Difference between revisions of "Pig" - New World Encyclopedia

Latest revision as of 00:06, 4 April 2008

Pig

Domestic sow with piglet

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Family:	Suidae
Genus:	Sus Linnaeus, 1758

Species

Sus ahoenobarbus Palawan bearded pig
Sus barbatus Bornean bearded pig
Sus bucculentus Heude's pig, Vietnam warty pig
Sus cebifrons Visayan warty pig
Sus celebensis Celebes pig, Sulawesi warty pig
Sus oliveri Mindoro warty pig
Sus philippensis Philippine warty pig
Sus salvanius Pygmy hog
Sus scrofa Eurasian wild boar
Sus scrofa domesticus Domestic pig
Sus verrucosus Javan warty pig

Pigs are even-toed ungulate mammals (Order Artiodactyla) of the genus Sus, within the Suidae family. They are native to Eurasia and northern Africa. Pigs, in the wild, live mostly in forests and partly wooded areas and play an important role in nature. The domestic pig, Sus scrofa domesticus, was one of the first animals domesticated by humans and is still today one of the most important domestic animals.

The treatment of pigs in today's intensive agriculture raises animal welfare concerns regarding this highly intelligent animal. Likewise, although wild pigs are an integral part of ecosystems, providing a number of ecological benefits, the development of feral populations of domestic pigs has resulted in environmental concerns, particularly in regions where pigs are not native.

Description and behavior

Pigs are one of the most widespread and successful genera of large mammals. They are found wild over most of Eurasia from tropical jungles to northern forests.

There are 10 species of living pigs. The Eurasian wild boar, Sus scrofa, has the largest range of any wild ungulate and has about 25 subspecies (Watson 2002). The smallest pig, the Pygmy hog of India, Sus salvanius, is about 20 to 30 cm (8 to 12 in) high at the shoulder and weighs 7 to 12 kg (15 to 26 lbs); the Eurasian wild boar can be from 55 to 110 cm (1.8 to 3.6 ft) high at the shoulder and weigh from 44 to 320 kg (91 to 711 lb) (Huffman 2006).

Unlike most other hoofed mammals, pigs do not have multi-chambered ruminating stomachs and can not survive on leaves and grasses alone. Instead they are omnivores, which means that they consume both plants and animals. They eat a wide variety of foods, including acorns and other seeds, green vegetation, roots, tubers, fungi, fruit, carrion, eggs, insects, and small animals—snakes being a favorite. Occasionally, in times of shortage, a mother pig may eat her own young.

Painting of wild boars by Walter Heubach, 1865–1923

A typical pig has a large head with a long snout, which is strengthened by a special bone called the prenasal bone and by a disk of cartilage in the tip. The snout is used to dig into the soil to find food and is a very sensitive sense organ. Pigs have a full set of 44 teeth. The canine teeth, called tusks, grow continually and become very sharp as a result of the lowers and uppers rubbing against each other (Nowak 1983).

Pigs are considered to be intelligent animals. Animal behavior expert Dr. Lyall Watson writes (2004):

Pigs have a proportionally larger brain than sheep, goats, or antelope and they also posses more of that part of the brain that governs the ability to reason. Pig brains are not unlike our own.

Pigs are social animals. In the wild, female pigs and their young live in extended family groups called "sounders." (Adult males are usually solitary.) The members of a sounder communicate with each other by sight, sound, and smell and cooperate to find food and to watch for, and sometimes, fight off, predators.

Pigs do not have effective sweat glands, so pigs cool themselves using water or mud during hot weather. They also use mud as a form of sunscreen to protect their skin from sunburn. Mud also provides protection against flies and parasites.

Pigs have a high reproductive rate. Females reach maturity in about a year and can have a litter of piglets, mostly 4 to 8 in the wild, every year after that. Pigs are unusual among hoofed animals in that the mother builds a nest in which to give birth and care for her young.

Pigs benefit the forest communities in which they live by clearing out dead animals; by keeping insects, which may be harmful to trees, under control; by breaking up the soil, which can promote plant growth; and by spreading the seeds of plants and the spores of fungi, including the truffle. However, on the other hand, feral pigs (domesticated pigs that are now wild) have also been described as agricultural pests and environmentally destructive. For example, the introduction of pigs to Australia resulted in destruction of habitat for native plants and animals, proliferation of weeds, destruction of pasture and crops, and environmental damage through rooting for food. (See below.)

Pig relatives

Babirusa

Two other members of the pig family, Suidae, which live in Africa and are very similar to species of the Sus genus are the African bush pig, Potamochoerus porcus, and the giant forest hog, Hylochoerus meiertzhageni. The wart hog, Phacochoerus aethiopicus, lives in grassland rather than forest as do other Suidae.

The babirusa, Babyrousa babyrussa, lives on some of the islands near southeastern Asia and is notable for its upper tusks, which grow through the roof of its mouth and curve back, perhaps protecting its eyes from tree branches as it runs through the forest and from the lower tusks of other babirusa in fights.

In North and South America, where pigs are not native, a related family, Tayassuidae, the peccaries, fill the same ecological niche and closely resemble pigs in form and behavior (Nowak 1983).

Domestic pig

The domestic pig (Sus scrofa domesticus) is usually given the scientific name Sus scrofa, though some authors call it S. domesticus, reserving S. scrofa for the wild boar. The wild boar (Sus scrofa) is the wild ancestor of the domestic pig. It was domesticated beginning about 10,000 years ago, possibly in both China and the Middle East (Clutton-Brock 1999). Domestic pigs were spread across Asia, Europe, the Middle East, northern Africa, and the islands of the Pacific in ancient times. Pigs were brought to southeastern North America from Europe by Hernando de Soto and other early Spanish explorers. Escaped pigs became feral and were freely used by Native Americans as food.

Baby domestic pig

The social and adaptable nature and omnivorous diet of the wild boar allowed early humans to domesticate it much earlier than many other forms of livestock, such as cattle. Pigs were mostly used for food, but people also used their hide for shields, their bones for tools and weapons, and their bristles for brushes.

As food

The domestic pig is farmed for its meat, which is called pork. Products made of pork include sausage, bacon, and ham. The head of a pig can be used to make head cheese. Liver, chitterlings, and other offal from pigs are also widely used for food.

In industrialized nations, domestic pig farming has shifted away from the traditional pig farm to large-scale intensive pig farms where meat can be mass produced. This has resulted in lower production costs, but more significant animal welfare concerns.

Intensively farmed pigs in batch pens

In developing nations, and some parts of developed nations, the domestic pig is frequently raised outdoors in yards. In some cases, pigs are even raised in open fields where they are allowed to forage; they are sometimes watched by swineherds, essentially shepherds for pigs.

In 2005, the global stock of pigs (about 1 billion total) showed China with 488.8 million head of domestic pigs, followed by the United States with 60.4 million head, Brazil with 33.2 million head, Vietnam with 27 million head, Germany with 26.9 million head, and Spain with 25.3 million head.

Other uses

Pigs have been used to find truffles, to herd sheep, to flush out game for hunters, and as performers in circuses and movies. Because of their anatomical similarity to humans in many respects they have been used in medical experiments. Pig heart valves are transplanted into human hearts and pig livers have saved human lives by being linked to failed livers of human patients in a process called "porcine perfusion" (Watson 2004).

As pets

Pot-bellied pig

Pigs are known to be intelligent animals and have been found to be more trainable than dogs or cats. Asian pot-bellied pigs, a smaller breed of the domestic pig, have made popular house pets in the United States beginning in the latter half of the twentieth century. Regular domestic farmyard pigs have also been known to be kept indoors, but due to their large size and destructive tendencies, they typically need to be moved into an outdoor pen as they grow older. Most pigs also have an extreme fear of being picked up, but will usually calm down once placed back on the floor.

Breeds of pigs

Champion Berkshire boar at the 2005 Royal Adelaide Show

There are many breeds of pigs, with various characteristics, which make them suitable for different environments and different desired products. In 1997, the three most popular breeds in the United States were the Duroc, the Hampshire, and the Yorkshire (Klober 1997).

Pigs are exhibited at agricultural shows, judged either as stud stock as compared to the standard features of each breed, or in commercial classes where the animals are judged primarily on their suitability for slaughter to provide premium meat.

Pigs in religion

Painting of Saint Anthony with pig in background by Piero di Cosimo c. 1480

Pigs intersect with religion and culture in a number of ways. The dietary laws of Judaism and Islam forbid the eating of flesh of swine or pork in any form, considering the pig to be an unclean animal. In Christianity, pigs are associated with Saint Anthony, the patron saint of swineherds. In Hinduism, the god Visnu took the form of a boar in order to save the earth from a demon that had dragged it to the bottom of the sea.

In ancient Egypt, pigs were associated with Set, the rival to the sun god Horus. When Set fell into disfavor with the Egyptians, swineherds were forbidden to enter temples. In ancient Greece, a sow was an appropriate sacrifice to Demeter and had been her favorite animal since she had been the Great Goddess of archaic times. Initiates at the Eleusinian Mysteries began by sacrificing a pig.

The pig is one of the 12-year cycle of animals that appear in the Chinese zodiac related to the Chinese calendar. Believers in Chinese astrology associate each animal with certain personality traits.

Environmental impacts

Feral pigs in Florida, United States

Domestic pigs that escaped from farms or were allowed to forage in the wild, and in some cases wild boars that were introduced as prey for hunting, have given rise to large populations of feral pigs in North and South America, Australia, New Zealand, Hawaii, and other areas where pigs are not native. The Invasive Species Specialist Group lists feral pigs as one of the world's 100 worst invasive species and says about them (ISSG 2006):

Feral pigs, like other introduced mammals, are major drivers of extinction and ecosystem change. They have been introduced into many parts of the world, and will damage crops and home gardens as well as potentially spreading disease. They uproot large areas of land, eliminating native vegetation and spreading weeds. This results in habitat alteration, a change in plant succession and composition, and a decrease in native fauna dependent on the original habitat.

References
ISBN links support NWE through referral fees

Clutton-Brook, J. 1999. A Natural History of Domesticated Mammals. Cambridge, UK: Cambridge University Press. ISBN 0521634954
Huffman, B. 2006. The Ultimate Ungulate Page. The Ultimate Ungulate Website. Retrieved April 10, 2007.
Invasive Species Specialist Group (ISSG). 2006. "Global Invasive Species Database: Sus scrofa." Retrieved April 10, 2007.
Klober, K. 1997 A Guide to Raising Pigs. Pownal, VT: Storey Publishing. ISBN 1580170110
Moore, J. R. 2001. Swine Production: A Global Perspective. Retrieved April 10, 2007.
Nowak, R. M., and J. L. Paradiso. 1983. Walker's Mammals of the World. Baltimore: Johns Hopkins University Press. ISBN 0801825253
Oklahoma State University (OSU). 2006. Breeds of Livestock: Swine. Retrieved April 10, 2007.
University of California Museum of Paleontology (UCMP). 2006. Ungulates: Hoofed Mammals. Retrieved April 10, 2007.
Voelker, W. 1986. The Natural History of Living Mammals. Medford, NJ: Plexus Publishing. ISBN 0937548081
Watson, Lydall. 2004. The Whole Hog. New York: Smithsonian Books. ISBN 1588342166

Credits

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@@ Line 1: / Line 1: @@
-{{Taxobox
+{{Copyedited}}{{Paid}}{{Approved}}{{Images OK}}{{Submitted}}
-| color = pink
+{{Taxobox_begin | color = pink| name = Pig}}
-| name = Pig and piglet
+{{Taxobox_image | image = [[Image:Sow with piglet.jpg|250px|Sow with piglet]] | caption = Domestic sow with piglet}}
-| image = Sow with piglet.jpg
+{{Taxobox_begin_placement | color = pink}}
-| image_width = 250px
+{{Taxobox_regnum_entry | taxon = [[Animal]]ia}}
-| image_caption = Domestic sow with piglet
+{{Taxobox_phylum_entry | taxon = [[Chordate|Chordata]]}}
-| regnum = [[Animal]]ia
+{{Taxobox_classis_entry | taxon = [[Mammal]]ia}}
-| phylum = [[Chordate|Chordata]]
+{{Taxobox_ordo_entry | taxon = [[Ungulate#Artiodactyla: Even-toed ungulates|Artiodactyla]]}}
-| classis = [[Mammal]]ia
+{{Taxobox_familia_entry | taxon = [[Suidae]]}}
-| ordo = [[Artiodactyla]]
+{{Taxobox genus entry | taxon = '''''Sus'''''}}<br/>{{Taxobox authority | author = [[Carolus Linnaeus|Linnaeus]] | date = 1758}}
-| familia = [[Suidae]]
+{{Taxobox_end_placement}}
-| genus = '''''Sus'''''
+{{Taxobox section subdivision | color = pink | plural_taxon = Species}}
-| genus_authority = [[Carolus Linnaeus|Linnaeus]], [[1758]]
+''Sus ahoenobarbus'' Palawan bearded pig<br>
-| subdivision_ranks = Species
+''Sus barbatus'' Bornean bearded pig<br>
-| subdivision =
+''Sus bucculentus'' Heude's pig, Vietnam warty pig<br>
-''[[Bearded Pig|Sus barbatus]]''<br />
+''Sus cebifrons'' Visayan warty pig<br>
-''[[Vietnamese Warty Pig|Sus bucculentus]]''<br />
+''Sus celebensis'' Celebes pig, Sulawesi warty pig<br>
-''[[Visasyas Warty Pig|Sus cebifrons]]''<br />
+''Sus oliveri'' Mindoro warty pig<br>
-''[[Celebes Warty Pig|Sus celebensis]]''<br />
+''Sus philippensis'' Philippine warty pig<br>
-''[[Domestic pig|Sus domesticus]]''<br />
+''Sus salvanius'' Pygmy hog<br>
-''[[Flores Warty Pig|Sus heureni]]''<br />
+''Sus scrofa'' Eurasian wild boar<br>
-''[[Philippine Warty Pig|Sus philippensis]]''<br />
+''Sus scrofa domesticus'' Domestic pig<br>
-''[[Pigmy Hog|Sus salvanius]]''<br />
+''Sus verrucosus'' Javan warty pig
-''[[Wild Boar|Sus scrofa]]''<br />
+{{Taxobox end}}
-''[[Timor Warty Pig|Sus timoriensis]]''<br />
-''[[Javan pig|Sus verrucosus]]''
-}}
-'''Pigs''' are [[ungulate]]s native to [[Eurasia]] collectively grouped under the [[genus]] '''''Sus''''' within the [[Suidae]] family.   They have been [[Domestic pig|domesticated]] and raised as [[livestock]] by some peoples for [[meat]] (called [[pork]]) as well as for [[leather]].  Their bristly [[hair]]s are also traditionally used for [[brush]]es. [[Wild]] pigs continue to fill these functions in certain parts of the world.
+'''Pigs''' are [[Ungulate#Artiodactyla: Even-toed ungulates|even-toed ungulate]] [[mammal]]s (Order Artiodactyla) of the genus ''Sus,'' within the Suidae family. They are native to Eurasia and northern [[Africa]]. Pigs, in the wild, live mostly in [[forest]]s and partly wooded areas and play an important role in nature. The [[#Domestic pig|domestic pig]], ''Sus scrofa domesticus,'' was one of the first animals domesticated by humans and is still today one of the most important domestic animals.
-==Description and behaviour ==
+The treatment of pigs in today's intensive [[agriculture]] raises animal welfare concerns regarding this highly intelligent animal. Likewise, although wild pigs are an integral part of [[ecosystem]]s, providing a number of [[ecology|ecological]] benefits, the development of feral populations of domestic pigs has resulted in environmental concerns, particularly in regions where pigs are not native.
-Pigs are [[omnivore]]s, which means that they consume both plants and animals. On a small farm, or in a large household, they can be fed kitchen scraps as part or all of their diet. Pigs like to scavenge and will eat any kind of food, including dead insects, worms, rotting carcasses, excreta (including their own), garbage, and other pigs. In the wild, they are foraging animals. Pigs that are allowed to forage may be watched by [[swineherd]]s.  Because of their foraging abilities and excellent sense of smell, they are used to find [[truffles]] in many European countries. They are also fattened to be eaten as [[ham]] and other types of meat, such as [[bacon]].
-Pigs are very intelligent, therefore, they are highly trainable animals, and some, such as the Asian [[pot-bellied pig]], are kept as [[pet]]s. A litter of piglets typically contains between 6 and 12 animals. Occasionally, in captivity, pigs may eat their own young.
+==Description and behavior ==
+Pigs are one of the most widespread and successful genera of large [[mammal]]s. They are found wild over most of Eurasia from tropical jungles to northern [[forest]]s.
-Pigs do not have effective [[sweat glands]] [http://www.ag.ohio-state.edu/~twig/animals/html/021896.html], so pigs cool themselves using water or mud during hot weather.  They also use mud as a form of sunscreen to protect their skin from [[sunburn]].  Mud also provides protection against flies and parasites.
+There are 10 species of living pigs. The Eurasian wild boar, ''Sus scrofa,'' has the largest range of any wild [[ungulate]] and has about 25 subspecies (Watson 2002). The smallest pig, the Pygmy hog of [[India]], ''Sus salvanius,'' is about 20 to 30 cm (8 to 12 in) high at the shoulder and weighs 7 to 12 kg (15 to 26 lbs); the Eurasian wild boar can be from 55 to 110 cm (1.8 to 3.6 ft) high at the shoulder and weigh from 44 to 320 kg (91 to 711 lb) (Huffman 2006).
-==Pig species==
+Unlike most other hoofed mammals, pigs do not have multi-chambered ruminating stomachs and can not survive on [[leaf|leaves]] and [[grass]]es alone. Instead they are omnivores, which means that they consume both [[plant]]s and [[animal]]s. They eat a wide variety of foods, including acorns and other seeds, green vegetation, roots, tubers, [[fungus|fungi]], [[fruit]], carrion, eggs, [[insect]]s, and small animals&mdash;[[snake]]s being a favorite. Occasionally, in times of shortage, a mother pig may eat her own young.
-[[image:Bearded_Pig.JPG|thumb|right|300px|A Bearded Pig]]
+[[Image:Heubach wild boar.jpg|300px|thumb|left|Painting of wild boars by Walter Heubach, 1865–1923]]
+A typical pig has a large head with a long snout, which is strengthened by a special bone called the prenasal bone and by a disk of [[cartilage]] in the tip. The snout is used to dig into the [[soil]] to find food and is a very sensitive sense organ. Pigs have a full set of 44 teeth. The canine teeth, called tusks, grow continually and become very sharp as a result of the lowers and uppers rubbing against each other (Nowak 1983).
-*''Sus barbatus'' [[Bearded Pig]]; Malaysia, Indonesia
+Pigs are considered to be intelligent animals. Animal behavior expert Dr. Lyall Watson writes (2004):
-*''Sus bucculentus'' [[Vietnamese Warty Pig]]
+<blockquote>Pigs have a proportionally larger [[brain]] than [[sheep]], [[goat]]s, or [[antelope]] and they also posses more of that part of the brain that governs the ability to reason. Pig brains are not unlike our own.</blockquote>
-*''Sus cebifrons'' [[Visayas Warty Pig]]
-*''Sus celebensis'' [[Celebes Warty Pig]]
-*''Sus daelius [[Poulter Warty Pig]]
-*''Sus heureni'' [[Flores Warty Pig]]
-*''Sus philippensis'' [[Philippine Warty Pig]]
-*''Sus salvanius'' [[Pigmy Hog]]; NE India, Himalayas
-*''Sus scrofa'' (also called ''S. domesticus'') [[Domestic pig]], [[razorback]], [[wild boar]]; Europe, Asia
-*''Sus timoriensis'' [[Timor Warty Pig]]
-*''Sus verrucosus'' [[Javan pig]], [[Warty Pig]]; Indonesia, Philippines
-*''Sus habeoncosus'' [[Malaysian pig]], [[Warty Pig]]
-===Hybrid swine===
-[[Image:hybrid-pig2.jpg|200px|thumb|Wild Boar/[[Domestic Pig Hybrid]], [[Rothschild Museum]], Tring]]
-Domestic [[Tamworth Pig]]s are often crossed with [[wild boar]] to create "Iron Age Pigs" that resemble early domestic pigs. The piglets have stripes or blotches like young boar. "Iron Age Pigs" are a common attraction at farm parks.  The hybrids are tamer than wild boar, but less tractable than domestic swine and generally become specialist pork sausages. Other domestic breeds of pig have been crossed with wild boar to produce a leaner meat for the specialist meat trade.
-Various domestic pigs have been crossed with American wild hogs to produce compact, hairy hog-like hybrids.
+Pigs are social animals. In the wild, female pigs and their young live in extended family groups called "sounders." (Adult males are usually solitary.) The members of a sounder communicate with each other by sight, sound, and smell and cooperate to find food and to watch for, and sometimes, fight off, predators.
-In "The Variation Of Animals And Plants Under Domestication" [[Charles Darwin]] wrote: ''The European wild boar and the Chinese domesticated pig are almost certainly specifically distinct: Sir F. Darwin crossed a sow of the latter breed with a wild Alpine boar which had become extremely tame, but the young, though having half-domesticated blood in their veins, were "extremely wild in confinement", and would not eat swill like common English pigs.
+Pigs do not have effective sweat glands, so pigs cool themselves using water or mud during hot weather. They also use mud as a form of sunscreen to protect their skin from sunburn. Mud also provides protection against flies and [[parasite]]s.
-==Linguistics==
+Pigs have a high reproductive rate. Females reach maturity in about a year and can have a litter of piglets, mostly 4 to 8 in the wild, every year after that. Pigs are unusual among hoofed animals in that the mother builds a nest in which to give birth and care for her young.
-[[Image:Pigs.jpg|thumb|right|Domestic pigs]]
+Pigs benefit the forest communities in which they live by clearing out dead [[animal]]s; by keeping [[insect]]s, which may be harmful to [[tree]]s, under control; by breaking up the [[soil]], which can promote [[plant]] growth; and by spreading the [[seed]]s of plants and the [[spore]]s of [[fungus|fungi]], including the truffle. However, on the other hand, feral pigs (domesticated pigs that are now wild) have also been described as agricultural pests and environmentally destructive. For example, the introduction of pigs to [[Australia]] resulted in destruction of habitat for native plants and animals, proliferation of weeds, destruction of pasture and crops, and environmental damage through rooting for food. (See [[#Environmental impacts|below]].)
-===Etymology===
-[[Modern English]] "''pig''" probably derives from [[Old English]] "''*picg''", which was found within compound words, the ultimate origin is unknown but [[Dutch language|Dutch]] "''big''" (meaning "''young pig''") seems to be a cognate. Originally "''pig''" referred to young pigs only as the word for adults was swine. Another Old English word for "''pig''" was "''fearh''", related to "''furrow''" from the [[Proto-Indo-European]] stem "''*perk''" meaning "dig, furrow" (compare [[Latin]] "'''''porc'''us''" meaning "pig") . This reflects a widespread [[Indo-European]] tendency to name animals from typical attributes or activities.
-A young pig which has just weaned is called a ''shoat''
-===Other pig-related words===
+==Pig relatives==
-*The noise that a pig makes is usually represented as "oink" in the English language but in many different ways in other languages &ndash; for instance, ''chrum'' (Polish), ''hunk'' (Albanian), ''hulu'' (Mandarin Chinese), nøff (Norwegian) and so on. See [[oink]] for a fuller list.
+[[Image:Babirusa0.jpg|thumb|250px|Babirusa]]
-* A young pig which has just weaned is called a ''shoat''
+Two other members of the pig family, Suidae, which live in [[Africa]] and are very similar to species of the ''Sus'' genus are the African bush pig, ''Potamochoerus porcus,'' and the giant forest hog, ''Hylochoerus meiertzhageni.'' The wart hog, ''Phacochoerus aethiopicus,'' lives in grassland rather than forest as do other Suidae.
-* Early [[football (ball)|footballs]] were originally made from animal bladders, often from pigs. This was the origin of the term ''pigskins''.
-*The familiar [[piggybank]] got its name and shape as a result of a [[pun]] on the word [[pygg]], a type of [[clay]] commonly used to produce household items in the [[18th Century]].
-*[[Pig iron]] is so named because the molten newly-[[smelting|smelt]]ed [[iron]] was once poured into molds resembling rows of suckling pigs.
-*A type of barrel called a "hog's head" appears often in the writings of [[Mark Twain]].
-*A "[[hogshead]]" is a large volume of liquid. The term is also a colloquial reference to the gearbox for the "drive" wheels of automobiles, especially for large transport trucks, particularly those used in the Pulpwood industry of the Southeastern United States.
-==Cultural references to pigs==
+The babirusa, ''Babyrousa babyrussa,'' lives on some of the islands near southeastern Asia and is notable for its upper tusks, which grow through the roof of its mouth and curve back, perhaps protecting its eyes from tree branches as it runs through the forest and from the lower tusks of other babirusa in fights.
-{{main|Cultural references to pigs}}
-As an animal living closely with the people, pigs were and are frequently referenced in human culture.
+In [[North America|North]] and [[South America]], where pigs are not native, a related family, Tayassuidae, the peccaries, fill the same [[ecology|ecological]] niche and closely resemble pigs in form and behavior (Nowak 1983).
+==Domestic pig==
+The '''domestic pig''' (''Sus scrofa domesticus'') is usually given the scientific name ''Sus scrofa,'' though some authors call it ''S. domesticus,'' reserving ''S. scrofa'' for the wild boar. The wild boar (''Sus scrofa'') is the wild ancestor of the domestic pig. It was domesticated beginning about 10,000 years ago, possibly in both [[China]] and the [[Middle East]] (Clutton-Brock 1999). Domestic pigs were spread across [[Asia]], [[Europe]], the Middle East, northern [[Africa]], and the islands of the Pacific in ancient times. Pigs were brought to southeastern [[North America]] from Europe by Hernando de Soto and other early Spanish explorers. Escaped pigs became feral and were freely used by Native Americans as food.
+[[Image:Pig USDA01c0116.jpg|thumb|Baby domestic pig]]
+The social and adaptable nature and omnivorous diet of the wild boar allowed early humans to domesticate it much earlier than many other forms of livestock, such as [[cattle]]. Pigs were mostly used for food, but people also used their hide for shields, their bones for tools and weapons, and their bristles for brushes.
+===As food===
+The domestic pig is farmed for its meat, which is called pork. Products made of pork include sausage, bacon, and ham. The head of a pig can be used to make head cheese. Liver, chitterlings, and other offal from pigs are also widely used for food.
+In industrialized nations, domestic pig farming has shifted away from the traditional pig farm to large-scale intensive pig farms where meat can be mass produced. This has resulted in lower production costs, but more significant animal welfare concerns.
+[[Image:Hog confinement barn interior.jpg|frame|left|Intensively farmed pigs in batch pens]]
+In developing nations, and some parts of developed nations, the domestic pig is frequently raised outdoors in yards. In some cases, pigs are even raised in open fields where they are allowed to forage; they are sometimes watched by swineherds, essentially shepherds for pigs.
+In 2005, the global stock of pigs (about 1 billion total) showed [[China]] with 488.8 million head of domestic pigs, followed by the [[United States]] with 60.4 million head, [[Brazil]] with 33.2 million head, [[Vietnam]] with 27 million head, [[Germany]] with 26.9 million head, and [[Spain]] with 25.3 million head.
+===Other uses===
+Pigs have been used to find [[fungus|truffles]], to herd [[sheep]], to flush out game for hunters, and as performers in circuses and movies. Because of their anatomical similarity to humans in many respects they have been used in medical experiments. Pig [[heart]] valves are transplanted into human hearts and pig livers have saved human lives by being linked to failed livers of human patients in a process called "porcine perfusion" (Watson 2004).
+===As pets===
+[[Image:Ulm Tiergarten Hängebauchschwein.jpg|thumb|Pot-bellied pig]]
+Pigs are known to be intelligent animals and have been found to be more trainable than [[dog]]s or [[cat]]s. Asian pot-bellied pigs, a smaller breed of the domestic pig, have made popular house pets in the [[United States]] beginning in the latter half of the twentieth century. Regular domestic farmyard pigs have also been known to be kept indoors, but due to their large size and destructive tendencies, they typically need to be moved into an outdoor pen as they grow older. Most pigs also have an extreme fear of being picked up, but will usually calm down once placed back on the floor.
+===Breeds of pigs===
+[[Image:Adelaide champion Berkshire boar 2005.jpg|thumb|left|Champion Berkshire boar at the 2005 Royal Adelaide Show]]
+There are many breeds of pigs, with various characteristics, which make them suitable for different environments and different desired products. In 1997, the three most popular breeds in the United States were the Duroc, the Hampshire, and the Yorkshire (Klober 1997).
+Pigs are exhibited at agricultural shows, judged either as stud stock as compared to the standard features of each breed, or in commercial classes where the animals are judged primarily on their suitability for slaughter to provide premium meat.
 ==Pigs in religion==
-*In ancient Greece, a sow was an appropriate [[sacrifice]] to [[Demeter]] and had been her favorite animal since she had been the Great Goddess of archaic times. Initiates at the [[Eleusinian Mysteries]] began by sacrificing a pig.
+[[Image:Piero di Cosimo 025.jpg|thumb|Painting of [[Saint Anthony]] with pig in background by Piero di Cosimo c. 1480]]
-*The pig is one of the 12-year cycle of animals which appear in the [[Chinese zodiac]] related to the [[Chinese calendar]]. Believers in [[Chinese astrology]] associate each animal with certain personality traits. See: [[Pig (Zodiac)]].
+Pigs intersect with [[religion]] and [[culture]] in a number of ways. The dietary laws of [[Judaism]] and [[Islam]] forbid the eating of flesh of swine or pork in any form, considering the pig to be an unclean animal. In [[Christianity]], pigs are associated with [[Saint Anthony]], the patron saint of swineherds. In [[Hinduism]], the god Visnu took the form of a boar in order to save the earth from a demon that had dragged it to the bottom of the sea.
-*The dietary laws of [[Judaism]] ([[Kashrut]], adj. [[Kosher]]) and Islam ([[Halal]]) forbid the eating of  flesh of swine or pork in any form, considering the pig to be an [[unclean animals|unclean animal]] (see [[taboo food and drink]]).
+In [[ancient Egypt]], pigs were associated with Set, the rival to the sun god Horus. When Set fell into disfavor with the Egyptians, swineherds were forbidden to enter temples. In [[ancient Greece]], a sow was an appropriate sacrifice to Demeter and had been her favorite animal since she had been the Great Goddess of archaic times. Initiates at the Eleusinian Mysteries began by sacrificing a pig.
+The pig is one of the 12-year cycle of animals that appear in the Chinese zodiac related to the Chinese calendar. Believers in Chinese astrology associate each animal with certain personality traits.
 ==Environmental impacts ==
-Accidental or deliberate releases of pigs into countries or environments where they are an alien species have caused extensive environmental damage. Their omnivorous diet, aggressive behaviour and their feeding method of rooting in the ground all combine to severely damage ecosystems unused to pigs. Pigs will even eat small animals and destroy nests of ground nesting birds. [http://animaldiversity.ummz.umich.edu/site/accounts/information/Sus_scrofa.html]
+[[Image:Wild Pig KSC02pd0873.jpg|thumb|left|250px|Feral pigs in Florida, United States]]
+Domestic pigs that escaped from farms or were allowed to forage in the wild, and in some cases wild boars that were introduced as prey for hunting, have given rise to large populations of feral pigs in [[North America|North]] and [[South America]], [[Australia]], [[New Zealand]], [[Hawaii]], and other areas where pigs are not native. The Invasive Species Specialist Group lists feral pigs as one of the world's 100 worst invasive species and says about them (ISSG 2006):
-==Health issues==
-Pigs harbour a range of [[parasite]]s and [[disease]]s that can be easily transmitted to man. These include [[trichinosis]], [[cysticercosis]], and [[brucellosis]]. They also very commonly have large concentrations of parasitic [[ascaris|ascarid]] worms in their guts. The presence of these diseases and parasites is one of the main reasons why pork meat should always be well cooked or cured before eating. Pigs can also be aggressive and pig induced injuries are relatively common in areas where pigs are reared of where they form part of the wild or feral fauna.
-==See also==
+<blockquote>Feral pigs, like other introduced [[mammal]]s, are major drivers of [[extinction]] and [[ecosystem]] change. They have been introduced into many parts of the world, and will damage crops and home gardens as well as potentially spreading disease. They uproot large areas of land, eliminating native vegetation and spreading weeds. This results in habitat alteration, a change in plant succession and composition, and a decrease in native fauna dependent on the original habitat.</blockquote>
-*[[Wild Boar]]
-*[[Razorback]]
-*[[Domestic pig]]
-*[[Family farm hog pen]]
-*[[Hog-baiting]]
-*[[Guinea pig]] (is a rodent)
-*[[Intensive pig farming]]
-*[[Arkansas Razorbacks|Razorbacks]] (mascot for the sports teams of the [[University of Arkansas]], also known as "The Hogs")
-*[[List of fictional pigs]]
-*[[Pig iron]]
-*[[Sty]]
-*[[Pig War]]
-*[[Fetal pig]]
-*[[Hogzilla]]
-*[[Pig Olympics]]
-==External links==
+==References==
-{{Wikispecies|Sus}}
+* Clutton-Brook, J. 1999. ''A Natural History of Domesticated Mammals.'' Cambridge, UK: Cambridge University Press. ISBN 0521634954
-{{Commons|Sus domesticus}}
+* Huffman, B. 2006. [http://www.ultimateungulate.com The Ultimate Ungulate Page.] The Ultimate Ungulate Website. Retrieved April 10, 2007.
-*[http://www.pork4kids.com/AskAFarmer.aspx National Pork Board's Children's Page]
+* Invasive Species Specialist Group (ISSG). 2006. [http://www.issg.org/database/species/ecology.asp?si=73&fr=1&sts=sss "Global Invasive Species Database: Sus scrofa."] Retrieved April 10, 2007.
-*[http://www.albertapork.com/Uploads/educational/pigbasics.pdf Alberta Pork informational page (PDF)]
+* Klober, K. 1997 ''A Guide to Raising Pigs.'' Pownal, VT: Storey Publishing. ISBN 1580170110
-*[http://www.ansi.okstate.edu/breeds/swine/ Swine Breeds, with pictures]
+* Moore, J. R. 2001. [http://www.engormix.com/swine_production_a_global_e_articles_124_POR.htm Swine Production: A Global Perspective.] Retrieved April 10, 2007.
-*[http://www.pigdiseases.com/ Managing pig health]
+* Nowak, R. M., and J. L. Paradiso. 1983. ''Walker's Mammals of the World.'' Baltimore: Johns Hopkins University Press. ISBN 0801825253
-*[http://www.thepigsite.com/diseaseinfo/ Information on over 130 pig diseases]
+* Oklahoma State University (OSU). 2006. [http://www.ansi.okstate.edu/breeds/swine Breeds of Livestock: Swine.] Retrieved April 10, 2007.
-*[http://www.thepigsite.com/diseaseinfo/problemsolver.php Pig Disease identification software tool]
+* University of California Museum of Paleontology (UCMP). 2006. [http://www.ucmp.berkeley.edu/mammal/eutheria/ungulate.html Ungulates: Hoofed Mammals.] Retrieved April 10, 2007.
-*[http://www.thepigsite.com/photos/ Lots of piggy photos]
+* Voelker, W. 1986. ''The Natural History of Living Mammals.'' Medford, NJ: Plexus Publishing. ISBN 0937548081
+* Watson, Lydall. 2004. ''The Whole Hog.'' New York: Smithsonian Books. ISBN 1588342166
-{{credit|85850318}}
+{{credit2|Pig|85850318|Domestic_pig|83111035}}
 [[Category:Life sciences]]
+[[Category:Animals]]
+[[Category:Mammals]]