Every year the total numbers of foals born is approximately divided into 50% colts and 50% fillies.  The numbers of colts that are allowed to retain their masculinity as future stallions are proportionately very small, the majority being gelded. 

Unless you are someone who is breeding selectively either for sale or to maintain or improve the breed, most colts should be gelded.  Keeping a colt as an entire on a whim or just to see how it turns out is not a good idea and should be discouraged.  The management of colts, especially when they become mature, has its difficulties and obvious dangers and unless one has the facilities and expertise, this is an area that is best avoided. 

Autumn is a good time to get the “evil deed” done.  Preferably the operation should be carried out when the foal is about four to five months old and still suckling the mare.  The surgery in most cases is carried out under sedation and a local anaesthetic, the foal quickly recovers and has the comfort of being with its mother, this seems to reduce stress and complications.  The foal can then be safely be weaned from the mare two to three weeks later or at around five to six months of age.