What does the E-effect mean to Appaloosa breeders?
The best way to understand this is through an example. Take two fewspot stallions, one a bay, and the other a chestnut, both with 90% white levels. Breed them to identical twin (I know theres no such thing!) non-Appaloosa mares. If both foals produced have the same base colour, the foal from the bay fewspot sire will have a significantly higher white pattern level than the foal sired by the chestnut fewspot. The reason is simple in order for it to have the same apparent level of white as the chestnut stallion, the bay horse has to have more or stronger white-helping modifiers. You may have to do this experiment a number of times to get the difference to show in terms of averages of the two stallion data sets, but it will be there. What this implies for Appaloosa breeding is significant. Eumelanin, the black/brown pigment present in highest amounts in E-base coat horses, “outshouts” white pattern genes more than eumelanin, the red/gold pigment. This suppressing effect by the black gene
