Horse breed been produced. Such restrictions have led to legal challenges in the United States, sometime based on state law and sometimes based on antitrust laws. Horses can crossbreed with other equine species to produce hybrids. These hybrid types are not breeds, but they resemble breeds in that crosses between certain horse breeds and other equine species produce characteristic offspring. The most common hybrid is the mule, a cross between a "jack" (male donkey) and a mare. A related hybrid, the hinny, is a cross between a stallion and a jenny (female donkey). Most other hybrids involve the zebra (see Zebroid). With
Tourist (horse) was a late developing horse who won back-to-back Breeders' Cup Classics, and is known for siring offspring that also tend to develop later in their career and are best at a distance of a mile and up. Tiznow is the most important modern descendant of Man o' War in the direct male line – the sire line traces back to the Godolphin Arabian. Tourist's dam, Unbridled Melody by Unbridled's Song, comes from a strong female family that has produced multiple stakes winners in recent generations. Unbridled Melody produced five named foals, four of them stakes winners. Tourist has been described