Pig

Taxobox
name = Pig

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image_width = 250px
image_caption = A sow and her piglet.
regnum = Animalia
phylum = Chordata
classis = Mammalia
subclassis = Theria
infraclassis = Eutheria
ordo = Artiodactyla
familia = Suidae
subfamilia = Suinae
genus = "Sus"
genus_authority = Linnaeus, 1758
subdivision_ranks = Species
subdivision = "Sus barbatus"
"Sus bucculentus"
"Sus cebifrons"
"Sus celebensis"
"Sus domestica"
†"Sus falconeri"
"Sus heureni"
†"Sus hysudricus"
"Sus oliveri"
"Sus philippensis"
"Sus scrofa"
†"Sus strozzi"
"Sus timoriensis"
"Sus verrucosus"

Pigs, also called hogs or swine, are ungulates which have been domesticated as sources of food, leather, and similar products since ancient times. More recently, they have been involved in biomedical research and treatments, especially for their eyes and hearts, which closely resemble those of humans. Their long association with humans has led to their considerable representation in cultural milieux from paintings to proverbs. There are 2 billion pigs on the planet. [ [http://www.fas.usda.gov/psdonline/psdQuery.aspx Production, Supply and Distribution Online Query] , United States Department of Agriculture, Foreign Agricultural Service] [ [http://www.fas.usda.gov/psdonline/psdReport.aspx?hidReportRetrievalName=Swine+Summary+Selected+Countries&hidReportRetrievalID=1649&hidReportRetrievalTemplateID=7 Swine Summary Selected Countries ] , United States Department of Agriculture, Foreign Agricultural Service, (total number is Production (Pig Crop) plus Total Beginning Stocks]

Native to Eurasia, they are collectively grouped under the genus "Sus" within the Suidae family. Despite pigs' reputation for gluttony, and another reputation for dirtiness, a lesser known quality is their intelligence. The nearest living relatives of the swine family are the peccariesVerify source|date=September 2008.

Description and behavior

A pig has a snout for a nose, small eyes, and a small tail, which may be curly, kinked, or straight. It has a thick body, short legs, and coarse hair. There are four toes on each foot, with the two large middle toes used for walking.

Pigs are omnivores, which means that they consume both plants and animals. Pigs will scavenge and have been known to eat any kind of food, including dead insects, worms, tree bark, rotting carcasses, garbage, and even other pigs. In the wild, they are foraging animals, primarily eating leaves, grasses, roots, fruits and flowers. Occasionally while in captivity, pigs may eat their own young if they become severely stressed.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.Fact|date=July 2008 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 are sharpened by the lowers and uppers rubbing against each other.

Pigs that are allowed to forage may be watched by swineherds. Because of their foraging abilities and excellent sense of smell, they are used to find truffles in many European countries. Domesticated pigs are commonly raised as livestock by farmers for meat (called pork), as well as for leather. Their bristly hairs are also used for brushes. Some breeds of pigs, such as the Asian pot-bellied pig, are kept as pets.

Breeding occurs throughout the year in the tropics, but births peak around rainy seasons. A female pig can become pregnant at around 8-18 months of age. She will then go into estrus every 21 days if not bred. Male pigs become sexually active at 8-10 months of age. [ The solitary adult males together and fight for the right to mate with a female. A single male usually wins control over 4 females on average. [http://animaldiversity.ummz.umich.edu/site/accounts/information/Sus_scrofa.html ADW: Sus scrofa: Information ] ] A litter of piglets typically contains between 6 and 12 piglets. After the young are weaned, two or more families may come together until the next mating season.

Pigs do not have functional sweat glands, [ [http://www.depts.ttu.edu/porkindustryinstitute/research/MANAGING%20HEAT%20STRESS%20IN%20OUTDOOR%20PIGS.htm Managing Heat Stress In Outdoor Pigs ] ] 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.

Species

* Bearded Pig ("Sus barbatus") [Müller, 1838]
* Indo-chinese (or Vietnam) Warty Pig ("Sus bucculentus"). [Heude, 1892]
* Visayan Warty Pig ("Sus cebifrons") [Heude, 1888]
* Celebes (or Sulawesi) Warty Pig ("Sus celebensis") [Müller & Schlegel, 1843]
* †"Sus falconeri"
* Flores Warty Pig ("Sus heureni") [Hardjasasmita, 1987]
* †"Sus hysudricus"
* Oliver's (or Mindoro) Warty Pig ("Sus oliveri") [Groves, 1997]
* Philippine Warty Pig ("Sus philippensis") [Nehring, 1886]
* Wild Boar ("Sus scrofa") [Linnaeus, 1758]
** Domestic Pig ("Sus scrofa domestica") [Linnaeus, 1758]
* †"Sus strozzi"
* Timor Warty Pig ("Sus timoriensis") [Müller & Schlegal, 1845]
* Javan Warty Pig ("Sus verrucosus") [Müller, 1840]

The Pygmy Hog is now in the monotypic genus "Porcula" again [Funk "et al." (2007)]

Domestic Pigs

Pigs have been domesticated since ancient times in the Old World and are known for their exceptional intelligence. Domestic Pigs are found across Europe, the Middle East and extend into Asia as far as Indonesia and Japan. They were brought to southeastern North America from Europe by De Soto and other early Spanish explorers. Pigs are particularly valued in China and on certain oceanic islands, where their self-sufficiency allows them to be turned loose, although the practice is not without its drawbacks (see below).

The Domestic Pig ("Sus scrofa domesticus") is usually given the scientific name "Sus scrofa", although some authors call it "S. domesticus", reserving "S. scrofa" for the Wild boar. It was domesticated approximately 5,000 to 7,000 years ago. Their coats are coarse and bristly. They are born brownish colored and tend to turn more grayish colored with age. The upper canines form sharp distinctive tusks that curve outward and upward. Compared to other artiodactyles, their head is relatively long, pointed, and free of warts. Their head and body length ranges from 900-1,800 mm and can weigh 50-350 kg.

Pigs can be trained to perform numerous simple tasks and tricks. Recently, they have enjoyed a measure of popularity as house pets, particularly the dwarf breeds.

Cultural references to pigs

Pigs are frequently referenced in culture and are a popular topic for idioms and famous quotes.

Pigs in religion

*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 Hinduism the god Vishnu took the form of a boar in order to save the earth from a demon who had dragged it to the bottom of the sea.
*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).
*In keeping with Leviticus 11:7, the dietary laws of Judaism (Kashrut, adj. Kosher) forbid, among other kinds of meat, the eating of pork in any form, considering the pig to be an unclean animal (see taboo food and drink).
*The eating of pork is also prohibited in Islam (see Halal), among Seventh-day Adventists and some other Christian denominations.
*In Catholicism, Eastern Orthodoxy and other older Christian groups, pigs are associated with Saint Anthony the Great, the patron saint of swineherds.

Environmental impacts

Domestic pigs that have escaped from farms or were allowed to forage in the wild, and in some cases wild boars which 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. Accidental or deliberate releases of pigs into countries or environments where they are an alien species have caused extensive environmental change. Their omnivorous diet, aggressive behaviour and their feeding method of rooting in the ground all combine to severely alter 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 ADW: Sus scrofa: Information ] ] The Invasive Species Specialist Group lists feral pigs on the list of the world's 100 worst invasive species and says: [ [http://www.issg.org/database/species/ecology.asp?si=73&fr=1&sts=sss Ecology of Sus scrofa] , Global Invasive Species Database, The Invasive Species Specialist Group]

Health issues

Pigs harbour a range of parasites and diseases that can be transmitted to humans. These include trichinosis, "Taenia solium", cysticercosis, and brucellosis. Pigs are also known to host large concentrations of parasitic ascarid worms in their digestive tract. [1] The presence of these diseases and parasites is one of the reasons why pork meat should always be well cooked or cured before eating. Some religious groups that consider pork unclean refer to these issues as support for their views. [2]

Pigs are susceptible to bronchitis and pneumonia. They have small lungs in relation to body size; for this reason, bronchitis or pneumonia can kill a pig quickly.

Pigs can be aggressive and pig-induced injuries are relatively common in areas where pigs are reared or where they form part of the wild or feral fauna. [3]

ee also

*Babirusa
*Boar
*Domestic pig
*Pot-bellied pig
*Fetal pig
*Hog-baiting
*Intensive pig farming
*List of pigs
*List of fictional pigs
*Pig Olympics
*Razorback
*Bacon
*Pork
*Ham
*Lard
*Hogzilla
*Unclean animals

Footnotes

References

* (2007). [http://dx.doi.org/10.1016/j.ympev.2007.08.007 The pygmy hog is a unique genus: 19th century taxonomists got it right first time round] . Molecular Phylogenetics and Evolution, Volume 45, Pages 427-436

External links

* [http://www.swinecast.com SwineCast podcast]
* [http://www.deh.gov.au/biodiversity/invasive/publications/pig/ Feral Pig Fact Sheet]
* [http://www.pigprogress.net/ Global Pig Production]
* [http://www.pbs.org/wnet/nature/pigs/index.html Nature: The Joy of Pigs - TV special on PBS]
* [http://www.pigsaspets.org/ Pigs as Pets]
* [http://www.pighealth.com/ Pig Health]
* [http://www.ncbi.nlm.nih.gov/projects/genome/guide/pig/ Pig Genome Resources]
* [http://www.biolsci.org/v3i3 Special issue on swine genome research]
* [http://www.ansi.okstate.edu/breeds/swine/ Swine Breeds, with pictures]
* [http://www.pii.ttu.edu/ University Pig Teaching and Research Program]
* [http://www.upprs.com/ United Pet Pig Registry]