The hoof (: hooves) is the tip of a toe of an

ungulate Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

, which is covered and strengthened with a thick and horny

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

covering.

Artiodactyl Artiodactyls are placental mammals belonging to the order Artiodactyla ( , ). Typically, they are ungulates which bear weight equally on two (an even number) of their five toes (the third and fourth, often in the form of a hoof). The other t ...

s are even-toed ungulates, species whose feet have an even number of digits; the ruminants with two digits are the most numerous, e.g.

giraffe The giraffe is a large Fauna of Africa, African even-toed ungulate, hoofed mammal belonging to the genus ''Giraffa.'' It is the Largest mammals#Even-toed Ungulates (Artiodactyla), tallest living terrestrial animal and the largest ruminant on ...

deer A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...

bison A bison (: bison) is a large bovine in the genus ''Bison'' (from Greek, meaning 'wild ox') within the tribe Bovini. Two extant taxon, extant and numerous extinction, extinct species are recognised. Of the two surviving species, the American ...

cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

goats The goat or domestic goat (''Capra hircus'') is a species of goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the famil ...

, gazelles,

pigs The pig (''Sus domesticus''), also called swine (: swine) or hog, is an omnivorous, domesticated, even-toed, hoofed mammal. It is named the domestic pig when distinguishing it from other members of the genus '' Sus''. Some authorities cons ...

, and

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

. The feet of

perissodactyl Perissodactyla (, ), or odd-toed ungulates, is an order of Ungulate, ungulates. The order includes about 17 living species divided into three Family (biology), families: Equidae (wild horse, horses, Asinus, asses, and zebras), Rhinocerotidae ( ...

mammals have an odd number of toes, e.g. the

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...

, the

rhinoceros A rhinoceros ( ; ; ; : rhinoceros or rhinoceroses), commonly abbreviated to rhino, is a member of any of the five extant taxon, extant species (or numerous extinct species) of odd-toed ungulates (perissodactyls) in the family (biology), famil ...

, and the

tapir Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a Suidae, pig, with a short, prehensile nose trunk (proboscis). Tapirs inhabit jungle and forest regions of South America, South and Centr ...

. Although hooves are limb structures primarily found in

placenta The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...

l mammals, hadrosaurs such as '' Edmontosaurus'' possessed hoofed forelimbs. The

marsupial Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of marsupials' unique features is their reproductive strategy: the young are born in a r ...

'' Chaeropus'' also had hooves.

Description

The hoof surrounds the distal end of the second phalanx, the distal phalanx, and the

navicular bone The navicular bone is a small bone found in the feet of most mammals. Human anatomy The navicular bone in humans is one of the tarsus (skeleton), tarsal bones, found in the foot. Its name derives from the human bone's resemblance to a small ...

. The hoof consists of the hoof wall, the bars of the hoof, the sole and

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

and soft tissue shock absorption structures. The weight of the animal is normally borne by both the sole and the edge of the hoof wall. Hooves perform many functions, including supporting the weight of the animal, dissipating the energy impact as the hooves strike the ground or surface, protecting the tissues and bone within the hoof capsule, and providing traction for the animal. Numerous factors can affect hoof structure and health, including genetics, hoof conformation, environmental influences, and athletic performance of the animal. The ideal hoof has a parallel hoof-pastern axis, a thick hoof wall, adequate sole depth, a solid heel base and growth rings of equal size under the coronary band. There are four layers within the exterior wall of the hoof. From the outside, a hoof is made up of the stratum externum, the stratum medium, the stratum internum and the dermis parietis. The stratum externum and the stratum medium are difficult to distinguish, the stratum externum is thin and the stratum medium is what makes up the bulk of the hoof wall. Inside the hoof wall is a laminar junction, a soft tissue structure that allows the hoof to withstand the demands of force transmission it undergoes. This tissue structure binds the inner surface of the hoof wall, the dermis parietis and the outer surface of the third phalanx. Most even-toed ungulates (such as

goat The goat or domestic goat (''Capra hircus'') is a species of Caprinae, goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the ...

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-hooved animals also have two smaller hooves called

dewclaw A dewclaw is a digit – vestigial in some animals – on the foot of many mammals, birds, and reptiles (including some extinct orders, like certain theropods). It commonly grows higher on the leg than the rest of the foot, such that in di ...

s 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-hooved animals (such as

s and pronghorns) have no dewclaws. In some so-called "cloven-hooved" animals, such as

camel A camel (from and () from Ancient Semitic: ''gāmāl'') is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provid ...

s, the "hoof" is not properly a hoof – it is not a hard or rubbery sole with a hard wall formed by a thick nail – instead it is a soft toe with little more than a nail merely having an appearance of a hoof. Some odd-toed ungulates (

equid Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ...

s) have one hoof on each foot; others have (or had) three distinct hooved or heavily nailed toes, or one hoof and two dewclaws. The

is a special case, having three toes on each hind foot and four toes on each front foot.

Management

Hooves grow continuously. In nature, wild animals are capable of wearing down the hoof as it continuously grows, but captive domesticated species often must undergo specific hoof care for a healthy, functional hoof. Proper care improves biomechanical efficiency and prevents lameness. If not worn down enough by use, such as in the dairy industry, hooves may need to be trimmed. However, too much wear can result in damage of the hooves, and for this reason,

horseshoe A horseshoe is a product designed to protect a horse hoof from wear. Shoes are attached on the palmar surface (ground side) of the hooves, usually nailed through the insensitive hoof wall that is anatomically akin to the human toenail, altho ...

s and oxshoes are used by animals that routinely walk on hard surfaces and carry heavy weight.

Horses

Within the equine world, the expression, "no foot, no horse" emphasizes the importance of hoof health. Hoof care is important in the equine industry. Problems that can arise with poor

horse hoof A horse hoof is the lower extremity of each leg of a horse, the part that makes contact with the ground and carries the weight of the animal. It is both hard and flexible. It is a complex structure surrounding the distal Phalanx bones, phalanx o ...

care include hoof cracks, thrush, abscesses and

laminitis Laminitis is a disease of the feet of ungulates, found mostly in horses and cattle involving inflammation of the laminae. Clinical signs include foot tenderness progressing to inability to walk, increased digital pulses, and increased temperatur ...

Cattle

A cow hoof is cloven, or divided, into two approximately equal parts, usually called claws. Approximately 95% of lameness in dairy cattle occurs in the feet. Lameness in dairy cows can reduce

milk Milk is a white liquid food produced by the mammary glands of lactating mammals. It is the primary source of nutrition for young mammals (including breastfeeding, breastfed human infants) before they are able to digestion, digest solid food. ...

production and fertility, and cause reproductive problems and suffering. For dairy farm profitability, lameness, behind only infertility and mastitis, is the third most important cow health issue. Hoof trimmers trim and care for bovine hooves, usually dairy cows. Hooves can be trimmed with a sharp knife while the cow is restrained and positioned with ropes. Professional hoof trimmers tend to use angle grinders and some type of hoof trimming crush to make the process quicker and less physically demanding on the hoof trimmer. A hoof trimmer using modern machinery may trim the hooves of more than 10,000 cows per year. The trimmer shapes the hooves to provide the optimal weight-bearing surface. A freshly trimmed hoof may be treated with copper sulfate pentahydrate to prevent foot rot.

Gallery

Masai Giraffe right-rear foot.jpg, Rear foot of a

(no dewclaws) Horse rear hooves.jpg, Rear hooves of a

Tapir hooves.jpg, Malayan tapir hooves: front with four toes, back with three toes Pig cracked hooves.JPG, Cloven hooves of a pig Schafbeine 01.jpg,

Sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

hooves Amneville Bison 27082010 4.jpg, Pointed hooves of a

Cameltoe - Flickr - loufi.jpg, Broad hooves of a

Deer Are The Hoofed Ruminant Mammals Forming The Family Cervidae.jpg, Cloven hooves of a deer Blogcaribou8.jpg, Reindeer hooves Winter horse hooves (5909760691).jpg, Horses' hooves in snow Rind - Hufe - Zoopark Erfurt - 20120409.JPG, Cattle hooves PSM V40 D380 Musk ox hooves.jpg, Muskoxen broad hooves Carcassonne - Dama dama 11.jpg, Padded hooves of a deer Giuseppe Arcimboldo - Study of a Goat's Deformed Hoof - WGA00854.jpg, Padded hooves of a domestic goat Burg Meersburg April 2010 1010942.jpg, Alces alces hooves

In culture

Hooves have historical significance in ceremonies and games. They have been used in burial ceremonies.

Notes

References

{{Authority control Mammal anatomy Ungulates