GaitNColor

Breeding for appaloosa Patterned Gaited Horses.

The goal of the Spanish Jennet or Walkaloosa breeder is to produce a well gaited foal with appaloosa coloring. This causes the gamble of breeding to be made even more difficult when adding in the aspect of color. The genetics involved in creating a horse with the appaloosa pattern and characteristics is still an ongoing study.

Although the researchers are getting closer to identifying the genetic mixes that will result in the best chance of good pattern production, today's breeders have to work with observations and information from previous generations as well as offspring of a given horse to form a picture of the horses’ genetic makeup that will result in desired coloring.

When I first started to do my research on appaloosa color inheritance, there was not a lot out there that was based on anything except the experience of individual breeders. I spoke with a gentleman who had raised Appaloosa horses for many years and he explained it to me in a simple manner. He said to think about the appaloosa coloring as white paint splattered on a solid colored horse. If a horse had a lot of dense white patterning, more of the appaloosa had "Stuck" and that horse had more white to "Throw" onto his or her offspring to pass on the high color levels. Although this is far from a scientific explanation, it really does help when trying to figure out how the inheritance behind the color works! At least as far as information is available today.

Research is indicating that the patterns and spots we associate with the appaloosa pattern are Polygenic - traits in which several genes contribute to the overall phenotype. LP is the main gene responsible for appaloosa coat patterning and related traits (white sclera, stripes of light material in the hooves and mottled / depigmented skin on the muzzle, eye and perineal region). LP and the other genes that affect the inheritance of what we associate with high colored appaloosa horses are an ongoing study. These include factors that modify, boost or suppress high color levels when the appaloosa characteristics are inherited. The Appaloosa Project is a group conducting ongoing research. As of now most of their information is based on theories, which cannot be proven or disproved until DNA testing becomes available (something researchers are VERY close to!).

Example of Snowcap appaloosa

A horse who has a blanket of solid white from the withers back ( mid-barrel (50%) or less) is known as a Snowcap. Fewspot is a shortened name for "Fewspot Leopard". As the name implies, the horse has a "full-body" white pattern causing an average of about 80% of the body to be solid white. Neither Fewspots nor Snowcaps will have dark spots in their white areas, or very few. This is due to the two dominant copies of LP. These horses have genetics that combine the factors that act with LP to produce a large amount of white patterning on the body, ranging from rump-sized to up-to-shoulder blankets. Snowcap and Fewspot horses are considered by breeders to be 100% color producers, their offspring will inherit the LP from them EVERY time. It is now a matter of whether they will inherit the pattern factors that combine to produce high color levels.

Other inheritance would include appaloosa roan pattern development and the interaction of Sabino expression.

Sabino expression - will normally boost appaloosa pattern levels, but Sabino-type markings are being seen to reduce the number and size of spots. This can lead to suppression of dark spots on white areas to such a degree that a "false Fewspot" or "false Snowcap" phenotype can result. (Suppression is the "normalizing" effect caused by the action of genes that encourage pigmentation. ) There are two types of modifiers to consider - those that help appaloosa patterning and/or white face and leg markings to be expressed, and those that HINDER. LP-caused appaloosa roaning is where white hairs are unevenly distributed through the base color, often with more over the back and rump areas. As the horse ages these hairs often distribute where the bony or prominent areas are less affected (known as varnish marks), i.e. on the face, the top of the withers, the elbow, point of shoulder, point of hip, stifle and lower leg bones. LP-caused roan patterning called "snowflake" roaning can occur with the above, or on its own. Snowflakes are clusters of white hairs that appear randomly over the body, often occurring more on the front half than the back half of the horse. These may vary in size and position from year to year.

The best chance(s) of consistently producing foals with color comes when you cross a mare and stallion who both exhibit, and from their ancestry and prodigy show, high color patterns. The terms Homozygous; having two identical alleles for a given trait and Heterozygous; possessing two different forms of a particular gene come into play here.

All horses that have appaloosa characteristics, with one parent who has no appaloosa traits are Heterozygous for LP. There is no other genetic possibility. They cannot have inherited the LP gene from a horse with no appaloosa characteristics. Their genotype for this would be LP/lp. The small lp indicating that no appaloosa characteristics or LP mutation are on that given gene group or position along a chromosome (a locus). This means only ½ of the time can they pass the LP to their offspring. First generation crosses in the Spanish Jennet or Walkaloosa need to be from crosses where at least one of the horses is Homozygous for the LP gene. This insures that at least one copy is inherited by the offspring. Horses accepted within the research community and by experienced breeders to be Homozygous for LP are the true Fewspot and Snowcap horses of Appaloosa parentage. To my knowledge, a true Fewspot or Snowcap has not been produced in appaloosa patterned gaited horses that are not full Appaloosa. (UPDATEWe HAVE ONE!) Of course this is what a breeder needs to strive for! The Homozygous animal will produce the LP EVERY TIME in his or her offspring.

LP by itself will not result in a loudly marked appaloosa horse. The genetics that combine the factors that act with LP to produce a large amount of white appaloosa patterning on the body have to be inherited as well. A true Fewspot or Snowcap has to be at least heterozygous for the these modifiers.

Example of Fewspot

To sum up the above, when using a solid gaited horse crossed with an appaloosa patterned horse to produce loudly colored offspring for the first generation, the best results will be seen when the appaloosa patterned horse is a Fewspot or Snowcap. This will produce the largest numbers of Heterozygous, but loudly colored patterned animals. If the Fewspot or Snowcap is also Homozygous for the other genes that affect the inheritance, the results will be 100% inheritance for these modifiers to produce all Leopard marked or Blanket patterned foals.

Now we come to our Second Generation. All of the First Generation that inherited color, from the above scenario is going to be Heterozygous for LP, and in the case of the loudly patterned offspring Heterozygous for the factors that act with LP to produce a large amount of white patterning on the body. Since the definition of a Spanish Jennet or Walkaloosa is that the animal is gaited, to reinforce this inherited tendency we need to breed back to GAITED stock. Otherwise, we risk losing the gait in our prodigy. Then we become just another breed of color, which is of course not the aim of the Breeder.

Unfortunately this means in our cross of two high colored gaited horses, to achieve our Second Generation, both are Heterozygous for the other genes that combine for high patterned horses. Alternately we are breeding Heterozygous for the genes that combine for high patterned horses to solid gaited horses for our Second Generation. Both of these scenarios will result in a % of the offspring having NO appaloosa patterning or characteristics. Although the plus is, they should retain the gait!

As a breeder you have to decide what you goals are. Are you breeding for long term results? Or next year’s market? Next year’s market can be most readily accommodated by breeding a Homozygous Appaloosa (Fewspot or Snowcap) to well gaited mares who themselves are solid. You would produce horses that are in all likelihood gaited, and would definitely have LP. If you were fortunate enough to use an Appaloosa who was also Homozygous for the other genes that combine for high patterned horses, you would also get high color levels in all the offspring.

Snowcap appaloosa - Roaning

The next scenario is to breed the 2 Heterozygous for LP and for the other genes that combine for a high patterned Gaited horse to another of the same. This will result in 1/2 of the offspring being high patterned. That is, blanket or leopard patterned and Heterozygous for LP & for the other genes that combine for high patterned horses; in essence the same as the parents. But it should also cause you to have a ¼ of your offspring without any appaloosa characteristics. They should retain the gait (after all they are still 50% gaited stock). In other words, by all outward appearances just like the original gaited stock you started with, including the ability to gait. BUT ¼ of the time (by percentages), you are going to produce the sought after GAITED appaloosa patterned animal who is now homozygous for the LP AND homozygous for the other genes that combine for high patterned horses! These animals then would become the crux of your breeding herd, as they WILL produce appaloosa characteristics with high pattern 100% of the time when bred! (UPDATE DID I mention ...We HAVE ONE!)

The catch 22 in the whole breeding for GAITED appaloosa patterned horses scenario comes from the fact that the best way to produce the Fewspot or Snowcap (3/4 of the time odds genetically) would be to breed our first generation (Heterozygous for LP and for the other genes that combine for high patterned Gaited horses), to a Homozygous Appaloosa (Fewspot or Snowcap). But herein lays the problem of the horse produced now only being ¼ of gaited stock. Even though you have high chances of producing the Fewspot or Snowcap in this cross, you could very well be sacrificing gait.

Since gait is what makes these horses special, the way to strengthen the gaiting genetics is to breed back to well gaited mares of full gaited bloodlines, in other words solid mares. This is the hard decision for a breeder, as you are going to get a much lower percentage of high color offspring than the previous example,. BUT they will be ¾ of gaited heritage. When you DO get a high color Heterozygous LP & for the other genes that combine for high pattern in this cross, it is an animal who will concentrate your gaiting ability. And when used with the other animals in our 1st Generation example, they/you can now produce a horse that is a Fewspot or Snowcap and be 5/8 gaited stock genetically. Of course, this SHOULD translate to a WELL gaited animal capable of transmitting gait and appaloosa color!
Breeding is always going to be a gamble. Successful breeders have learned to help the odds to being their favor by learning to apply science, history and a little bit of common sense to the breeding mix. Good luck in your future foal crops for GAITED appaloosa Colored Horses!