NEWS
A roan by any other name is a roan
Posted: Saturday, May 04, 2002
Contrary to Jockey Club convention, gray and roan--not to mention white--are completely separate genes
True or false: In 1988, Winning Colors became the first roan to win the Kentucky Derby (G1). The answer is true because Winning Colors was registered as a roan by the Jockey Club. The answer is also false because Winning Colors was genetically a gray, not a roan.
In 1993, the Jockey Club introduced a new color category for registration purposes by combining two old categories. Henceforth, all horses that would previously have been registered as "gray" or "roan" would be registered under the umbrella of "gray or roan." This was all well and good except for the fact that, outside of Thoroughbred breeders, the rest of the horse world long has been aware that gray and roan are two unrelated color patterns controlled by two completely different genes.
Gray is a pattern of white hairs infiltrating a coat of any base color (bay, chestnut, brown, black, etc.), that steadily lightens with age. The gray gene progressively blocks pigmentation of the coat. Roan is identified as white hairs infiltrating any base coat color from birth but the overall effect does not lighten with age. The most important difference between the two is that, outside of seasonal coat changes, roan is nonfading, while the very nature of gray is the fading color. In other words, if the horse is turning white, it is due to the gray gene not the roan gene.
Therefore, it is easy to figure out that Winning Colors, who won the Kentucky Derby while she was still a pretty rose gray but who is now a silvery white, must therefore actually be a gray. Likewise, Vigors, Heavenly Cause, Al Hattab, and Geisha (dam of the great Native Dancer), all of whom were registered as roan, turned white with age and thus were, in actuality, grays.
In fact, it is safe to say that nearly all Thoroughbreds registered as roans in the last 60 years or so were actually grays. This has led to another sweeping generality that may also be untrue. There are those who argue that roan is not a valid color in the Thoroughbred and that the term should be thrown out of the registry altogether. While the term roan has been misused in its confusion with gray, there is evidence to indicate that some Thoroughbreds do carry genetics for roan color patterns. These horses do not display the classic or true roan patterns found in some other breeds such as the Quarter Horse, but they have roaning to some degree and seem to pass on this phenomenon to their offspring.
Different patterns, different genes
We have already given the description for roan, a nonfading mix of base color hairs with white hairs. This is the description that horsemen have used for centuries. But a deeper study into this color scheme reveals that there are different kinds of roaning patterns that are the result of different modifying genes. One might refer to a horse as spotted, although it may be either tobiano, overo, leopard Appaloosa, or dusted with Bend Or spots. These are all spotted patterns, but they are not spotted in the same way and are the result of different genes. Likewise, different genes can manifest the roan pattern in one form or another without the horse being a true roan in the genetic sense of carrying the Rn gene.
The true roan is often seen in Quarter Horses, some draft breeds, and a few other light horse breeds. These horses have the classic roan pattern, with the white hairs evenly distributed over most of the body but with the head and lower legs appearing darker because they are unaffected and so show the true coat color. This pattern is not seen in Thoroughbreds, but there are two other forms of roaning that can appear in Thoroughbreds in varying degrees.
One of these is called "sabino" and the other "rabicano." Sabinos are better known because they are harder to miss. The pattern is characterized by extensive white markings of the face and legs, usually with ragged borders, and often accompanied by some roaning on the flanks and belly. The sabino pattern is what makes the Clydesdales so flashy and is also popular among the Tennessee Walking Horse breed. In fact, many of the flashy strawberry roans in that breed are actually sabinos and not true roans.
In Thoroughbreds, horses carrying the sabino gene often have more than the average amount of white markings, and chestnuts also tend to be much flashier than bays. Northern Dancer carried the sabino gene, as evidenced by his own crooked blaze, snip and three white feet, and the many flashy chestnuts he sired, such as Vice Regent, Northern Taste, and The Minstrel. His granddam, Almahmoud, was a blazed-faced chestnut with stockings and is one of the most likely sources of the gene in his pedigree.
Sabino can manifest itself in varying degrees, perhaps reflecting an additive effect if a sabino gene comes from both parents. The top sprinter Time to Explode is a chestnut sabino with a blaze, high hindleg stockings, and a belly splash with some roaning on his barrel. A more radical version is the unraced Airdrie Apache (by Naevus-Not Quite White, by Northjet [Ire]), garishly splashed with white and red. He is a registered Thoroughbred, in fact registered as a chestnut, but he is also double registered with the American Paint Horse Association, because he is very nearly 50% white. Some of Airdrie Apache's offspring take sabino to the next level and are solid white, or nearly so, with blue or brown eyes (to distinguish them from albinos, which have pink eyes). In most cases, white Thoroughbreds are actually one big sabino-induced white marking.
Original sin
The other roaning variant, rabicano, shows up in Thoroughbreds and other breeds as white hairs or ticking mixed in their base coat, especially prominent along the flanks and in the hairs at the root of the tail. The roaning on the flanks can sometimes be extensive enough to create a vertical striping pattern along the ribs. The hairs at the base of the tail often appear as bars or rings, giving the coloration the name "coon tail" or "skunk tail." This explains the colorful name of a horse found in Volume 1 of the General Stud Book, the Ringtail Galloway, sired by Curwen's Bay Barb and out of an unnamed mare by Hip.
This rabicano coloring has popped up in some of the best of the breed. Cox's Ridge displayed this pattern in his bay coat, as did Slew City Slew, Doyoun, Bois Roussel, Pilate, Stedfast, St. Frusquin, Lesterlin, and Venison. The phenomenon in Thoroughbreds is better known as "Birdcatcher ticks," named for the famous stallion who displayed the same markings so vividly. Birdcatcher was foaled in 1833 and was a dark chestnut with a narrow blaze and a stocking on his right hind. A contemporary description of him notes that he was "chestnut, flanks ticked with gray hairs, a bunch of white hairs at the butt of his tail."
Yup, that's a rabicano. Birdcatcher was sired by Sir Hercules (1826), who was described as a black horse with silver hairs in his coat, especially his flanks and hindquarters, and at the root of his tail.
Digging through the first volume of the General Stud Book, the writer found at least 80 horses listed as roan. There did not seem to be the modern confusion between gray and roan; in fact, very few of these had gray parents. One of the earliest was a stallion referred to as Gresley's Bay Arabian, also known as Bay Roan. Apparently, this horse was a bay with some roan markings that were worth noting but not enough to describe as his base color.
Another was Miss Layton, also known as Lodge's Roan Mare (1731), by the flashy chestnut Partner out of a mare (color unknown) by The Cardigan Colt. This mare produced several roan offspring to the cover of the famous Regulus. There was a sister to Lodge's Roan Mare, who was also probably roan, since she appears as the dam of several roan offspring by Regulus and Cade, both bays. A third was the unnamed 1733 filly by Hip out of the Large Hartley Mare. Hip's color is unknown, but the Large Hartley Mare was chestnut.
Two more were Joan (1757) and her unnamed sister (1759), both by Regulus out of the mare Silvertail, by Whitenose (doubtless eponymously named). Both parents were said to be bay, but the dam's name reveals that she was probably also the owner of a tail with silver hairs in it, typical of a rabicano. It is worth noting that Silvertail's third dam was by Gresley's Bay Arabian (Bay Roan).
Bald but not hairless
The most remarkable thing about these early roans is the frequency with which the sires Regulus and Cade appear in their pedigrees. Even without those tracing back to the known roan mares noted above, the vast majority of the roans in Volume 1 of the General Stud Book have close and often multiple crosses of Regulus and Cade. Later in time, white hairs at the base of the tail were referred to as "Match'em arms" after Cade's son Matchem, who seems to have either displayed them himself or passed them on to his offspring.
Look closer at the pedigrees of Regulus and Cade. Both were sons of the Godolphin Arabian and out of mares by Bald Galloway. Bald Galloway was notably a brother to a mare named Points, who was the granddam of the Large Hartley Mare, a mare who was known to produce a roan foal.
Bald Galloway's color and markings are unknown, and his pedigree nearly so. He was by St. Victor's Barb (pedigree unknown) out of Grey Whynot, by Whynot (by Fenwick's Barb out of a Royal Mare), and his second dam was a Royal Mare. His name hints that he was a horse with a lot of white markings. In those days, the term bald was not used to refer to a lack of hair but instead, as we call a horse with a broad blaze "bald-faced," the term was used to describe excess white. The famous mare Bald Charlotte (1721) was a blazed-faced mare with hind stockings. In Old English, "bald" means "bright" or "shiny," which could refer to a hairless head or flashy markings (like a bald eagle), just as we say a horse with a lot of white markings has a lot of chrome. In other words, it is very possible that Bald Galloway was a blazed-faced horse, or one with stockings, or both. He may have been a sabino. He may also have been a rabicano, with extensive white hairs on his flanks and white in his tail, since we know the rabicano can have a silvery sheen to its coat. Bald Galloway had a daughter named Silverlocks.
While guessing that Bald Galloway and his sister Points were possibly sabinos or rabicanos may be a stretch, the same conclusion could also explain why Regulus and Cade, both out of daughters of Bald Galloway, might sire so many roan horses. Since many of these roans came from parents neither gray nor roan, we have to presume that one or both of their parents were minimally marked rabicanos, perhaps, like Cox's Ridge or Birdcatcher, just with white ticks in their coat and white hairs at the root of their tail. And, quite possibly, when a minimally marked rabicano is crossed with a minimally marked rabicano, the result can be a strikingly marked rabicano who appears for all intents and purposes to be a roan.
Contrary evidence
There are a few of these eye-catching horses in the American Stud Book. One was Carrier Pigeon, a foal of 1937 who was registered as a "chestnut roan."
Carrier Pigeon was an attractive chestnut with a lot of white hairs in his coat, especially along the flanks, and white hairs at the root of his tail. He seems to have passed his rabicano gene on to his daughter Corday, who in turn passed it on to her daughter, Our Martha, who was also a chestnut with extensive scattered white hairs and white hairs in her tail. Our Martha produced Cox's Ridge, who had Birdcatcher ticks and passed them on generously to his offspring. Carrier Pigeon was by the dark chestnut Equipoise and out of the bay mare Rockdove, by Friar Rock, a chestnut.
Another startlingly marked Thoroughbred was Pilate, who was a chestnut with white and gray hairs scattered throughout his coat, and dolloped with dark, egg-shaped Bend Or spots as well. Pilate was a son of Friar Rock out of the gray mare *Herodias, by The Tetrarch. Before you point fingers at the weirdly marked The Tetrarch as the source of all strange coat colors, please compose yourselves and remember that Carrier Pigeon's dam was a daughter of Pilate's sire, Friar Rock. To add to the genetic possibilities, *Herodias's dam was Honora, a daughter of the chestnut sabino Gallinule, who appears in the background of many flashy Thoroughbreds.
Another example is the Maryland stallion Berkley Prince, who was originally registered as a roan but was later changed to chestnut. The "Prince of Elberton" Farm in Maryland had extensive white ticking and white at the root of his tail. He was by the bay Rash Prince (by Prince John) and his dam was the bay Betrayed, by Tip-Toe. Betrayed was a daughter of the mare Pyrrha, by Pilate. Rash Prince was a son of Prince John, a chestnut with a blaze and white hairs in his coat but not white in his tail. Prince John threw a lot of excess white and more than a few suspiciously roany-looking animals such as Mandate. Interestingly enough, Prince John also goes back in direct female line to Pilate's dam, *Herodias.
Rash Prince went back in female line to Friar's Carse, by Friar Rock. (Friar's Carse is the dam of War Relic, who also had white ticking in his coat.) Berkley Prince's best offspring was the top mare Weber City Miss, dam of Slew City Slew, who also has rabicano characteristics and throws Birdcatcher ticks with regularity.
A particularly colorful case is that of the 1980s stakes winner Contrary Rose. Win photos of Contrary Rose show what would otherwise be described as a strawberry roan; however, the mare was registered as a chestnut. Rose's head and upper legs were solid colored, but her midsection was several shades lighter, overrun with a mix of white hairs, and the top of her tail was like a bright white brush. She was a very gaudy affair, with a broad blaze and four stockings, both up over her knees in front. I would suggest that Contrary Rose was not only a rabicano, but she was also a sabino. Contrary Rose was a most obvious strawberry roan.
Contrary Rose was by Seat of Power, another horse with a lot of chrome, a blaze and stockings, which is unusual on a dark bay or brown body. His dam was the top mare *Beaver Street, by *My Babu, and the next dam was Wood Fire, a daughter of Bois Roussel, who was also covered in Birdcatcher ticks and had a white-topped tail. Contrary Rose's dam was Kari Contrary, who was 5x5 to Friar Rock, once through the mare Tiens, bred very much like Carrier Pigeon, being by Equipoise's sire Pennant and out of a daughter of Friar Rock. All things seem to point to Friar Rock as a rabicano carrier.
So, we come to the end of our little roan adventure. We have learned that the confusion over gray and roan is a silly one created by a misunderstanding of basic terminology. If the horse is getting lighter with age, then it is a gray, pure and simple. But we have also seen that roaning patterns do exist in the Thoroughbred and have since the beginning of the breed, thanks to the presence of the sabino and rabicano genes. So, the question becomes, when is a roan not a roan? Apparently, the answer is, "When it's a Thoroughbred."
Anne Peters is a bloodstock
consultant who lives and works
in Carlisle, Pennsylvania,
where she also edits
Owner/Breeder magazine.
