Yearling (horse)
Young horse of either sex that is between one and two years old / From Wikipedia, the free encyclopedia
A yearling is a young horse either male or female that is between one and two years old.[1] Yearlings are comparable in development to a very early adolescent and are not fully mature physically. While they may be in the earliest stages of sexual maturity, they are considered too young to be breeding stock.[2]
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/e/ea/SilverMorgan.jpg/320px-SilverMorgan.jpg)
Yearlings may be further defined by sex, using the term "colt" to describe any male horse under age four, and "filly" for any female under four.