Difference between revisions of "Pig" - New World Encyclopedia

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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 members of the genus Sus, within the Suidae family. They are even-toed ungulates, hoofed mammals, native to Eurasia and Africa. Pigs, in the wild, live mostly in forests and savannas 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.

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. The Eurasian wild boar, Sus scrofa, has the largest range of any wild ungulate (Watson 2002). There are 10 species of living pigs and many subspecies. 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) while 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.

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 canines, called tusks, grow continually and become very sharp by the lowers and uppers rubbing against each other (Nowak 1983).

Pigs are very intelligent. Animal behavior expert Dr. Lyall Watson writes (Watson 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 they live in extended family groups called "sounders". 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.

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. It was domesticated beginning about 10,000 years ago, possibally in both China and the Middle East (Clutton-Brock 1999). Domestic pigs 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 De Soto and other early Spanish explorers. Escaped pigs became feral and were freely used by Native Americans as food. The distinction between wild and domestic animals is slight, and domestic pigs have become feral in many parts of the world (for example, New Zealand and parts of North America) and have caused substantial environmental damage.

The 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 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 pigs 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.

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 watched by swineherds, essentially shepherds for pigs.

In 2005, the global stock of pigs (about 1,000 million 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.

Intensively farmed pigs in batch pens

As pets

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 20th 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

Pigs are exhibited at agricultural shows, judged either as stud stock 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.

File:Pigs.jpg

Domestic pigs

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.
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).
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 animal (see taboo food and drink).

Environmental impacts

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
Food and Agriculture Organization of the United Nations (FAO). 2006. FAOStat Website. [1]
Huffman, B. 2006. The Ultimate Ungulate Page Website [2]
Invasive Species Specialist Group (ISSG). 2006. "Global Invasive Species Database: Sus scrofa" [3]
Klober, Kelly. 1997 A Guide to Raising Pigs. Pownal, Vermont : Storey Publishing ISBN 1580170110
Moore, J.R. 2001. "Swine production: a global perspective" [4]
National Pork Board (NPB). 2006 The Daily Pork Website [5]
Nowak, R. M. and J. L. Paradiso. 1983. Walker's Mammals of the World. Baltimore, Maryland: The Johns Hopkins University Press. ISBN 0801825253
Oklahoma State University (OSU). 2006 Breeds of Livestock: Swine[6]
University of California Museum of Paleontology (UCMP) 2006. Ungulates: Hoofed Mammals
Voelker, W. 1986. The Natural History of Living Mammals. Medford, New Jersey: Plexus Publishing, Inc. ISBN 0937548081
Watson, Lydall. 2004 The Whole Hog. New York : Smithsonian Books ISBN 1588342166

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@@ Line 19: / Line 19: @@
 ''Sus philippensis'' Philippine warty pig<br>
 ''Sus salvanius'' Pygmy hog<br>
-''Sus scrofa'' Eurasian wild pig
+''Sus scrofa'' Eurasian wild boar
-:''Sus scrofa domestica'' Domestic pig
+:''Sus scrofa domesticus'' Domestic pig
 ''Sus verrucosus'' Javan warty pig
 {{Taxobox end}}
-'''Pigs''' are members of the genus ''Sus'', within the [[Suidae]] family. They are even-toed [[ungulate]]s, hoofed [[mammal]]s, native to [[Eurasia]]  and [[Africa]].  Pigs, in the wild, live mostly in forests and savannas and play an important role in nature.  The domestic pig, ''Sus scrofa domestica'', was one of the first animals domesticated by humans and is still today one of the most important domestic animals.
+'''Pigs''' are members of the genus ''Sus'', within the [[Suidae]] family. They are even-toed [[ungulate]]s, hoofed [[mammal]]s, native to [[Eurasia]]  and [[Africa]].  Pigs, in the wild, live mostly in forests and savannas 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.
 ==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 and many subspecies.  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) while the Eurasian wild boar, ''Suc scrofa'', 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).
+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. The Eurasian wild boar, ''Sus scrofa'', has the largest range of any wild ungulate (Watson 2002). There are 10 species of living pigs and many subspecies.  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) while 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 [[omnivore]]s, which means that they consume both plants and animals. They eat a wide variety of foods including acorns and other seeds, 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.
+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 [[omnivore]]s, 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.
 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 canines, called tusks, grow continually and become very sharp by the lowers and uppers rubbing against each other (Nowak 1983).
@@ Line 39: / Line 39: @@
 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.
-==Pig species==
+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:Bearded_Pig.JPG|thumb|right|300px|A Bearded Pig]]
-*''Sus barbatus'' [[Bearded Pig]]; Malaysia, Indonesia
-*''Sus bucculentus'' [[Vietnamese Warty Pig]]
-*''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.
-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.
 ==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]]. It was [[domesticated animal|domesticated]] approximately 5,000 to 7,000 years ago. Pigs are found across [[Europe]], the [[Middle East]] and extend into [[Asia]] as far as [[Indonesia]] and [[Japan]]. The distinction between wild and domestic animals is slight, and domestic pigs have become [[feral]] in many parts of the world (for example, [[New Zealand]]) and caused substantial environmental damage.
+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. It was [[domesticated animal|domesticated]] beginning about 10,000 years ago, possibally in both [[China]] and the [[Middle East]] (Clutton-Brock 1999).  Domestic pigs 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 (explorer)|De Soto]] and other early [[Spain|Spanish]] [[explorer]]s. Escaped pigs became [[feral]] and were freely used by [[Indigenous peoples of the Americas|Native Americans]] as food. The distinction between wild and domestic animals is slight, and domestic pigs have become feral in many parts of the world (for example, [[New Zealand]] and parts of [[North America]]) and have caused substantial environmental damage.
-''Sus scrofa'' has four subspecies, each occupying distinct geographical areas:
+The 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.
-*''Sus scrofa scrofa'' (western [[Africa]], Europe)
-*''Sus scrofa ussuricus'' (northern Asia and [[Japan]])
-*''Sus scrofa cristatus'' ([[Asia Minor]], [[India]])
-*''Sus scrofa vittatus'' (Indonesia)
-Pigs are one of the oldest forms of [[livestock]], having been domesticated as early as [[5th millennium B.C.E.|5000 B.C.E.]] [http://www.admin.ox.ac.uk/po/050311.shtml]. It is believed to have been domesticated either in the [[Near East]] or in [[China]] from the [[Wild Boar]]. The 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. Pigs were brought to southeastern [[North America]] from [[Europe]] by [[Hernando de Soto (explorer)|De Soto]] and other early [[Spain|Spanish]] [[explorer]]s. Escaped pigs became [[feral]] and were freely used by [[Indigenous peoples of the Americas|Native Americans]] as food.
 ===As food===
 The domestic pig is farmed for its meat 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 some [[religion]]s, such as [[Judaism]] and [[Islam]], there are [[religious restrictions on the consumption of pork]].
 In [[industrialization|industrialized]] nations, domestic pigs farming has shifted away from the [[Family farm hog pen|traditional pig farm]] to large-scale [[intensive pig farming|intensive pig farms]] where meat can be mass-produced. This has resulted in lower production costs, but more significant [[animal welfare]] concerns.
-[[Image:Porcs en llibertat.JPG|thumb|left|Pigs in an [[Extensive farming|extensive farm]]]]
 In [[developing nation]]s, and some parts of [[developed nation]]s, the domestic pig is frequently raised outdoors in yards. In some cases pigs are even raised in open fields where they are allowed to [[foraging|forage]]; they are watched by [[swineherd]]s, essentially [[shepherd]]s for pigs.
-In 2005, the global stocks of pigs showed China with 488.8 millino 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 wiht 26.9 million head, and Spai with 25.3 million head.
+In 2005, the global stock of pigs (about 1,000 million 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.
 [[Image:Hog confinement barn interior.jpg|frame|right|Intensively farmed pigs in batch pens]]
 ===As pets===
-Pigs are known to be [[intelligent]] animals and have been found to be more trainable than [[dog]]s or [[cat]]s.  Asian [[pot-bellied pig]]s, a smaller [[subspecies]] of the domestic pig, have made popular house [[pet]]s in the United States beginning in the latter half of the [[20th 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.
+Pigs are known to be [[intelligent]] animals and have been found to be more trainable than [[dog]]s or [[cat]]s.  Asian [[pot-bellied pig]]s, a smaller breed of the domestic pig, have made popular house [[pet]]s in the United States beginning in the latter half of the [[20th 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|right|Champion Berkshire boar at the 2005 [[Royal Adelaide Show]]]]
 Pigs are exhibited at [[agricultural show]]s, judged either as [[Stud (animal)|stud stock]] 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.
-==Linguistics==
 [[Image:Pigs.jpg|thumb|right|Domestic pigs]]
-===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===
-*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.
-* A young pig which has just weaned is called a ''shoat''
-* 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==
-{{main|Cultural references to pigs}}
-As an animal living closely with the people, pigs were and are frequently referenced in human culture.
 ==Pigs in religion==
@@ Line 122: / Line 72: @@
 ==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]
+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==
+:''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.''
-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.
 ==References==
+*Clutton-Brook, J. 1999. ''A Natural History of Domesticated Mammals''. Cambridge, UK : Cambridge University Press ISBN 0521634954
 *Food and Agriculture Organization of the United Nations (FAO). 2006. ''FAOStat'' Website. [http://faostat.fao.org/site/340/DesktopDefault.aspx?PageID=340]
 *Huffman, B. 2006. ''The Ultimate Ungulate Page'' Website [http://www.ultimateungulate.com]
@@ Line 140: / Line 90: @@
 *Watson, Lydall. 2004 ''The Whole Hog''.  New York : Smithsonian Books ISBN 1588342166
-==External links==
-{{Wikispecies|Sus}}
-{{Commons|Sus domesticus}}
-*[http://www.pork4kids.com/AskAFarmer.aspx National Pork Board's Children's Page]
-*[http://www.albertapork.com/Uploads/educational/pigbasics.pdf Alberta Pork informational page (PDF)]
-*[http://www.ansi.okstate.edu/breeds/swine/ Swine Breeds, with pictures]
-*[http://www.pigdiseases.com/ Managing pig health]
-*[http://www.thepigsite.com/diseaseinfo/ Information on over 130 pig diseases]
-*[http://www.thepigsite.com/diseaseinfo/problemsolver.php Pig Disease identification software tool]
-*[http://www.thepigsite.com/photos/ Lots of piggy photos]
 {{credit2|Pig|85850318|Domestic_pig|83111035}}
 [[Category:Life sciences]]