Horse training for racing is fascinating.
Yes it is, before they were trained for racing, they were trained for warfare. 
That is understandable, but a shame.    Beautiful animals.
Some horses are trained for specialized jobs for movies and circus entertainment. Not sure how great of a life for that kind of a horse is. 
True, but better than being shot!
Cowboy
A cowboy is an animal herder who tends cattle on ranches in North America, traditionally on horseback, and often performs a multitude of other ranch-related tasks. The historic American cowboy of the late 19th century arose from the "vaquero" traditions of northern Mexico and became a figure of special significance and legend. A subtype, called a wrangler, specifically tends the horses used to work cattle. In addition to ranch work, some cowboys work for or participate in rodeos. Cowgirls, first defined as such in
Horse training
Horse training refers to a variety of practices that teach horses to perform certain behaviors when commanded to do so by humans. Horses are trained to be manageable by humans for everyday care as well as for equestrian activities from horse racing to therapeutic horseback riding for people with disabilities.
Historically, horses were trained for warfare, farm work, sport and transport. Today, most horse training is geared toward making horses useful for a variety of recreational and sporting equestrian pursuits. Horses are also trained for specialized jobs from