What is the term for a castrated male horse of any age?

The term for a castrated male horse of any age is "gelding." This designation applies regardless of the horse's age, meaning that a gelding can be a young horse or an older one, as long as it has undergone the surgical procedure of castration. Gelding typically makes horses easier to manage, as the removal of the testicles reduces certain behaviors often associated with intact males, such as aggression and territoriality.

In contrast, a colt refers specifically to a young male horse that has not been castrated, while a stallion is an intact male horse capable of breeding. A filly, on the other hand, is a young female horse. Understanding these terms is crucial for equine management and breeding knowledge, as they indicate not only gender but also reproductive status.