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Pig farm in Finland
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Suidae
Genus: Sus
S. domesticus
Binomial name
Sus domesticus
Erxleben, 1777

The pig (Sus domesticus), often called swine (pl.: 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 scrofa (the wild boar or Eurasian boar) or a distinct species. Pigs were domesticated in the Neolithic, both in East Asia and in the Near East. When these arrived in Europe, they extensively interbred with wild boar but retained their domesticated features.

Pigs are farmed primarily for meat, called pork. The animal's skin or hide is used for leather. China is the world's largest pig producer, followed by the European Union and then the United States. Around 1.5 billion pigs are raised each year, producing some 120 million tonnes of meat.

Pigs have featured in human culture since Neolithic times, appearing in art and literature for children and adults.


The pig has a large head, with a long snout strengthened by a special prenasal bone and a disk of cartilage at the tip.[2] The snout is used to dig into the soil to find food and is an acute sense organ. The dental formula of adult pigs is, giving a total of 44 teeth. The rear teeth are adapted for crushing. In the male, the canine teeth can form tusks, which grow continuously and are sharpened by constantly being ground against each other.[2] There are four hoofed toes on each foot; the two larger central toes bear most of the weight, while the outer two are also used in soft ground.[3] Most pigs have rather sparsely bristled hair on their skin, though there are some woolly-coated breeds such as the Mangalitsa.[4]

Pigs possess both apocrine and eccrine sweat glands, although the latter are limited to the snout.[5] Pigs, like other "hairless" mammals such as elephants, do not use thermal sweat glands in cooling.[6] Pigs are less able than many other mammals to dissipate heat from wet mucous membranes in the mouth by panting. Their thermoneutral zone is 16–22 °C (61–72 °F).[7] At higher temperatures, pigs lose heat by wallowing in mud or water via evaporative cooling, although it has been suggested that wallowing may serve other functions, such as protection from sunburn, ecto-parasite control, and scent-marking.[8] Pigs are among four mammalian species with mutations in the nicotinic acetylcholine receptor that protect against snake venom. Mongooses, honey badgers, hedgehogs, and pigs all have different modifications to the receptor pocket which prevents α-neurotoxin from binding.[9] Pigs have small lungs for their body size, and are thus more susceptible than other domesticated animals to fatal bronchitis and pneumonia.[10] Pigs have a maximum life span of about 27 years.[11] The genome of the pig has been sequenced; it contains about 22,342 protein-coding genes.[12][13][14]



Domestic pigs are related to other pig species as shown in the cladogram, based on phylogenetic analysis using mitochondrial DNA.[15]




Red river hog



Visayan warty pig

Philippine warty pig

Bornean bearded pig

Javan warty pig

Sus scrofa

East Asian pigs

European pigs



The pig is most often considered to be a subspecies of the wild boar, which was given the name Sus scrofa by Carl Linnaeus in 1758; following from this, the formal name of the pig is Sus scrofa domesticus.[16][17] However, in 1777, Johann Christian Polycarp Erxleben classified the pig as a separate species from the wild boar. He gave it the name Sus domesticus, still used by some taxonomists.[18][19] The American Society of Mammalogists considers it a separate species.[20]

Domestication in the Neolithic

Neolithic pottery pig, Hemudu culture (7500 to 5300 years ago), Zhejiang, China

Archaeological evidence shows that pigs were domesticated from wild boar in the Near East in or around the Tigris Basin,[21] being managed in the wild in a way similar to the way they are managed by some modern New Guineans.[22] There were pigs in Cyprus more than 11,400 years ago, introduced from the mainland, implying domestication in the adjacent mainland by then.[23] Pigs were separately domesticated in China, starting some 8,000 years ago.[24][25][26] In the Near East, pig husbandry spread for the next few millennia. It reduced gradually during the Bronze Age, as rural populations focused instead on commodity-producing livestock, but it was sustained in cities.[27]

Domestication did not involve reproductive isolation with population bottlenecks. Western Asian pigs were introduced into Europe, where they crossed with wild boar. There appears to have been interbreeding with a now extinct ghost population of wild pigs during the Pleistocene. The genomes of domestic pigs show strong selection for genes affecting behavior and morphology. Human selection for domestic traits likely counteracted the homogenizing effect of gene flow from wild boars and created domestication islands in the genome.[28][29] Pigs arrived in Europe from the Near East at least 8,500 years ago. Over the next 3,000 years they interbred with European wild boar until their genome showed less than 5% Near Eastern ancestry, yet retained their domesticated features.[30]

DNA evidence from subfossil remains of teeth and jawbones of Neolithic pigs shows that the first domestic pigs in Europe were brought from the Near East. This stimulated the domestication of local European wild boar, resulting in a third domestication event with the Near Eastern genes dying out in European pig stock. More recently there have been complex exchanges, with European domesticated lines being exported, in turn, to the ancient Near East.[31][32] Historical records indicate that Asian pigs were again introduced into Europe during the 18th and early 19th centuries.[25]


Columbian Exchange

Among the animals that the Spanish introduced to the Chiloé Archipelago in the 16th century Columbian Exchange, pigs were the most successful in adapting to local conditions. The pigs benefited from abundant shellfish and algae exposed by the large tides of the archipelago.[33] Pigs were brought to southeastern North America from Europe by de Soto and other early Spanish explorers. Escaped pigs became feral, disrupting the lives of Native Americans.[34]

With a population of around 1 billion individuals, the domesticated pig is one of the most numerous large mammals on the planet.[35][36]

Feral pigs

Pigs have escaped from farms and gone feral in many parts of the world. Feral pigs in the southeastern United States have migrated north to the Midwest, where many state agencies have programs to remove them.[37][38][39] Feral pigs in New Zealand and northern Queensland have caused substantial environmental damage.[40][41] Feral hybrids of the European wild boar with the domestic pig are disruptive to both environment and agriculture,[42] especially in southeastern South America.[43][44][45][46][47]


Female pigs reach sexual maturity at 3–12 months of age and come into estrus every 18–24 days if they are not successfully bred. The variation in ovulation rate can be attributed to intrinsic factors such as age and genotype, as well as extrinsic factors like nutrition, environment, and the supplementation of exogenous hormones.[48] The gestation period averages 112–120 days.[49]

Piglets keeping warm together

Estrus lasts two to three days, and the female's displayed receptiveness to mate is known as standing heat. Standing heat is a reflexive response that is stimulated when the female is in contact with the saliva of a sexually mature boar. Androstenol is one of the pheromones produced in the submaxillary salivary glands of boars that trigger the female's response.[50] The female cervix contains a series of five interdigitating pads, or folds, that hold the boar's corkscrew-shaped penis during copulation.[51] Females have bicornuate uteruses and two conceptuses must be present in both uterine horns for pregnancy to be established.[52] Maternal recognition of pregnancy in pigs occurs on days 11 to 12 of pregnancy and is marked by progesterone production from a functioning corpus luteum.[53] To avoid luteolysis by PGF2α, rescuing of the corpus luteum must occur via embryonic signaling of estradiol 17β and PGE2.[54] This signaling acts on both the endometrium and luteal tissue to prevent the regression of the corpus luteum by activation of genes that are responsible for corpus luteum maintenance.[55] During mid to late pregnancy, the corpus luteum relies primarily on Luteinizing hormone for maintenance until birth.[54][56]

Archeological evidence indicates that medieval European pigs farrowed, or bore a litter of piglets, once per year.[57] By the nineteenth century, European piglets routinely double-farrowed, or bore two litters of piglets per year. It is unclear when this shift occurred.[58]


American Yorkshire pigs in a wallow

Pig behaviour is intermediate between that of other artiodactyls and of carnivores.[59] Pigs seek out the company of other pigs, and often huddle to maintain physical contact, but do not naturally form large herds. They live in groups of about 8–10 adult sows, some young individuals, and some single males.[60]

Because of their relative lack of sweat glands, pigs often control their body temperature using behavioural thermoregulation. Wallowing, coating the body with mud, is a common behaviour.[8] They do not submerge completely under the mud, but vary the depth and duration of wallowing depending on environmental conditions.[8] Adult pigs start wallowing once the ambient temperature is around 17–21 °C (63–70 °F). They cover themselves in mud from head to tail.[8] They may use mud as a sunscreen, or to keep parasites away.[8] Most bristled pigs "blow their coat", meaning that they shed most of the longer, coarser stiff hair once a year, usually in spring or early summer, to prepare for the warmer months ahead.[61]

If conditions permit, pigs feed continuously for many hours and then sleep for many hours, in contrast to ruminants, which tend to feed for a short time and then sleep for a short time. Pigs are omnivorous and versatile in their feeding behaviour. They primarily eat leaves, stems, roots, fruits, and flowers.[62] They are noticeably intelligent,[63] on a par with dogs.[64][65]


Rooting is an instinctual comforting behaviour in pigs characterized by nudging the snout into something. It first happens when piglets are born to obtain their mother's milk, and can become a habitual, obsessive behaviour, most prominent in animals weaned too early. Pigs root and dig into the ground to forage for food. Rooting is also a means of communication.[66]


A characteristic of pigs which they share with carnivores is nest-building. Sows root in the ground to create depressions the size of their body, and then build nest mounds, using twigs and leaves, softer in the middle, in which to give birth. When the mound reaches the desired height, she places large branches, up to 2 metres in length, on the surface. She enters the mound and roots around to create a depression within the gathered material. She then gives birth in a lying position, unlike other artiodactyls which usually stand while birthing.[59]

Nest-building occurs during the last 24 hours before the onset of farrowing, and becomes most intense 12 to 6 hours before farrowing.[60] The sow separates from the group and seeks a suitable nest site with well-drained soil and shelter from rain and wind. This provides the offspring with shelter, comfort, and thermoregulation. The nest provides protection against weather and predators, while keeping the piglets close to the sow and away from the rest of the herd. This ensures they do not get trampled on, and prevents other piglets from stealing milk from the sow.[67] The onset of nest-building is triggered by a rise in prolactin level, caused by a decrease in progesterone and an increase in prostaglandin; the gathering of nest material seems to be regulated more by external stimuli such as temperature.[60]

Nursing and suckling

Pigs have complex nursing and suckling behaviour.[68] Nursing occurs every 50–60 minutes, and the sow requires stimulation from piglets before milk let-down. Sensory inputs (vocalisation, odours from mammary and birth fluids, and hair patterns of the sow) are particularly important immediately post-birth to facilitate teat location by the piglets.[69] Initially, the piglets compete for position at the udder; then the piglets massage around their respective teats with their snouts, during which time the sow grunts at slow, regular intervals. Each series of grunts varies in frequency, tone and magnitude, indicating the stages of nursing to the piglets.[70]

The phase of competition for teats and of nosing the udder lasts for about a minute, ending when milk begins to flow. The piglets then hold the teats in their mouths and suck with slow mouth movements (one per second), and the rate of the sow's grunting increases for approximately 20 seconds. The grunt peak in the third phase of suckling does not coincide with milk ejection, but rather the release of oxytocin from the pituitary into the bloodstream.[71] Phase four coincides with the period of main milk flow (10–20 seconds) when the piglets suddenly withdraw slightly from the udder and start sucking with rapid mouth movements of about three per second. The sow grunts rapidly, lower in tone and often in quick runs of three or four, during this phase. Finally, the flow stops and so does the grunting of the sow. The piglets may dart from teat to teat and recommence suckling with slow movements, or nosing the udder. Piglets massage and suckle the sow's teats after milk flow ceases as a way of letting the sow know their nutritional status. This helps her to regulate the amount of milk released from that teat in future sucklings. The more intense the post-feed massaging of a teat, the more milk that teat later releases.[72]

Teat order

In pigs, dominance hierarchies are formed at an early age. Piglets are precocious, and attempt to suckle soon after being born. The piglets are born with sharp teeth and fight for the anterior teats, as these produce more milk. Once established, this teat order remains stable; each piglet tends to feed on a particular teat or group of teats.[59] Stimulation of the anterior teats appears to be important in causing milk letdown,[73] so it might be advantageous to the entire litter to have these teats occupied by healthy piglets. Piglets locate teats by sight and then by olfaction.[74]


A trained pig using its sensitive nose to assist the search for wild truffles in France

Pigs have panoramic vision of approximately 310° and binocular vision of 35° to 50°. It is thought they have no eye accommodation.[75] Other animals that have no accommodation, e.g. sheep, lift their heads to see distant objects.[76] The extent to which pigs have colour vision is still a source of some debate; however, the presence of cone cells in the retina with two distinct wavelength sensitivities (blue and green) suggests that at least some colour vision is present.[77]

Pigs have a well-developed sense of smell; use is made of this in Europe where trained pigs find underground truffles.[78] Olfactory rather than visual stimuli are used in the identification of other pigs.[79] Hearing is well developed; sounds are localised by moving the head. Pigs use auditory stimuli extensively for communication in all social activities.[80] Alarm or aversive stimuli are transmitted to other pigs not only by auditory cues but also by pheromones.[81] Similarly, recognition between the sow and her piglets is by olfactory and vocal cues.[82]

Pests and diseases

Trichinella spiralis larvae in uncooked pig meat

Pigs are subject to many pests and diseases which can seriously affect productivity and cause death. These include parasites such as Ascaris roundworms, virus diseases such as the tick-borne African Swine Fever, bacterial infections such as Clostridium, arthritis caused by Mycoplasma, and stillbirths caused by Parvovirus.[83]

Some parasites of pigs are a public health risk as they can be transmitted to humans in undercooked pork. These are the pork tapeworm Taenia solium; a protozoan, Toxoplasma gondii; and a nematode, Trichinella spiralis. Transmission can be prevented by thorough sanitation on the farm; by meat inspection and careful commercial processing; and by thorough cooking, or alternatively by sufficient freezing and curing.[84]

In agriculture


Pigs have been raised outdoors, and sometimes allowed to forage in woods or pastures. In industrialized nations, pig production has largely switched to large-scale intensive pig farming. This has lowered production costs but has caused concern about possible cruelty. As consumers have become concerned with the humane treatment of livestock, demand for pasture-raised pork in these nations has increased.[85] Most pigs in the US receive ractopamine, a beta-agonist drug, which promotes muscle instead of fat and quicker weight gain, requiring less feed to reach finishing weight, and producing less manure. China has requested that pork exports be ractopamine-free.[86]

Like all animals, pigs are susceptible to adverse impacts from climate change, such as heat stress from increased annual temperatures and more intense heatwaves. Heat stress has increased rapidly between 1981 and 2017 on pig farms in Europe. Installing a ground-coupled heat exchanger is an effective intervention.[87]


Many breeds of pig have been created by farmers around the world, differing in coloration, shape, and size. According to The Livestock Conservancy, as of 2016, three breeds of pig are critically rare (having a global population of fewer than 2000). They are the Choctaw hog, the Mulefoot, and the Ossabaw Island hog.[88] The smallest known pig breed in the world is the Göttingen minipig, typically weighing about 26 kilograms (57 lb) as a healthy, full-grown adult.[89]


Global pig stock
in 2019
Number in millions
1. China (Mainland)310.4 (36.5%)
2. European Union143.1 (16.83%)
3. United States78.7 (9.26%)
4. Brazil40.6 (4.77%)
5. Russia23.7 (2.79%)
6. Myanmar21.6 (2.54%)
7. Vietnam19.6 (2.31%)
8. Mexico18.4 (2.16%)
9. Canada14.1 (1.66%)
10. Philippines12.7 (1.49%)

World total850.3
Source: UN Food and Agriculture Organization

Approximately 1.5 billion pigs are slaughtered each year for meat.[90]

The pork belly futures contract became an icon of commodities trading. It appears in depictions of the arena in popular entertainment, such as the 1983 film Trading Places.[91] Trade in pork bellies declined, and they were delisted from the Chicago Mercantile Exchange in 2011.[91][92]

In 2023, China produced more pork than any other country, 55 million tonnes, followed by the European Union with 22.8 million tonnes and the United States with 12.5 million tonnes. Global production in 2023 was 120 million tonnes.[93] India, despite its large population, consumed under 0.3 million tonnes of pork in 2023.[94] International trade in pork (meat not consumed in the producing country) reached 13 million tonnes in 2020.[95]



Pigs are farmed primarily for meat, called pork. Pork is eaten in the form of pork chops, loin or rib roasts, shoulder joints, steaks, and loin (also called fillet). The many meat products made from pork include ham, bacon, and sausages.[96] Pork is further made into charcuterie products such as terrines, galantines, pâtés and confits.[97] Some sausages such as salami are fermented and air-dried, to be eaten raw. There are many types, the original Italian varieties including Genovese, Milanese, and Cacciatorino, with spicier kinds from the South of Italy including Calabrese, Napoletano, and Peperone.[98]

The hide is made into pigskin leather, which is soft and durable; it can be brushed to form suede leather. These are used for products such as gloves, wallets, suede shoes, and leather jackets.[99]

In medicine

Pigs, both as live animals and as a source of post-mortem tissues, are valuable animal models because of their biological, physiological, and anatomical similarities to human beings. For instance, human skin is very similar to the pigskin, therefore pigskin has been used in many preclinical studies.[100][101]

Pigs are good non-human candidates for organ donation to humans, and in 2021 became the first animal to successfully donate an organ to a human body.[102][103] The procedure used a donor pig genetically engineered not to have a specific carbohydrate that the human body considers a threat–Galactose-alpha-1,3-galactose.[104] Pigs are good for human donation as the risk of cross-species disease transmission is reduced by the considerable phylogenetic distance from humans.[105] They are readily available, and the danger of creating new human diseases is low as domesticated pigs have been in close contact with humans for thousands of years.[106]

In culture

Pigs, widespread in societies around the world since Neolithic times, have been used for many purposes in art, literature, and other expressions of human culture. In classical times, the Romans considered pork the finest of meats, enjoying sausages, and depicting them in their art.[107] Across Europe, pigs have been celebrated in carnivals since the Middle Ages,[108] becoming specially important in Medieval Germany in cities such as Nuremberg,[109] and in Early Modern Italy in cities such as Bologna.[110][111] Pigs, especially miniature breeds, are occasionally kept as pets.[112][113]

In literature, both for children[114] and adults, pig characters appear in allegories, comic stories, and serious novels.[108][115][116] In art, pigs have been represented in a wide range of media and styles from the earliest times in many cultures.[117] Pig names are used in idioms and animal epithets, often derogatory, since pigs have long been linked with dirtiness and greed,[118][119] while places such as Swindon are named for their association with swine.[120] The eating of pork is forbidden in Islam and Judaism,[121][122] but pigs are sacred in some other religions.[123][124]


  1. ^ Groves, Colin P. (1995). "On the nomenclature of domestic animals". Bulletin of Zoological Nomenclature. 52 (2): 137–141. doi:10.5962/bhl.part.6749. Biodiversity Heritage Library
  2. ^ a b "Sus scrofa (wild boar)". Animal Diversity Web.
  3. ^ Lockhart, Kim. "American Wild Game / Feral Pigs / Hogs / Pigs / Wild Boar". gunnersden.com. Archived from the original on 23 August 2018. Retrieved 15 August 2012.
  4. ^ "Royal visit delights at the Three Counties Show". Malvern Gazette. 15 June 2007.
  5. ^ Sumena, K. B.; Lucy, K. M.; Chungath, J.J.; Ashok, N.; Harshan, K. R. (2010). "Regional histology of the subcutaneous tissue and the sweat glands of large white Yorkshire pigs". Tamil Nadu Journal of Veterinary and Animal Sciences. 6 (3): 128–135.
  6. ^ Folk, G.E.; Semken, H.A. (1991). "The evolution of sweat glands". International Journal of Biometeorology. 35 (3): 180–186. Bibcode:1991IJBm...35..180F. doi:10.1007/bf01049065. PMID 1778649. S2CID 28234765.
  7. ^ "Sweat like a pig?". Australian Broadcasting Corporation. 22 April 2008.
  8. ^ a b c d e Bracke, M. B. M. (2011). "Review of wallowing in pigs: Description of the behaviour and its motivational basis". Applied Animal Behaviour Science. 132 (1): 1–13. doi:10.1016/j.applanim.2011.01.002.
  9. ^ Drabeck, D. H.; Dean, A. M.; Jansa, S.A. (1 June 2015). "Why the honey badger don't care: Convergent evolution of venom-targeted nicotinic acetylcholine receptors in mammals that survive venomous snake bites". Toxicon. 99: 68–72. doi:10.1016/j.toxicon.2015.03.007. PMID 25796346.
  10. ^ "Pros and Cons of Potbellied Pigs". Archived from the original on 17 March 2014. Retrieved 25 November 2017.
  11. ^ Hoffman, J.; Valencak, T. G. (2020). "A short life on the farm: aging and longevity in agricultural, large-bodied mammals". GeroScience. 42 (3): 909–922. doi:10.1007/s11357-020-00190-4. PMC 7286991. PMID 32361879.
  12. ^ Li, Mingzhou; Chen, Lei; Tian, Shilin; Lin, Yu; Tang, Qianzi; Zhou, Xuming; Li, Diyan; Yeung, Carol K. L.; Che, Tiandong; Jin, Long; Fu, Yuhua (1 May 2017). "Comprehensive variation discovery and recovery of missing sequence in the pig genome using multiple de novo assemblies". Genome Research. 27 (5): 865–874. doi:10.1101/gr.207456.116. PMC 5411780. PMID 27646534.
  13. ^ Warr, A.; Affara, N.; Aken, B.; Beiki, H.; Bickhart, D. M.; Billis, K.; et al. (2020). "An improved pig reference genome sequence to enable pig genetics and genomics research". GigaScience. 9 (6): giaa051. doi:10.1093/gigascience/giaa051. PMC 7448572. PMID 32543654.
  14. ^ Karlsson, Max; Sjöstedt, Evelina; Oksvold, Per; Sivertsson, Åsa; Huang, Jinrong; Álvez, María Bueno; Arif, Muhammad; Li, Xiangyu; Lin, Lin; Yu, Jiaying; Ma, Tao (25 January 2022). "Genome-wide annotation of protein-coding genes in pig". BMC Biology. 20 (1): 25. doi:10.1186/s12915-022-01229-y. PMC 8788080. PMID 35073880.
  15. ^ Wu, Gui-Sheng; Pang, Jun-feng; Zhang, Ya-Ping (2006). "Molecular phylogeny and phylogeography of Suidae" (PDF). Zoological Research. 27 (2): 197–201.
  16. ^ "Taxonomy Browser". ncbi.nlm.nih.gov.
  17. ^ Gentry, Anthea; Clutton-Brock, Juliet; Colin P. Groves (2004). "The naming of wild animal species and their domestic derivatives" (PDF). Journal of Archaeological Science. 31 (5): 645–651. Bibcode:2004JArSc..31..645G. doi:10.1016/j.jas.2003.10.006. Archived from the original (PDF) on 8 April 2011.
  18. ^ Corbet and Hill (1992), cited in Wilson, D. E.; Reeder, D. M., eds. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. ISBN 978-0-8018-8221-0. OCLC 62265494.
  19. ^ Gentry, Anthea; Clutton-Brock, Juliet; Groves, Colin P. (1996). "Proposed conservation of usage of 15 mammal specific names based on wild species which are antedated by or contemporary with those based on domestic animals". Bulletin of Zoological Nomenclature. 53: 28–37. doi:10.5962/bhl.part.14102.
  20. ^ "Explore the Database". www.mammaldiversity.org. Retrieved 21 August 2021.
  21. ^ Ottoni, C; Flink, LG.; Evin, A.; Geörg, C.; De Cupere, B.; Van Neer, W.; et al. (2013). "Pig Domestication and Human-Mediated Dispersal in Western Eurasia Revealed through Ancient DNA and Geometric Morphometrics". Molecular Biology and Evolution. 30 (4): 824–32. doi:10.1093/molbev/mss261. PMC 3603306. PMID 23180578. our data suggest a narrative that begins with the domestication of pigs in Southwest Asia, at Upper Tigris sites including Çayönü Tepesi (Ervynck et al. 2001) and possibly Upper Euphrates sites including Cafer Höyük (Helmer 2008) and Nevalı Çori (Peters et al. 2005)
  22. ^ Rosenberg, M.; Nesbitt, R.; Redding, R. W.; Peasnall, BL (1998). "Hallan Çemi, pig husbandry, and post-Pleistocene adaptations along the Taurus-Zagros Arc (Turkey)". Paléorient. 24 (1): 25–41. doi:10.3406/paleo.1998.4667. S2CID 85302206.
  23. ^ Vigne, J. D.; Zazzo, A.; Saliège, J.F.; Poplin, F.; Guilaine, J.; Simmons, A. (2009). "Pre-Neolithic wild boar management and introduction to Cyprus more than 11,400 years ago". Proceedings of the National Academy of Sciences of the United States of America. 106 (38): 16135–16138. Bibcode:2009PNAS..10616135V. doi:10.1073/pnas.0905015106. PMC 2752532. PMID 19706455.
  24. ^ Lander, Brian; Schneider, Mindi; Brunson, Katherine (2019). "A History of Pigs in China: From Curious Omnivores to Industrial Pork". Journal of Asian Studies. 79 (4): 865–889. doi:10.1017/S0021911820000054.
  25. ^ a b Giuffra, E.; Kijas, J. M.; Amarger, V.; Carlborg, O.; Jeon, J. T.; Andersson, L. (2000). "The origin of the domestic pig: independent domestication and subsequent introgression". Genetics. 154 (4): 1785–1791. doi:10.1093/genetics/154.4.1785. PMC 1461048. PMID 10747069.
  26. ^ Jean-Denis Vigne; Anne Tresset; Jean-Pierre Digard (3 July 2012). History of domestication (PDF) (Speech).
  27. ^ Price, Max (March 2020). "The Genesis of the Near Eastern Pig". American Society of Overseas Research. Retrieved 8 August 2021.
  28. ^ Frantz, L (2015). "Evidence of long-term gene flow and selection during domestication from analyses of Eurasian wild and domestic pig genomes". Nature Genetics. 47 (10): 1141–1148. doi:10.1038/ng.3394. PMID 26323058. S2CID 205350534.
  29. ^ Pennisi, E. (2015). "The taming of the pig took some wild turns". Science. doi:10.1126/science.aad1692.
  30. ^ Frantz, Laurent A. F.; Haile, James; Lin, Audrey T.; Scheu, Amelie; Geörg, Christina; Benecke, Norbert; et al. (2019). "Ancient pigs reveal a near-complete genomic turnover following their introduction to Europe". Proceedings of the National Academy of Sciences. 116 (35): 17231–17238. Bibcode:2019PNAS..11617231F. doi:10.1073/pnas.1901169116. PMC 6717267. PMID 31405970.
  31. ^ BBC News, "Pig DNA reveals farming history" 4 September 2007. The report concerns an article in the journal PNAS
  32. ^ Larson, G.; Albarella, U.; Dobney, K.; Rowley-Conwy, P.; Schibler, J.; Tresset, A.; et al. (2007). "Ancient DNA, pig domestication, and the spread of the Neolithic into Europe" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 104 (39): 15276–15281. Bibcode:2007PNAS..10415276L. doi:10.1073/pnas.0703411104. PMC 1976408. PMID 17855556.
  33. ^ Torrejón, Fernando; Cisternas, Marco; Araneda, Alberto (2004). "Efectos ambientales de la colonización española desde el río Maullín al archipiélago de Chiloé, sur de Chile" [Environmental effects of the spanish colonization from de Maullín river to the Chiloé archipelago, southern Chile]. Revista Chilena de Historia Natural (in Spanish). 77 (4): 661–677. doi:10.4067/s0716-078x2004000400009.
  34. ^ II.G.13. – Hogs. Archived 20 December 2007 at the Wayback Machine
  35. ^ "PSD Online". fas.usda.gov.
  36. ^ Swine Summary Selected Countries Archived 29 March 2012 at the Wayback Machine, United States Department of Agriculture, Foreign Agricultural Service, (total number is Production (Pig Crop) plus Total Beginning Stocks
  37. ^ "Feral Hogs in Missouri". Missouri Department of Conservation. Archived from the original on 8 March 2017. Retrieved 7 March 2017.
  38. ^ "Feral Hog Hunting Regulations". agfc.com. Archived from the original on 22 February 2017. Retrieved 7 March 2017.
  39. ^ "Feral Hog Management". Georgia DNR – Wildlife Resources Division. Archived from the original on 8 March 2017. Retrieved 8 March 2017.
  40. ^ Yoon, Carol Kaesuk (2 December 1992). "Alien Species Threaten Hawaii's Environment". The New York Times.
  41. ^ "Introduced Birds and Mammals in New Zealand and Their Effect on the Environment – NZETC". nzetc.org.
  42. ^ "World's 100 most destructive species named". The Independent. 21 November 2004. Archived from the original on 26 May 2022. Retrieved 7 March 2017.
  43. ^ Bauru; Marília (12 April 2013). "Autorização para abate do javaporco tranquiliza produtores em Assis, SP". Bauru e Marília.
  44. ^ "IBAMA authorizes capture and slaughter of 'javaporcos' – Folha do Sul Gaúcho". Archived from the original on 3 July 2017.
  45. ^ "Javaporco dá prejuízo e amedronta produtores rurais de Maracaí, SP". Archived from the original on 23 January 2019. Retrieved 26 April 2013.
  46. ^ MS Rural – farmers are authorized to make populational control of exotic species, such as the European boar Archived 12 October 2014 at the Wayback Machine (in Portuguese)
  47. ^ "Status and Distribution of wild boar in Rio Grande do Sul, Southern Brazil". 2009.
  48. ^ Hughes, Paul (1980). Reproduction in the Pig. Massachusetts: The Butterworth Group. ISBN 0408709464.
  49. ^ "Feral Hog Reproductive Biology". 16 May 2012.
  50. ^ "G2312 Artificial Insemination in Swine: Breeding the Female". University of Missouri Extension. Archived from the original on 8 March 2017. Retrieved 7 March 2017.
  51. ^ "The Female – Swine Reproduction". livestocktrail.illinois.edu. Retrieved 7 March 2017.
  52. ^ Bazer, F. W.; Vallet, J. L.; Roberts, R. M.; Sharp, D. D.; Thatcher, W. W. (1986). "Role of conceptus secretory products in establishment of pregnancy". J. Reprod. Fertil. 76 (2): 841–850. doi:10.1530/jrf.0.0760841. PMID 3517318.
  53. ^ Bazer, Fuller W.; Song, Gwonhwa; Kim, Jinyoung; Dunlap, Kathrin A.; Satterfield, Michael Carey; Johnson, Gregory A.; Burghardt, Robert C.; Wu, Guoyao (1 January 2012). "Uterine biology in pigs and sheep". Journal of Animal Science and Biotechnology. 3 (1): 23. doi:10.1186/2049-1891-3-23. PMC 3436697. PMID 22958877.
  54. ^ a b Ziecik, A. J.; et al. (2018). "Regulation of the porcine corpus luteum during pregnancy". Reproduction. 156 (3): R57–R67. doi:10.1530/rep-17-0662. PMID 29794023.
  55. ^ Waclawik, A.; et al. (2017). "Embryo‐maternal dialogue during pregnancy establishment and implantation in the pig". Molecular Reproduction and Development. 84 (9): 842–855. doi:10.1002/mrd.22835. PMID 28628266.
  56. ^ Farmer, Chantal (2015). The gestating and lactating sow. The Netherlands: Wageningen Academic Publishers. ISBN 9789086868032. OCLC 899008362.
  57. ^ Ervynck, A., & Dobney, K. (2002). A Pig all Seasons? Approaches to the Assessment of Second Farrowing in Archaeological Pig Populations. Archaeofauna, (11).
  58. ^ Bintliff, J.; Earle, T.; Peebles, C. (2008). A Companion to Archaeology. Wiley. p. 305. ISBN 978-0-470-99860-1.
  59. ^ a b c Clutton-Brock, Juliet (1987). A Natural History of Domesticated Mammals. Cambridge: Cambridge University Press. pp. 73–74.
  60. ^ a b c Algers, Bo; Uvnäs-Moberg, Kerstin (1 June 2007). "Maternal behavior in pigs". Hormones and Behavior. Reproductive Behavior in Farm and Laboratory Animals: 11th Annual Meeting of the Society for Behavioral Neuroendocrinology. 52 (1): 78–85. doi:10.1016/j.yhbeh.2007.03.022. PMID 17482189. S2CID 9742677.
  61. ^ "Blowing Coat – Mini Pig Shedding FAQ". americanminipigassociation.com. 2 April 2016.
  62. ^ Kongsted, A. G.; Horsted, K.; Hermansen, J. E. (2013). "Free-range pigs foraging on Jerusalem artichokes (Helianthus tuberosus L.) – Effect of feeding strategy on growth, feed conversion and animal behaviour". Acta Agriculturae Scandinavica, Section A. 63 (2): 76–83. doi:10.1080/09064702.2013.787116. S2CID 84886946.
  63. ^ "10 of the smartest animals on Earth". MNN – Mother Nature Network. Retrieved 8 March 2017.
  64. ^ "Signs of Intelligent Life | Natural History Magazine". naturalhistorymag.com. Retrieved 3 June 2019.
  65. ^ Angier, Natalie (9 November 2009). "Pigs Prove to Be Smart, if Not Vain". The New York Times. Retrieved 28 July 2010.
  66. ^ "Rooting & Nudging Behaviors in Mini Pigs". americanminipigassociation.com. 8 June 2016.
  67. ^ Wischner, D.; Kemper, N.; Krieter, J. (2009). "Nest-building behaviour in sows and consequences for pig husbandry". Livestock Science. 124 (1): 1–8. doi:10.1016/j.livsci.2009.01.015.
  68. ^ Fraser, D (1980). "A review of the behavioural mechanisms of milk ejection of the domestic pig". Applied Animal Ethology. 6 (3): 247–256. doi:10.1016/0304-3762(80)90026-7.
  69. ^ Rohde Parfet, K.A.; Gonyou, H.W. (1991). "Attraction of newborn piglets to auditory, visual, olfactory and tactile stimuli". Journal of Animal Science. 69 (1): 125–133. doi:10.2527/1991.691125x. PMID 2005005. S2CID 31788525.
  70. ^ Algers, B (1993). "Nursing in pigs: communicating needs and distributing resources". Journal of Animal Science. 71 (10): 2826–2831. doi:10.2527/1993.71102826x. PMID 8226386.
  71. ^ Castren, H.; Algers, B.; Jensen, P.; Saloniemi, H. (1989). "Suckling behaviour and milk consumption in newborn piglets as a response to sow grunting". Applied Animal Behaviour Science. 24 (3): 227–238. doi:10.1016/0168-1591(89)90069-5.
  72. ^ Jensen, P.; Gustafsson, G.; Augustsson, H. (1998). "Massaging after milk ejection in domestic pigs – an example of honest begging?". Animal Behaviour. 55 (4): 779–786. doi:10.1006/anbe.1997.0651. PMID 9632466. S2CID 12493158.
  73. ^ Fraser, D (1973). "The nursing and suckling behaviour in pigs. I. The importance of stimulation of the anterior teats". British Veterinary Journal. 129 (4): 324–336. doi:10.1016/s0007-1935(17)36434-5. PMID 4733757.
  74. ^ Jeppesen, L.E. (1982). "Teat-order in groups of piglets reared on an artificial sow. II. Maintenance of teat order with some evidence for the use of odour cues". Applied Animal Ethology. 8 (4): 347–355. doi:10.1016/0304-3762(82)90067-0.
  75. ^ "Animalbehaviour.net (Pigs)". Archived from the original on 17 March 2012. Retrieved 9 December 2012.
  76. ^ "Animalbehaviour.net (Sheep)". Archived from the original on 26 December 2012. Retrieved 9 December 2012.
  77. ^ Lomas, C.A.; Piggins, D.; Phillips, C.J.C. (1998). "Visual awareness". Applied Animal Behaviour Science. 57 (3–4): 247–257. doi:10.1016/s0168-1591(98)00100-2.
  78. ^ Sullivan, Walter (24 March 1982). "Truffles: Why Pigs Can Sniff Them Out". The New York Times.
  79. ^ Houpt, Katherine A. (27 March 2018). "2. Aggression and Social Structure". Domestic Animal Behavior for Veterinarians and Animal Scientists. John Wiley & Sons. ISBN 978-1-119-23276-6.
  80. ^ Gonyou, H. W. (2001). "The Social Behaviour of Pigs". In Keeling, L. J.; Gonyou, H. W. (eds.). Social behaviour in farm animals. CABI Publishing. doi:10.1079/9780851993973.0000. ISBN 978-0-85199-397-3.
  81. ^ Vieuille-Thomas, C.; Signoret, J. P. (1992). "Pheromonal transmission of an aversive experience in domestic pigs". Journal of Chemical Ecology. 18 (9): 1551–1557. doi:10.1007/bf00993228. PMID 24254286. S2CID 4386919.
  82. ^ Jensen, P.; Redbo, I. (1987). "Behaviour during nest leaving in free-ranging domestic pigs". Applied Animal Behaviour Science. 18 (3–4): 355–362. doi:10.1016/0168-1591(87)90229-2.
  83. ^ "Disease A-Z for Pigs". NADIS Animal Health Skills. Retrieved 15 February 2024.
  84. ^ Gamble, H. R. (1 August 1997). "Parasites associated with pork and pork products". Revue Scientifique et Technique de l'OIE. 16 (2): 496–506. doi:10.20506/rst.16.2.1032.
  85. ^ Strom, Stephanie (2 January 2014). "Demand Grows for Hogs That Are Raised Humanely Outdoors". The New York Times. Retrieved 15 April 2015.
  86. ^ Charles, Dan (14 August 2015). "A Muscle Drug For Pigs Comes Out Of The Shadows". NPR.
  87. ^ Mikovits, Christian; Zollitsch, Werner; Hörtenhuber, Stefan J.; Baumgartner, Johannes; Niebuhr, Knut; Piringer, Martin; et al. (22 January 2019). "Impacts of global warming on confined livestock systems for growing-fattening pigs: simulation of heat stress for 1981 to 2017 in Central Europe". International Journal of Biometeorology. 63 (2): 221–230. Bibcode:2019IJBm...63..221M. doi:10.1007/s00484-018-01655-0. PMID 30671619. S2CID 58951606.
  88. ^ "The Livestock Conservancy". livestock Conservancy. Retrieved 7 March 2017.
  89. ^ "Taking good care of Ellegaard Göttingen Minipigs®" (PDF). Ellegaard Göttingen Minipigs. Archived from the original (PDF) on 19 April 2016. Retrieved 2 July 2018.
  90. ^ "FAOSTAT". fao.org. Retrieved 25 October 2019.
  91. ^ a b Davey, Monica (30 July 2011). "Trade in Pork Bellies Comes to an End, but the Lore Lives". The New York Times.
  92. ^ Garner, Carley (13 January 2010). "A Crash Course in Commodities". FT Press. Archived from the original on 21 October 2013. Retrieved 6 December 2011.
  93. ^ "Global pork production in 2022 and 2023, by country". Statista. Retrieved 15 February 2024.
  94. ^ "Consumption volume of pork in India from 2013 to 2023". Statista. Retrieved 15 February 2024.
  95. ^ Ter Beek, Vincent (13 December 2023). "The remarkable dynamics of global pig meat trade". Pig Progress. Retrieved 15 February 2024.
  96. ^ "Pork Cuts". National Pork Board. Retrieved 15 February 2024.
  97. ^ Davidson, Alan (2014). "Charcuterie (with links to other chapters: Hams, Sausages, Terrines, Pâtés, Galantines, Crepinettes, Andouille and Andouillette, Blood Sausages, White Pudding, Tripe)". In Tom Jaine (ed.). The Oxford Companion to Food (3rd ed.). Oxford: Oxford University Press. p. 161. ISBN 978-0-19-967733-7.
  98. ^ Davidson, Alan (2014). "Sausages of Italy". In Tom Jaine (ed.). The Oxford Companion to Food (3rd ed.). Oxford: Oxford University Press. p. 719. ISBN 978-0-19-967733-7.
  99. ^ "Pig leather". Leather Dictionary. Retrieved 15 February 2024.
  100. ^ Herron, Alan J. (5 December 2009). "Pigs as Dermatologic Models of Human Skin Disease" (PDF). ivis.org. DVM Center for Comparative Medicine and Department of Pathology Baylor College of Medicine Houston, Texas. Retrieved 27 January 2018. pig skin has been shown to be the most similar to human skin. Pigskin is structurally similar to the human epidermal and dermal-epidermal thickness ratios. Pigs and humans have similar hair follicle and blood vessel patterns in the skin. Biochemically, pigs contain dermal collagen and elastic content that is more similar to humans than other laboratory animals. Finally, pigs have similar physical and molecular responses to various growth factors.
  101. ^ Liu, J.; Kim, L.; Madsen, T.; Bouchard, G. F. "Comparison of Human, Porcine and Rodent Wound Healing With New Miniature Swine Study Data" (PDF). sinclairresearch.com. Sinclair Research Centre, Auxvasse, MO, USA; Veterinary Medical Diagnostic Laboratory, Columbia, MO, USA. Archived from the original (PDF) on 27 January 2018. Retrieved 27 January 2018. Pig skin is anatomically, physiologically, biochemically and immunologically similar to human skin
  102. ^ "Successful pig-to-human kidney transplant a "transformative moment"". www.yahoo.com. 20 October 2021. Retrieved 2 November 2021.
  103. ^ Lapid, Nancy (20 October 2021). "U.S. surgeons successfully test pig kidney transplant in human patient". Reuters. Retrieved 2 November 2021.
  104. ^ "Progress in Xenotransplantation Opens Door to New Supply of Critically Needed Organs". NYU Langone News. Retrieved 2 November 2021.
  105. ^ Dooldeniya, M. D.; Warrens, A. N. (2003). "Xenotransplantation: Where are we today?". Journal of the Royal Society of Medicine. 96 (3): 111–117. doi:10.1177/014107680309600303. PMC 539416. PMID 12612110.
  106. ^ Taylor, L. (2007) Xenotransplantation. Emedicine.com
  107. ^ MacKinnon, Michael (2001). "High on the Hog: Linking Zooarchaeological, Literary, and Artistic Data for Pig Breeds in Roman Italy". American Journal of Archaeology. 105 (4): 649–673. doi:10.2307/507411. JSTOR 507411. S2CID 193116973.
  108. ^ a b Komins, Benton Jay (2001). "Western Culture and the Ambiguous Legacies of the Pig". CLCWeb: Comparative Literature and Culture. 3 (4). doi:10.7771/1481-4374.1137.
  109. ^ Newey, Adam (8 December 2014). "Nuremberg, Germany: celebrating the city's sausage". The Daily Telegraph.
  110. ^ "Eventi: Pane e salame" (in Italian). Istituzione Biblioteche Bologna. August 2009. Retrieved 31 December 2019.
  111. ^ Virbila, S. Irene (7 August 1988). "Fare of the Country; Mortadella: Bologna's Bologna". The New York Times.
  112. ^ Valerie Porter, Lawrence Alderson, Stephen J.G. Hall, D. Phillip Sponenberg (2016). Mason's World Encyclopedia of Livestock Breeds and Breeding (sixth edition). Wallingford: CABI. ISBN 9781780647944. page 616
  113. ^ The Joy of Pigs/ Pigs as Pets. PBS Nature. Accessed June 2017.
  114. ^ Robinson, Robert D. (March 1968). "The Three Little Pigs: From Six Directions". Elementary English. 45 (3): 356–359. JSTOR 41386323.
  115. ^ Mullan, John (21 August 2010). "Ten of the best pigs in literature". The Guardian.
  116. ^ Bragg, Melvyn. "Topics - Pigs in literature". BBC Radio 4. Retrieved 1 January 2020. Animal Farm ... Sir Gawain and the Green Knight ... The Mabinogion ... The Odyssey ... (In Our Time)
  117. ^ "Pig". Metropolitan Museum of Art. Retrieved 2 January 2020.
  118. ^ "Fine Swine". The Daily Telegraph. 2 February 2001.
  119. ^ Horwitz, Richard P. (2002). Hog Ties: Pigs, Manure, and Mortality in American Culture. University of Minnesota Press. p. 23. ISBN 0816641838.
  120. ^ Mills, A. D. (1993). A Dictionary of English Place-Names. Oxford University Press. pp. 150, 318. ISBN 0192831313.
  121. ^ Qur'an 2:173, 5:3, 6:145, and 16:115.
  122. ^ Leviticus 11:3–8
  123. ^ Dalal, Roshen (2011). Hinduism: An Alphabetical Guide. Penguin Books India. pp. 444–445. ISBN 978-0-14-341421-6.
  124. ^ Bonwick, James (1894). "Sacred Pigs". Library Ireland.

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