What is a Mare in Horse Racing?

One of the things that may catch out those fairly new to horse racing is the description of horses’ sex.

While ‘colt’, ‘gelding’, ‘entire’, ‘sire’, ‘stallion’ or simply ‘horse’ are all used to describe males, ‘fillies’ and ‘mares’ are our female racehorses.

Essentially a mare is an adult female equine animal.

Female mules and zebras are also called mares.

In the wider equine world, mare can be used to describe any female over the age of three. In horse racing however, that is a little different.

At two, three and four, the females are still called fillies in thoroughbred horse racing.

When they turn five, all of them together in the Northern Hemisphere on January 1^st, they are then described as mares.

What Changes When Females Move From ‘Filly’ to ‘Mare’?

Well, basically nothing.

This is just an age thing, more accurately describing the horse’s maturity. Maturity of course is very individual and open to some interpretation, much in the same way that people will argue over when a human female moves from being a girl to a woman.

One noticeable change is how the horse is described in the racing press.

Some people will colloquially say “filly” when a horse is five or over, which is fine, much like calling an older woman “girl” or “lass”. The racing press however much accurately display that a female over four is now a mare.

Al Husn, the example on the left, is still a filly at four years old. Hence her age, foaling date, colour and sex are listed as: 4yo (03 Apr 19) b f, meaning four-year-old, foaled on April 19^th 2019, bay, filly.

The example on the right is Potapova, a five-year-old mare, hence the use of ‘m’ for mare instead of ‘f’ for filly.

Broodmares

Just to be thorough, females aged five and over still running on the track are often called ‘racemares’. This is almost to distinguish them from ‘broodmares’ which, as you can imagine, simply means a mare used for breeding after retirement from racing.

Fillies and mares are usually better behaved than male horses, especially colts. Many might say that this replicates human behaviour too!

The other major difference between the males and the females is how often they can be used for breeding. A typical stallion can cover 100 or more mares in a breeding season. This is why all the sons of Dubawi, Galileo, Frankel etc are not considered half-brothers.

A half-sibling is a horse with the same dam, or ‘mother’. Full siblings, naturally, have both the same sire and same dam.

A ‘breeder’ is not considered to be the person or entity owning the sire, but the person or entity which owns the broodmare. The risk is all on this side; once your mare is covered by a stallion, for which you will need to pay a fee, they may or may not be in foal afterwards.

Then, the hope is that there is nothing wrong with the pregnancy and only after that, you hope that your foal is fit and well and becomes a good racehorse a couple of years later or more.

Broodmares carry their foals for around 11 months. That gestation period means of course that the mare will produce only one foal each year, often less.

Mares Only Races

In the early part of a horse’s career, they will race only in their own age group. Two-year-olds race mostly against each other all season, even splitting into colts and fillies’ races.

Similar happens when they are three, including with the Classics, until midsummer when they start to go up against the older horses with a weight allowance.

Even as they get older however, there are races put on all season for fillies and mares only on the Flat, and for mares only over the jumps.

Here are some of the better examples:

Month	Race	Type	Track	Distance	Conditions
Jan/Feb	Yorkshire Rose Mares’ Hurdle	Jumps	Doncaster	2m	4yo+ M
Mar	Dawn Run Novices’ Hurdle	Jumps	Cheltenham	2m1f	4yo+ M
Mar	Mares’ Chase	Jumps	Cheltenham	2m4f	4yo+ M
Apr	Mares’ Novices’ Limited Handicap Chase Final	Jumps	Cheltenham	2m4f	5yo+ M
May	Middleton Stakes	Flat	York	1m2f	4yo+ F&M
June	Duke of Cambridge Stakes	Flat	Ascot	1m	4yo+ F&M
July	Lancashire Oaks	Flat	Haydock	1m4f	3yo+ F&M
July	Falmouth Stakes	Flat	Newmarket (July)	1m	3yo+ F&M
July/Aug	Nassau Stakes	Flat	Goodwood	1m2f	3yo+ F&M
Aug	Yorkshire Oaks	Flat	York	1m4f	3yo+ F&M
Oct	Sun Chariot Stakes	Flat	Newmarket	1m	3yo+ F&M
Oct	British Champions Fillies & Mares Stakes	Flat	Ascot	1m4f	3yo+ F&M