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A hoof ( or ), plural ''hooves'' ( or ) or ''hoofs'' , is the tip of a toe of an ungulate mammal, strengthened by a thick, horny, keratin covering. The hoof consists of a hard or rubbery sole and a hard wall formed by a thick nail rolled around the tip of the toe. The weight of the animal is normally borne by both the sole and the edge of the hoof wall. Hooves grow continuously, and are constantly worn down by use. Most even-toed ungulates (such as sheep, goats, deer, cattle, bison and pigs) have two main hooves on each foot, together called a cloven hoof.〔The term "cloven hoof" therefore being a technical misnomer as nothing is actually "cloven".〕 Most of these cloven-hoofed animals also have two smaller hoofs called ''dewclaws'' a little further up the leg – these are not normally used for walking, but in some species with larger dewclaws (such as deer and pigs) they may touch the ground when running or jumping, or if the ground is soft. In the mountain goat, the dewclaw serves to provide extra traction when descending rocky slopes as well as additional drag on loose or slippery surfaces made of ice, dirt, or snow. Other cloven-hoofed animals (such as giraffes and pronghorns) have no dewclaws. In some so-called "cloven-hoofed" animals such as camels, there are no hooves proper – the toe is softer, and the hoof itself is reduced to little more than a nail. Some odd-toed ungulates (equids) have one hoof on each foot; others have (or had) three distinct hoofed or heavily nailed toes, or one hoof and two dewclaws. The tapir is a special case, having three toes on each hind foot and four toes on each front foot. File:Horse hoof wild bare sagittal.jpg|Sagittal section of a wild horsehoof. Pink: soft tissues; light gray: bone; blue: tendons; red: corium; yellow: digital cushion; dark gray: frog; orange: sole; brown: walls File:Masai Giraffe right-rear foot.jpg|Rear foot of a giraffe (no dewclaws) File:Horse rear hooves.jpg|Rear hooves of a horse File:Camelsfootforexceedinglyimportantarticle.jpg|Camel hoof Image:Tapir hooves.jpg|Malayan tapir hooves: front with four toes, back with three toes ==Uses== Hooves have historical significance in ceremonies and games. They have been used in burial ceremonies. Hooves have also been used in the manufacture of high-end glues. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「hoof」の詳細全文を読む スポンサード リンク
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