The term "Lineback Dun" is confusing to some, as it gives the impression that there ought to be such a thing as a "non-lineback Dun." There isn't. The genetic factor which produces Dun always produces the line, though it may be of varying widths. The edge of the line of a linebacked dun is crisp and definite unless obscured by the presence of Sooty.

The Lineback Dun coloration appears in all the strains of the Turkoman horse including the Akhal-Teke, as well as in the Caspian and the Moroccan Barb. Very curiously, it does not appear in the modern-day Arabian horse. Additionally, it does not appear in the Thoroughbred either, possibly because Europeans so closely associated the Dun coloration with draft or pony blood, or possibly because of the elsewhere-mentioned prejudice against the color inherited throughout Europe through the Romans.

Lineback Dun is a dominant trait, and a dun horse will always have at least one dun parent. There is much anecdotal evidence and much breed-association and breeder experience that duns bred to dun generation after generation produce horses with more and more striping -- that is to say, greater degrees of interference -- in each generation. The Akhal-Teke filly below, MV Katrina, shown at two days old, shows clearly all the lines and stripes of the Dun, most of which she kept as she matured. Both her sire and dam are Duns.

The actual color of the Lineback Dun is dependant upon what color the Dun factor is interfering with. The most common coloration people associate with Dun is Dun over Bay, as in the filly at left). Dun over Black or Seal Brown produces Grulla. Over various shades of Chestnut it produces the Claybank, Orange or Red Duns (such as the Orange Dun mare right, photographed at the Niazov (formerly Komsomol) Stud in Turkmenistan), which are often registered by the Akhal-Teke Studbook under Palomino. In the glowing Turkmen strains, the body color of the Dun is nearly that of a bay, probably because of the structure of the hairs which causes more light to be refracted through them than reflected from opaque cores, as in Dun horses of the Lusitano, Quarter Horse and other breeds. The presence of the clear, crisp, straight backstripe which runs from mane to tail is diagnostic in determining whether a horse is a bay or a dun. It should be noted that these "Dark Golden Duns" rarely show much, if any, red in their coats, as would be typical of bay. They are usually a deep golden brown with a decidedly yellowish golden glow.

One, put forward by modern Arabian fanciers, is that "dun is not an Arabian color, but a sign of draft horse or wild pony blood." While Dun does occur in these draft horses and ponies, there is to date no genetic or even historical evidence to show that it never existed in the hotbloods.

Another possibility is that Arabians selected by Europeans for European studs were deliberately selected against if they were dun. There are decided prejudices for and against certain colors in Europe. Many of these appear to have come originally from the Roman poet and historian Virgil, who wrote in 3^rd Georgic, "A bright bay or a good grey is the best color; the worst is white or dun." He did not say upon what he based his opinion.

Dun by itself is rarer in the Akhal-Teke than it is in combination with Dilution, and often mistaken for bay because of its darkness.

Grulla occurs very rarely in all types of the Turanian horse. The hair structure linked to the glowing factor usually evens out the color tones of the horse and makes the Grulla coloration more golden than is seen in other breeds (so "Olive Grulla" is seen more often than "Slate Grulla.")

Dun is dominant; a dun horse will have at least one Dun parent.

A Dun bred to a non-Dun will produce another Dun on average 50% of the time.

Two Duns bred together will produce a non-Dun on average 25% of the time; two non-Duns bred together will not produce a Dun. If one gets a horse which seems to be Dun from such a mating, it is probable that one or both of the parents has its dun factors hidden by the presence of Sooty, Cremello or other factors.

The photo of the Red Dun mare above was taken by and is © 1998 Martha Bowles and is used here with her permission.