Although humans came into contact with horses about 50,000 years ago, they were originally herded for meat and skins. Evidence suggests that they were domesticated about 5,000 years ago - substantially less than many other farm animals including goats, sheep and cattle. Horses are believed to have first been domesticated in the steppes of the eastern Ukraine and central Russia, as people started to lead a more nomadic lifestyle. Historians debate over whether people first rode horses or attached carts to them, but the latter is thought to be the most likely.
The heavy draft horse gives an impression of weight combined with strength. The body is wide and he back broad, often accompanied by rounded withers, which in some breeds, in the interest of increased pulling power, may be higher than the croup. The body is heavily muscled, particularly over the loin and quarters. The shoulders are relatively upright to accommodate the collar, and the legs are thick and short. The heavy horses usually stand between 16 and 18hh. Their actions are short giving maximum traction.
Every horse is different in how it learns and reacts to outside stimuli. Just because training can be accomplished using certain methods for some horses, this doesn’t mean that those techniques will work just as well on every horse. We don’t teach all children the same way, and all horses don’t learn exactly the same way either. In each case, there are issues past and present that we need to keep in mind, as they may impact the effectiveness of our training. The first thing that we must take into account is that no animal or human learns well when they are stressed. Take a test, or try to meet the deadline at work while your teacher or boss stands over you with a whip, yelling and screaming, and occasionally prodding you with a sharp spur to get his point across, and I think you will understand. The only difference between horses and humans is the reaction we get when the teaching method breaks down.
Both human and horse will shut down under stress, both sometimes leave the area to reduce the stress, both resist against stress, and still others will fight if the stress is great enough. Humans may yell at each other, but horses can’t talk and, therefore, often resort to a more physical response. Sometimes they run away hard and fast dragging their owner with them, or just leaving their owner behind. They may also whirl, kick, strike, pull back, buck, dance sideways, rear and a host of other "fun" and "exciting" reactions.