Geldings
If a stallion is not to be used for breeding, gelding the male horse will allow it to live full-time in a herd with both males and females, reduce aggressive or disruptive behavior, and allow the horse to be around other animals without being seriously distracted. If a horse is not to be used for breeding, it can be gelded prior to reaching sexual maturity. A horse gelded young may grow taller and behave better if this is done. However, older stallions that are sterile or otherwise no longer used for breeding may also be gelded and will exhibit calmer behavior, even if previously used for breeding. Modern surgical techniques allow castration to be performed on a horse of almost any age with relatively few risks.
In most cases, particularly in modern industrialized cultures, a male horse that is not of sufficient quality to be used for breeding will have a happier life without having to deal with the instinctive, hormone-driven behaviors that come with being left intact. Geldings are safer to handle and present fewer management problems. They are also more widely accepted. Many boarding stables will refuse clients with stallions or charge considerably more money to keep them. Some types of equestrian activity, such as events involving children, or clubs that sponsor purely recreational events such as trail riding, may not permit stallions to participate.
However, just as some pet owners may have conflicting emotions about neutering a male dog or cat, some stallion owners may be unsure about gelding a stallion. One branch of the animal rights community maintains that castration is mutilation and damaging to the animal's psyche.
Read more about this topic: Stallion