A filly is a
female horse that is too young to be called a
mare
A mare is an adult female horse or other equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more than fo ...
. There are two specific definitions in use:
*In most cases, a ''filly'' is a female horse under four years old.
*In some nations, such as the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
and the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, the world of
horse racing sets the cutoff age for fillies as five.
Fillies are
sexually mature
Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definiti ...
by two and are sometimes bred at that age, but generally, they should not be bred until they themselves have stopped growing, usually by four or five.
[Ensminger, M. E. ''Horses and Horsemanship: Animal Agriculture Series.'' Sixth Edition. Interstate Publishers, 1990. p. 149-150] Some fillies may exhibit
estrus
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous ...
as
yearlings.
The equivalent term for a male is a
colt. When horses of either sex are less than one year, they are referred to as
foals.
Horses of either sex between one and two years old may be called yearlings.
See also
*
Filly Triple Crown The Triple Tiara of Thoroughbred Racing, formerly known as the Filly Triple Crown, is a set of three horse races in the United States which is open to three-year-old fillies. Presently the only official Triple Tiara is the three race series in New Y ...
*
Weanling
A weanling is an animal that has just been weaned. The term is usually used to refer to a type of young horse, a foal that has been weaned, usually between six months and a year. Once it is a year old, the horse is referred to as a yearling.
The ...
References
{{Reflist
Types of horse
Female horses