Genetics
Homozygous vs. Heterozygous

Since I use the terms "homozygous" and "heterozygous" quite a bit, I thought I should offer a short definition.

A horse that is heterozygous carries one copy of a particular gene*. The horse will produce a foal carrying the gene 50% of the time when bred to a horse without the gene. Heterozygous cream dilutes are: palominos, buckskins, and smokey blacks.

A horse that is homozygous carries two copies of a particular gene*. The horse will produce a foal carrying the gene 100% of the time whether or not the horse it is bred to carries the gene. In order for a horse to be homozygous for ANY gene, both of the horse's parents must have the gene and pass it. Homozygous cream dilutes are: cremellos, perlinos, and smokey creams.

*By a particular gene, I mean any gene. This can be the red gene, black gene, agouti, cream, champagne, gene for height, flaxen, gene for big ears...any gene.


Westwood Farms - Locust Dale, Virginia 22948 - stephanie@westwoodfarms.net - 540-825-1300