Basic Genetic Principles

Want to understand a little bit more about Color Genetics in horses? Here's a basic primer and some suggestions for further reading. For something more detailed, click here.
Basic Genetics
To understand how color is determined in horses, you have to know three things about basic genetics:

  1. Horses have thousands of genes.  Each gene controls a different trait – eye color, hoof size, temperament, etc.  Some traits are simple – controlled by one gene.  Others are complex, controlled by many genes working together.  Color is one of the complex genes.  It is controlled by the interactions of many genes working together.
  2. Every horse receives two versions of each gene – one from the mother and one from the father.  A specific gene may have many more than two versions available in the whole horse population, but each individual horse only gets two.
  3. When a horse receives two different versions of a gene (instead of getting the same version from both its mother and its father), these traits usually do not blend – most often, one is hidden (turned off) and the other is used to build the foal.  However, when breeding, it is important to remember that the hidden gene exists.  After all, it may be the hidden gene that gets passed on to its foal, and this may create a trait in the foal that was not present in either parent.