partbred Arabian

thumb|Part-Arabian, part-Friesian cross thumb|Araloosa cross A part-Arabian, partbred Arabian or, less precisely, half-Arabian, is a horse with documented amounts of Arabian horse breeding but not a purebred. Because the Arabian is deemed to be a breed of purebred horse dating back many centuries, the modern breed registries recognized by the World Arabian Horse Organization generally have tightly closed stud books which exclude a horse from registration if it is found to contain any outside blood. However, Arabian breeding has also been used for centuries to add useful traits to countless other horse breeds. In the modern era, crossbreeding has been popular to combine the best traits of two different breeds, such as color, size, or ability to specialize in a particular equestrian discipline.

Thus, in the modern era, the desire to recognize and acknowledge Arabian breeding in non-purebred horses has led to the formation of partbred sections in many purebred Arabian registries in order to record the pedigrees of crossbreds. Some registries, particularly those for sport horses and various warmbloods, have an open or partially open stud book that still allows some infusions of Arabian blood as well as that of other breeds, sometimes based on a documented Arabian pedigree, sometimes on a pedigree plus a studbook selection process. In addition, some particularly successful or popular designer crossbreds created their own registries, some now closed to most outside breeding, though generally allowing additional infusions of purebred Arabian blood. Some horses may qualify for recording with more than one registry.