr Urban, Notwithstanding your correspondent A.B.’s well known anatomical abilities; yet the following relations from authors of credit, seem to confirm Mr Baretti’s account of the Gimerro or jumart. Yours, L.S.
In Dr Shaw’s history of Algiers, p. 239 (chap. Of animals) he says, he observe the creature called the Kumrah, a little serviceable beast of burthen, begotten between a she-ass and a cow. It has no horns, and a hoof like and ass, but distinguished in all other respects from it, by having a sleeker skin, and a tail and head like a cow. Pere Merolla, in his voyage from Italy to Congo in Africa, put into the island of Corsica; they brought him an animal to carry his baggage between a bull and an ass. A Portugueze told him that such animals were common at Cabo Verde. The intention of this mixt breed was to procure a creature more expeditious than bull or ass. Dr Legers in his history of the Vaudois, printed anno 1669, observes that in the valleys of Piedmont are animals of a mixt breed called Jumarres. When engendered between a bull and a mare they are called Baf; when with a bull and a she-ass, they are called Bif. The Jumarres have no horns, [are] of the size of a mule, and are very swift. The doctor relates that he rode one of these animals 18 leagues, or 54 miles, on the 30th of September, all over the mountains. A great performance in so short a day.”

According to Buffon in 1771, “It is alleged that another kind of mule, called jumar in French, results from mating a bull with a mare. I brought one of these jumars from Dauphiné, Iand another from the Pyrenees, and by inspecting the outer parts and dissecting the inner parts I found that both of these alleged jumars were hinnies, that is, the offspring of a horse stallion and a she-ass. I therefore believe I am justified by my observations and by the lack of resemblance, in believing that this type of mule does not exist and that ‘jumar’ is just an imaginary name with no correspondence to a real creature. The nature of a bull is too different from that of a mare for them to produce offspring together: one has four stomachs, horns, and cloven hooves, while the other is hornless and solid-hoofed with only a single stomach. Their generative organs are very different both in size and in proportion, so there is no reason to think they could unite with pleasure, let alone with success.” However, in the Supplément à l’histoire des quadrupèdes, Buffon reported a bull that mated with a mare three or four times a day, with nor offspring resulting.

In 1815, Mr. de Villeneuve-Bargemont, prefect of the department of Lot-et-Garonne, member of the Society of Agriculture, Sciences and Arts of Agen, in his work "Travels in the Valley of Barcelonnette, Department of Basses-Alpes" the jumart is common in this region and is greatly appreciated because it combines the strength of the ox with the patience and sober nature of the donkey; it is born from mating a bull to a donkey which are locked up in the same stable at night." (Letter XII)]

In general, jumarts were mule-like, but had a cow-like dished face and the shanks of a cow, but the hooves of a horse (i.e. not cloven). They were of ordinary size, or slightly smaller than a mule. The coat type varied from sleek and ox-like to thick and rough like an ass. The main difference between jumarts and mules was said to be in the jumart’s shorter ears, rounder muzzle, short upper jaw and sharper backs. Where it was produced by a jackass or stallion mating with a cow, the jumart was said to lack upper incisors. Some of these traits suggest hinnies, while other features could be accounted for by the mismatch in genetic content unusual growth patterns. Looking at photos of a jumart skull a couple of things are evident. The maxilla (upper jaw) is abnormally short and the upper teeth are almost horizontal. Short maxilla is one form of macrognathia and can be hereditary, congenital or caused by birth trauma. Various chondrodysplasias cause the mid face to be under-developed. The nose to be flattened, the lower jaw to protrude and the forehead to be domed – giving the visual impression of a cow’s head. The domed forehead and abnormal eye sockets explain the “bony knobs” (or bosses) on the forehead, which early observers took for horn-buds. Chondrodysplasias are associated with dwarfism and this would explain the abnormal proportions and/or configuration of limb and limb joints. Supporting this is the fact that jumarts were described as slightly smaller than normal mules. A conformation fault in horses is known as “cow-hocked.”

The voice was said to be between the lowing of a cow and the whinny of a horse, but this could be linked to the abnormal development of the palate and, possibly, the larynx. Apart from those apparently ox-like features, a jumart apparently resembled its equine mother, and upon dissection, jumarts, like horses, but unlike cattle, lacked gall bladders.

What then of the appearance of cloven-hoofed hybrids? The ancestors of the modern horse had five digits which ultimately evolved into the single hoof we see today. Mutations or abnormal development sometimes produce horses with a central hoof and a with a vestigial digit on one or both sides of the hoof. This is a called polydactyly and one famous example is said to be “Bucephalus,” the steed of Alexander the Great. Bucephalus means “ox-headed” so perhaps he had a mild form of facial macrognathia. In any event, he was unusual enough to command the high price of 13 talents (312,000 Roman sesterces), but the ox-like head and vestigial side-hooves don’t mean that Bucephalus was a horse-ox hybrid.

AN ACCOUNT OF A MONSTROSITY, PARTAKING OF THE PECULIARITIES OF A COW AND HORSE By Mr. J. W. Gloag, V.S.
The Veterinarian, a Monthly Journal of Veterinary Science, Volume 3, 1830

About eighteen months since, I was at Greenwich, and my curiosity was excited upon hearing that a monstrosity was then exhibiting, partaking of the peculiarities of the cow and horse. The animal seemed to be about fifteen hands high (a mare, if I dare call her so), of the commonest description, and three years and a half old. The most striking peculiarities were in the tail, hips, head, breast and off [i.e., right] fore leg. The off fore leg, from its singularity, claimed my first attention; and I was induced to examine it with great care, as, at first sight, I suspected it might have been the result of disease. The shoulder-blade and the humerus seemed to be shorter and more upright than usual, and the latter bone was thicker, and turned very much outwards. This leg was in every respect similar to a cow’s; but the similarity was still more evident when I descended to the foot. There were two hoofs, with separate joints, and a natural [separation] between them. There was no sign of a frog, but the animal trod upon her heels, and used the foot precisely as a cow. I walked her round the stable several times, and it was really ludicrous to observe the difference in the manner of progression between the two legs. The colour of the hair on the body seemed to present a strange mixture between that of both animals; but it was long, soft, and loosely attached. The head had a very curious appearance: it seemed to be broad at the poll, and the ears were very large, and rounded, and turned backwards and inwards and covered with long, shaggy hair. The lower part of the face projected very much on each side, giving a width very dissimilar to the face of the horse. There were six incisor teeth in each jaw, but very unevenly distributed; and they seemed to partake much of the mixed character. The breast was wide and hung down, strongly resembling the dewlap. The body, neck, and near [i.e., left] fore leg, resembled those of the horse. The hips, tail, and [hind] legs above the hock, were exactly similar to those of a cow. The spinous and traverse process of the ileum projected very much, and the pubis stretched backwards, giving the great prominence of the bones of the ischium always so observable in a cow. The sacral processes did not project, and the tail did not arch over the pubis, as in the horse, but seemed to fall more abruptly: it was shaved nearly to its tip, where was left a tuft of hair, which was frizzled, and very like that of a cow. The tail felt very fleshy and at its base the skin was loosely attached; and the vagina was without colour, and hung down as in a cow. The patellae were very thick and large, and the hinder extremities, above the hock, were totally dissimilar to a horse. The mammae were not very large, nor was the udder unnaturally distended. At this time I related the facts to many veterinarians, among others to Mr. Sewell.

A short time since I called upon Mr. J. Skilt, V.S., at Southwark Bridge, and he informed me that he had seen the skeleton of a very strange animal at the knacker’s; and wished me to go and examine it with him. I did so; and was much surprised and pleased once more to have an opportunity of surveying the monstrosity I have just been describing; and I am enabled to add the following particulars to my previous description of her:—The occipital and pterygoid processes are large, and the former very broad and projecting, and differing from the triangular-shaped process in the horse. There are no signs of horns. Just above the three anterior molars on each side is a large projection, similar to specimens of disease wherein the teeth have still remained in their sockets. The three first molars are perfect cow’s teeth. The ileum and pubis are laid nearly flat, as in the cow. The number of ribs and vertebrae are the same as in a horse. All the joints seem to be unusually large. The greatest peculiarity is, however, in the off fore foot; and I am obliged to be very concise in my account of it. Articulating with the lower head of the large metacarpal bone is another, altogether shorter and broader than the large pastern of the horse, and cleft nearly to its middle; and, articulating with each division, are the remaining small bones of the foot. There are two hoofs, separately joined, with a natural [separation] between them; but they have grown enormously since I saw the animal alive. The knacker informed be that he did not perceive any thing in the stomach different from that of the horse. Any gentleman who wishes for more information can examine this, and many other curious specimens, at Winkley’s Yard, in Fryer’s Street, Borough. The only history I could learn of the animal was, that the owner had purchased her from the breeder, who stated, that her dam, when very old, had been put out on Finchley Common with a bull; that no horse could have access to her; and that this very singular animal was probably the offspring of the mare and the bull.

Bell's Weekly Messenger, 23rd June 1862: The following extract is actually a portion of a Bull-card seriously issued and at present in circulation. The district for whose use and benefit the notable production was designed is that of Pilling, a portion of the Fylde country, lying between Lancaster and Fleetwood. "A valuable opportunity to breeders of high prised (sic) cattle, and others who wish to improve their stock; that beautiful thorough-bred bull, King Tom, the property of John Bradshaw, Pilling, will serve cows this season at 10s. 6d. each. King Tom boasts of the blood of the Godolphin Arabian [a founding stallion behind thoroughbred racehorses], and the red polled Scot, from which all the pure and fashionable blood of the present day has derived its origin. This cross was brought about through the untiring efforts of Sir Charles Colling in 1717 (see Coates’ ‘Stud Book’), who certainly was the leader and surpassed all competitors in the improvement of Shorthorns.” Whether this incongruous and most extraordinary jumblement of words and ideas was written in sober earnest, or is the result of a jocose spirit bent upon amusement, we have no means of ascertaining, but that it is accepted by the whole region round about Pilling as a genuine and solemn announcement of indisputable facts is certain [. . .] Our readers may have heard of jumarts, or monsters resulting from the union of bull and a mare (Locke mentions them—in fact, he is the earliest English writer who uses the word jumart—and they are mentioned also incidentally in the Veterinarian, No. 3461, but this is probably the first intimation on record that the beautiful shorthorns of Great Britain descend from a horse and a hornless Scot.

SHORTHORN INTELLIGENCE. Bell's Weekly Messenger , 26th October 1863. It will probably be in the recollection of some at least of our readers, that upwards of twelve months ago we took occasion to mention jumarts, monsters said to be the result of a union between a bull and a mare. We named Locke as the earliest English writer who uses the word jumart, and referred to the Veterinarian (No. 346) for an incidental notice of the incongruous animal compound. The subject is alluded to in the following passage extracted from an agreeable review in the Times of October 7th [1863], of the Journals and Correspondence of Dr. Whalley, a divine well known in certain literary and fashionable circles both in London and Bath during the latter half of the last century. The circumstance occurred during a tour the Continent. “Another of Dr. Whalley’s curious experiences consisted in a ride on an extraordinary animal, of which, till we read his journal, we never heard the existence in zoology. Whether or not it was hoax we will not decide, but the editor asserts that the animal is described by a Moderator of the Vaudois Church in a scarce history, which was published in 1669, and that he himself, when he was formerly in the Vaudois valleys, found the animal was still known there. Dr. Whalley at first thought the beast in question was simply a mule, but as it differed in some particulars from a mule proper his curiosity was aroused, and he asked his attendant, who informed him that it was a jumarre — in other words, a cross between a bull and mare. The jumarre, if such he really was, proved an ill-conditioned brute, and, after biting and kicking at his companions by the way, pitched Dr. Whalley into a river, and made repeated efforts to finish him.”

On opening Locke again, we find that he speaks of jumarts “frequent in the world,” and illustrates the general subject of extraordinary progenies by a case which has the authority of the philosopher’s personal experience. “I once saw a creature that was the issue of cat and a rat, and had the plain marks of both upon it; wherein nature appeared to have followed the pattern of neither sort alone, but to have jumbled them together.” That Locke was very dupeable, the story of Prince Eugene’s Portuguese parrot sufficiently testifies. But he was a man of the most undoubtable veracity ; and being a man also of a keen and questioning mind, it would seem incredible that he had not ascertained whether the animal which so harmoniously combined such dissimilar and incompatible elements, was really, or was only said to be, the offspring of its reputed parents.

NATURAL HISTORY. The Cornishman, 3rd June 1880: The latest “evolution” is a French freak – the ‘Jumart,’ born of the coupling together of the bull and the she-ass, which they confine in the same stable, is common, and they appreciate it highly, because it unties the power of the ox to the patience and docility of the ass.

HOW DO YOU ACCOUNT FOR THIS? Keowee Courier (South Carolina), 22nd February, 1893: C. W. Hunt, of Mountain Rest, reports a curiosity, monstrosity, malformation or phenomena at his farm in the shape of a combination calf—half calf and half mule—which was born last week. Its feet are those of a mule, small and shapely, and have no sign of the calf’s cloven hoof. Its head and ears also are quite mulish, bearing a decidedly closer resemblance to a mule than a calf. The remainder of the body of the creature is that of a calf. At three days of age the little freak was alive, apparently healthy and gave every promise of growing to maturity.

HALF HORSE, HALF COW. Poverty Bay Herald (New Zealand) Herald 18th July, 1893: A cow recently gave birth to a pair of singular animals. They resemble colts more than calves, although both possess rudimentary horns and hoofs of cattle, but in all other respects they seem to be young horses, having long, flowing manes and tails of colts, only these latter are unusually long and bushy. One is a male and the other a female, and both are well-developed, well-shaped animals. The mother, however, seems to know that there is something abnormal about them, and has declined to allow them natural nourishment, so that they are to be brought up by hand. The mother is a young Jersey of unmixed breed and a valuable animal. As usual, the penny show proprietors have scented out the curiosities, and have proposed to purchase them, but the owner has declined, having a mind to watch the development of these singular offspring. The other cattle and horses on the farm alike refuse to consort with the strangers, and it has been found necessary to isolate them in a separate pasture. The colt-calves are playful little creatures, and seem to possess affectionate dispositions, coming to the bars at a whistle from the man having them in charge. Crowds from all over the country have been to see the curiosities.

WONDERFUL COW-HORSE. The Lindsborg news, Kansas, 2nd August 1901: Veterinarians are interested deeply in a freak cow-horse, which is in the possession of Mr. William S. Hugo of Elizabethport, N.J. At first glance the animal looks like a mare of natural size, but on approaching her hind quarters the formation of a cow is discovered in the hip bones, which are level with the backbone. She measures 23-and-a-half inches from one hip bone to the other. The mare has natural shoulders and head, but when traveling has the peculiar stride of the cow. The animal has attracted much attention, and several circus men have endeavored to buy her. The mare can get over the ground in lively fashion, while not appearing to be going fast. In the stall the animal chews her cud, as does a cow or bull, and if watched closely many of the attributes of the bovine can be observed. When swishing flies her motion is the same as that of a cow. She can gallop, but in a clumsy fashion only.

HALF CALF AND HALF MULE The Oakdale Leader, 23rd May 1902: A freak is reported from the ranch of R.F. Green, east of Lodi. It is part calf and part mule, apparently. The eyes and mouth resembles those of a mule colt [foal]. A mule’s ear appears where one horn should sprout, and the other side of the head in time will be ornamented with a horn. The two rear hoofs are cow-shaped, while the forward ones conform to the hoof of the mule colt. Its tail is inclined to be on the mule order, but it is about double the ordinary length. Probably the most striking feature of the little freak is its voice. The tone does not harmonize with the plaintive bawl of the calf, nor is there detected in it any of the “melody” or volume that belongs to the mule. The mother of the strange appearing offspring seems to understand everything it says and is a devotedly attentive as a cow could be. – Stockton Mail.

Worth reading: The Jumart or Cross between the Horse and the Cow - Conway Zirkle, Isis, Vol. 33, No. 4 (Dec., 1941), pp. 486-506

THE SUPPOSED STAG-PONY MARE HYBRID