Quis Smart Program Horse owner who plan to breed one or more mares should have a working knowledge of heredity and know how to care for breeding animals and foals. The number of mares bred that actually conceive varies from about 40 to 85 percent, with the average running less than 50 percent. Some mares that do conceive fail to produce living foals. This means that, on average, two mares are kept a whole year to produce one foal, and even then, some foals are disappointments from the standpoint of quality. By careful selection, breeders throughout history have developed various kinds of horses with a wide variety of characteristics to suit many different needs. The Great Horse of the Middle Ages, for example was bred for size and strength to carry a heavily armored knight. The massive horses of such breeds are often called “cold blooded.” The Arabs bred lithe dessert horses that were small and swift. These animal are often referred to as “hot blooded.” Cross-breeding of hot blooded an