The term "German Warmblood" refers to certain regional horse breeds in Germany like the Oldenburg, the Holsteiner, the Hanoverian, the Westphalian and the Trakehner. These types of horses are named and identified by the region in which they were bred; this means that if a Hanoverian horse is moved to the Westphalian region and is bred there, the offspring will be known as Westphalians. Except for the Trakehner, which is now a definite breed with distinctive characteristics, the rest of the German Warmblood horses are not true breeds with a closed stud book. These breeds are still evolving, and are being bred with other German Warmbloods, Thoroughbreds and Arabians in order to improve their stock by enhancing or introducing certain desired characteristics.
Originally, the German Warmblood horses were bred for agricultural, military and transport purposes; they were used to pull plows, carriages, cannons, as well as for riding. After the invention of the combustible engine, it became unnecessary for the horses to be used for their physical strength. Breeders now became more focused on producing horses based on their physical attractiveness and amenable temperament.
The breeding of German Warmblood horses is a carefully vetted process. The horses, usually between the ages of three and five, have to undergo and pass various physical and temperament tests before they are approved for breeding. Each horse is registered in a regional breed registry; it cannot be registered in more than one registry. It is possible, however, for a horse from one registry to be selected for breeding by another breed registry. These carefully kept records allow breeders to trace the bloodlines of the Warmblood horses accurately, and to select the right stallions and mares for breeding.
There are many principal and provincial studs in Germany. The principal studs keep both mares and stallions, and direct their own breeding programs. The provincial studs, on the other hand, usually only keep specially selected, high quality stallions. For a specified breeding fee, horse breeders can improve their Warmblood stock by breeding their mares with these stallions.
As mentioned, the German Warmblood breed is still evolving, and there is no single breed standard for these horses. There are, in fact, quite a few regional variations, with specific characteristics being enhanced according to the breeder's preferences. The horses may be bred to be of a certain color, size, height, temperament and so on. In some cases, the physical difference may not even be very distinctively apparent.