The hoof (plural: hooves) is the tip of a
toe
Toes are the digits (fingers) of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being ''digitigrade''. Humans, and other animals that walk on the soles of their feet, are described as being ''plant ...
of an
ungulate
Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, cam ...
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
, 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''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...
covering.
Artiodactyl
The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poster ...
s are even-toed ungulates, species whose feet have an even number of digits, yet the ruminants with two digits, are the most numerous, e.g.
giraffe
The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa''. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes were thought to be one species, ''Giraffa camelopardalis ...
,
deer
Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...
,
bison
Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised.
Of the two surviving species, the American bison, ''B. bison'', found only in North Ame ...
,
cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...
,
goat
The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically 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 a ...
, and
sheep
Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals 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 domesticated s ...
.
The feet of
perissodactyl
Odd-toed ungulates, mammals which constitute the taxonomic order Perissodactyla (, ), are animals—ungulates—who have reduced the weight-bearing toes to three (rhinoceroses and tapirs, with tapirs still using four toes on the front legs) o ...
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 million y ...
, the
rhinoceros
A rhinoceros (; ; ), commonly abbreviated to rhino, is a member of any of the five extant species (or numerous extinct species) of odd-toed ungulates in the family Rhinocerotidae. (It can also refer to a member of any of the extinct species o ...
, and the
tapir
Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America, with one species inhabit ...
.
Hooves are limb structures restricted to
placenta
The placenta 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 the physically separate mater ...
l mammals, which have long pregnancies; however, the
marsupial
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...
''
Chaeropus
''Chaeropus'', known as the pig-footed bandicoots, is a genus of small mammals that became extinct during the 20th century. They were unique marsupials, of the order Peramelemorphia (bandicoots and bilbies), with unusually thin legs, yet were a ...
'' had hooves.
Description
![Horse hoof wild bare sagittal](https://upload.wikimedia.org/wikipedia/commons/3/3e/Horse_hoof_wild_bare_sagittal.jpg)
The hoof surrounds the distal end of the
second phalanx, the
distal phalanx
The phalanges (singular: ''phalanx'' ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones.
...
, 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 tarsal bones, found in the foot. Its name derives from the human bone's resemblance to a small boat, caused by the ...
.
The hoof consists of the
hoof wall
The hoof (plural: hooves) is the tip of a toe of an ungulate mammal, which is covered and strengthened with a thick and horny keratin covering. Artiodactyls are even-toed ungulates, species whose feet have an even number of digits, yet the rumi ...
, the bars of the hoof, the sole and
frog
A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...
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 ungulate
The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poster ...
s (such as
sheep
Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals 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 domesticated s ...
,
goat
The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically 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 a ...
s,
deer
Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...
,
cattle
Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...
,
bison
Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised.
Of the two surviving species, the American bison, ''B. bison'', found only in North Ame ...
and
pig
The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus s ...
s) have two main hooves on each foot, together called a
cloven hoof
A cloven hoof, cleft hoof, divided hoof or split hoof is a hoof split into two toes. This is found on members of the mammalian order Artiodactyla. Examples of mammals that possess this type of hoof are cattle, deer, pigs, antelopes, gazelles, go ...
.
[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 digit ...
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
giraffe
The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa''. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes were thought to be one species, ''Giraffa camelopardalis ...
s and
pronghorn
The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American a ...
s) have no dewclaws.
In some so-called "cloven-hooved" animals, such as
camel
A camel (from: la, camelus and grc-gre, κάμηλος (''kamēlos'') from Hebrew or Phoenician: גָמָל ''gāmāl''.) is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. C ...
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 ungulate
Odd-toed ungulates, mammals which constitute the taxonomic order Perissodactyla (, ), are animals—ungulates—who have reduced the weight-bearing toes to three (rhinoceroses and tapirs, with tapirs still using four toes on the front legs) ...
s (
equid
Equidae (sometimes known as the horse family) is the taxonomic family of horses and related animals, including the extant horses, asses, and zebras, and many other species known only from fossils. All extant species are in the genus '' Equus'', w ...
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
tapir
Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America, with one species inhabit ...
is a special case, having three toes on each hind foot and four toes on each front foot.
Management
![Naal on bull hooves 1](https://upload.wikimedia.org/wikipedia/commons/3/35/Naal_on_bull_hooves_1.jpg)
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 fabricated 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 toen ...
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
The horse industry, or equine industry, is the economic activity associated with horses. This includes core agribusiness activities related to the use, possession or ownership of horses, as well as leisure activities and related economic activity ...
.
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 of the 3rd digit ...
care include hoof cracks, thrush, abscesses and
laminitis
Laminitis is a disease that affects the feet of ungulates and is found mostly in horses and cattle. Clinical signs include foot tenderness progressing to inability to walk, increased digital pulses, and increased temperature in the hooves. Sever ...
.
Cattle
![Klauenpflege Kuh 9783](https://upload.wikimedia.org/wikipedia/commons/0/0b/Klauenpflege_Kuh_9783.jpg)
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 mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digestion, digest solid food. Immune factors and immune ...
production and fertility, and cause reproductive problems and suffering. For dairy farm profitability, lameness, behind only infertility and
mastitis
Mastitis is inflammation of the breast or udder, usually associated with breastfeeding. Symptoms typically include local pain and redness. There is often an associated fever and general soreness. Onset is typically fairly rapid and usually occurs ...
, is the third most important cow health issue.
Hoof trimmers trim and care for bovine hooves, usually
dairy cows
Dairy cattle (also called dairy cows) are cattle bred for the ability to produce large quantities of milk, from which dairy products are made. Dairy cattle generally are of the species ''Bos taurus''.
Historically, little distinction was mad ...
. Hooves can be trimmed with a sharp knife while the cow is restrained and positioned with ropes. Professional hoof-trimming tend to use
angle grinder
An angle grinder, also known as a side grinder or disc grinder, is a handheld power tool used for grinding (abrasive cutting) and polishing. Although developed originally as tools for rigid abrasive discs, the availability of an interchangeable ...
s and of 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
Foot rot, or infectious pododermatitis, is a hoof infection commonly found in sheep, goats, and cattle. As the name suggests, it rots away the foot of the animal, more specifically the area between the two toes of the affected animal. It is extreme ...
.
Gallery
File:Masai Giraffe right-rear foot.jpg, Rear foot of a giraffe
The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa''. It is the tallest living terrestrial animal and the largest ruminant on Earth. Traditionally, giraffes were thought to be one species, ''Giraffa camelopardalis ...
(no dewclaws)
File:Horse rear hooves.jpg, Rear hooves of a 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 million y ...
File:Tapir hooves.jpg, Malayan tapir
The Malayan tapir (''Tapirus indicus''), also called Asian tapir, Asiatic tapir and Indian tapir, is the only tapir species native to Southeast Asia from the Malay Peninsula to Sumatra. It has been listed as Endangered on the IUCN Red List since ...
hooves: front with four toes, back with three toes
In culture
Hooves have historical significance in ceremonies and games. They have been used in burial ceremonies.
See also
*
Claw
A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or tarsus ...
*
Hoof glue Hoof glue is a form of animal glue made by boiling down the hooves of ungulates into partially hydrolyzed keratin. It is not to be confused with hide glue.
History
Hoof glue applications include stiffening bow strings, adhering fabric to wood, ...
*
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 of the 3rd digit ...
*
Nail (anatomy)
A nail is a claw-like plate found at the tip of the Finger, fingers and Toe, toes on most primates. Nails correspond to the claws found in other animals. Fingernails and toenails are made of a tough protective protein called alpha-keratin, which i ...
Notes
References
{{Authority control
Mammal anatomy