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
Now What (horse) the 1952 American Co-Champion Older Female Horse. Now What (horse) Now What (foaled 1937, in Kentucky) was an American Thoroughbred Champion racehorse. Her dam was That's That, and her sire was the 1927 American Horse of the Year and two-time Leading sire in North America, Chance Play. Raced by Alfred G. Vanderbilt II, Now What was trained by Bud Stotler and was a champion at two. As a three-year-old, she finished second in the Molly Brant Handicap, Pimlico Nursery Stakes, and Juvenile Stakes. Now What served as a broodmare for Vanderbilt. Her most successful foal to race was Next Move,