A filly is a
female
An organism's sex is female ( symbol: ♀) if it produces the ovum (egg cell), the type of gamete (sex cell) that fuses with the male gamete (sperm cell) during sexual reproduction.
A female has larger gametes than a male. Females and ...
horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...
that is too young to be called a
mare. 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 Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
and the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
, the world of
horse racing sets the cutoff age for fillies as five.
Fillies are
sexually mature 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 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
*
Weanling
References
{{Reflist
Types of horse
Female horses
Horse racing terminology