22 April, 1962
Color Inheritance Factors( Continued from Page 13) reddish to dark liver colors. Manes and tails may be color of body or flaxen.
GREYS: Black and white hair. May be almost white or black. Usually dark when born, turning lighter with age.
ROANS may be any shade or color interspersed with white hairs. They come in all shades and are not always born Roan.
PALOMINO— a color group having yellow body with light mane and tail. Probably belong in a group with cream or white with white or silver mane and tail. Some very light Sorrels with white mane and tail could be a related color. Sometimes born Sorrel.
DUNS— here we have some disagreement by placing all buckskins, mousecolored, clavbanks and creams in one group instead of placing them with the Palominos, but in the duns we usually find the dorsal stripe and the coat appears diluted.
PIEBALD and SKEBALD-any irregular color with white area. May be in combination with the above colors. Piebald is black and white; Skebald is other colors and white.
Unit Characters Inherited
From the standpoint of inheritance, all animals are made up of a large number of inherited unit characters. Many, rather than one gene, function in developing each unit character, and unit characters dominate others during the development of the individual— thus determining its apparent characteristics.
A recessive character, unable to manifest itself in the presence of the dominant unit character, may be carried along for many generations to appear later when it finds itself linked with a like recessive unit character.
Now, observe how this applies to the action of color genes in horses.
ROAN is believed to be dominant to all other colors.
GREY is dominant to all except Roan, but their exact relationship to one another is not entirely understood due to their close resemblance.
BAY is considered dominant over Black, while Black is dominant over Chestnut.
The Dun group is considered dominant over all except Grey and Roan and possibly pied or spotted. Pied or spotted is considered domi-
Proved By Many Tests nant to all others except Grey and Roan but seems to be heterzygous( mixed) for some other color, possibly white.
If we class Palomino as belonging to the Ysabella or Flaxen mane group, then it would be very much like Sorrels or Chestnuts and possibly be recessive to all other colors like Sorrells and Chestnuts.
Under the above arrangement we find that Chestnut is the only color Lliat is definitely known to be recessive, and consequently the only color to breed true.
I find no data on the Appaloosas and just how they fit into this scheme would be purely speculative. But from the large number of horses of this color suddenly showing up in the horse family, it must either be a dominant color or homozygoes for some other colors. We find these peculiar markings showing up on all colors of horses. I have suspected that these markings may be a separate unit factor in color and act independently of coat color similar to leg and face markings on other coat colors.
15,000 Crosses Studied
In one study with 15,000 crosses of Chestnuts on Chestnuts we find only 16 oll-colors, and this is very likely due to errors in identifying the colors on the part of those persons registering offspring. With 340 crosses of Black with Chestnut we found 83 Blacks, 111 Chestnuts, 20 Browns and 124 Bays. Bays crossed with Bays produced 474 Chestnuts, 107 Blacks, 300 Browns and 2,831 Bays. No Roans or Greys were produced by any crosses of Chestnuts, Blacks, Bays or Browns. All Roans and Greys were produced from crosses or Greys or Roans. No Albinos, Pieds or Palominos were recorded here.
With this scheme of the law ' s of recessiveness and dominance, let us cross a pure Grey sire with a Chestnut mare. We get four Grey offspring, all carrying both the Grey and the Chestnut factor. When w ' e cross these in the next generation we get three Greys and one Chestnut, the latter being pure Chestnut. There are two hybrid Greys and one pure Grey. The pure Greys cannot be distinguished from hybrid Greys, and only the Chestnut can be said to be pure in color factors.
An interesting case of the action in these recessive factors is that of the Palominos showing up in the Tennessee Walking Horse— where only one foundation yellow horse was recorded. But within a few ' years more than four hundred yellow horses were recorded. These laws of inheritance seem to work in reverse in the mules as there are many Sorrel or Chestnut mules but none in the Donkey family.
In discussing die leg and head markings, it seems very evident that these markings are a separate factor and are not linked directly with color of body. In some breeds we find very elaborate leg and head markings like those found in Walking Horses, while in Thoroughbreds we find very little.
Some writers on this subject have thought these elaborate markings were simply Albinoism asserting itself, while others assert the inbreeding of these horses with much white markings tends to produce this characteristic in a double dose.
Probably the latter theory is responsible for the Palomino breeders discriminating against horses with markings above the hocks and knees. I have observed that many white horses result from the crossing of these Roans with much white on the legs and head.
It is not my purpose to cover this subject in its entirety, but rather to point out some facts and problems concerning those attempting to breed horses for color.
Popularity In Cycles Popularity of color runs in cycles. DUN w ' as the favorite color for Western stock horses in the Old West, while it is giving way to Chestnuts and Bays now '.
The Leopard or Appaloosa was at one time considered an objeclional color but now ' appears a favorite color among many horse fanciers.
There are some disadvantages to colors, as Albinos with light eyes have difficulty in hot sunlight, and bald face horses sunburn around the nose. Blacks sunburn badly and get smutty when left in the sun.
Some colors are said to be better for hot climates than others. A few breed associations discriminate against certain colors, but some associations do not discriminate against any color, and register solely on pedigree.
Whether it is a Bay Thoroughbred, a Grey Arabian, a stockinged, bald faced Red Roan Walking Horse, a White-maned Palomino or a coyote Dun mustang, I still contend I never saw a good conformation horse and a good doing horse that had a bad color.