What Gender Are the Horses in the Kentucky Derby?
If you’ve ever watched the Kentucky Derby, you might wonder what gender the horses are. Are they all male? Can female horses race? And what makes a horse eligible to compete in this iconic event?
This article answers those questions in simple terms and explains how gender plays a role in the world of Thoroughbred racing—especially in the Kentucky Derby.
What Gender Are the Horses in the Kentucky Derby?
Most horses in the Kentucky Derby are male—specifically colts, which are uncastrated male horses under the age of four. Geldings (castrated males) can also compete, though they’re less common. Female horses, called fillies, are allowed to race in the Derby, but it’s rare.
The race is open to 3-year-old Thoroughbreds of any gender, but colts tend to dominate due to physical strength and traditional racing strategies.
What’s the Difference Between Colts, Fillies, and Geldings?
Here’s a quick guide to horse racing genders:
| Term | Definition |
|---|---|
| Colt | Male horse under 4 years old (not gelded) |
| Filly | Female horse under 4 years old |
| Gelding | Castrated male horse |
All Kentucky Derby horses must be 3 years old. This age restriction creates a level playing field but limits the chance to see older, more developed horses compete.
Why Are Most Kentucky Derby Horses Male?
Colts tend to be larger, stronger, and more aggressive on the track, which gives them a competitive edge in fast-paced races like the Derby. Breeders and trainers often aim male horses at the Triple Crown races because of these physical advantages.
Female horses may be just as fast, but they are usually entered in female-only races such as the Kentucky Oaks, which runs the day before the Derby.
Have Female Horses Ever Run in the Derby?
Yes, fillies have competed in the Kentucky Derby—but very rarely. In the race’s 100+ year history, fewer than 50 fillies have entered, and only three have won.
Notable fillies in Derby history:
- Regret (1915): First filly to win the Kentucky Derby
- Genuine Risk (1980): Second filly to win
- Winning Colors (1988): Third filly to win
Since then, few fillies have attempted the Derby. Most compete in the Kentucky Oaks or other Grade 1 races tailored for females.
Can Geldings Compete in the Kentucky Derby?
Yes, geldings are allowed in the Derby and have won in the past. While colts are preferred for their future breeding value, geldings can still have successful racing careers and are sometimes more focused or easier to handle.
Famous gelding winner:
- Mine That Bird (2009): A gelding who won the Derby in a major upset at 50-1 odds
Since geldings can’t be used for breeding, their careers often last longer, as their owners don’t rush to retire them after major wins.
Why Don’t More Fillies Run in the Derby?
Trainers often prefer to run fillies in the Kentucky Oaks, where they compete only against other females. The Oaks offers high prize money and prestige without the physical demands of racing against colts.
Breeders also may protect fillies from high-intensity races to preserve their value as broodmares later on.
What’s the Gender Breakdown in a Typical Kentucky Derby?
Out of the 20 horses that usually enter the Kentucky Derby, 18–19 are typically colts, and occasionally 1–2 may be geldings. Fillies are extremely rare and might only enter once every several years.
So, while the race is open to all, tradition, performance, and breeding influence the makeup of the field heavily in favor of males.
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Conclusion
While both male and female horses are eligible to compete in the Kentucky Derby, the field is almost entirely made up of colts and the occasional gelding. Fillies can run but rarely do, mainly due to physical differences and tradition within the sport.
Whether you’re a fan or a first-time viewer, understanding the role of gender in racing adds a whole new layer to enjoying this legendary event. Explore more horse-related insights here and keep learning about the fascinating world of Thoroughbreds.