Jump to content

Pig

Edit links
This is a good article. Click here for more information.
Page semi-protected
From Wikipedia, the free encyclopedia

This article is about the domestic farm animal. For other animals known as "swine", seeSuina.For other uses, seeSwine (disambiguation)andPig (disambiguation).

Pig
Domestic pigs
Domesticated
Scientific classificationEdit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Suidae
Genus: Sus
Species:
S. domesticus
Binomial name
Sus domesticus
Synonyms[1]

Thepig(Sus domesticus), also calledswine(pl.:swine) orhog,is anomnivorous,domesticated,even-toed, hoofed mammal.It is named thedomestic pigwhen distinguishing it from other members of the genusSus.It is considered asubspeciesofSus scrofa(thewild boaror Eurasian boar) by some authorities, but as a distinctspeciesby others. Pigs were domesticated in theNeolithic,both in East Asia and in the Near East. When domesticated pigs arrived in Europe, they extensively interbred with wild boar but retained their domesticated features.

Pigs are farmedprimarily for meat, calledpork.The animal's skin orhideis used forleather.China is the world's largest pork 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, often cured asbacon.Some are kept aspets.

Pigs have featuredin human culturesince Neolithic times, appearing in art and literature for children and adults, and celebrated in cities such asBolognafor their meat products.

Description

The pig has a large head, with a long snout strengthened by a special prenasal bone and a disk ofcartilageat the tip.[2]The snout is used to dig into the soil to find food and is an acute sense organ. Thedental formulaof adult pigs is3.1.4.33.1.4.3,giving a total of 44teeth.The rear teeth are adapted for crushing. In males, the canine teeth can formtusks,which grow continuously and are sharpened by grinding against each other.[2]There are fourhoofedtoes 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 sparselybristledhair on their skin, though there are somewoolly-coated breeds such as theMangalitsa.[4]Adult pigs generally weigh between 140 and 300 kg (310 and 660 lb), though some breeds can exceed this range. Exceptionally, a pig called Big Bill weighed 1,157 kg (2,551 lb) and had a shoulder height of 1.5 m (4 ft 11 in).[5]

Pigs possess bothapocrineandeccrine sweat glands,although the latter are limited to the snout.[6]Pigs, like other "hairless" mammals such as elephants, do not use thermal sweat glands in cooling.[7]Pigs are less able than many other mammals to dissipate heat from wetmucous membranesin the mouth by panting. Theirthermoneutralzone is 16–22 °C (61–72 °F).[8]At higher temperatures, pigs lose heat bywallowingin mud or water via evaporative cooling, although it has been suggested that wallowing may serve other functions, such as protection from sunburn,ecto-parasitecontrol, and scent-marking.[9]Pigs are among four mammalian species with mutations in thenicotinic acetylcholine receptorthat protect againstsnake venom.Mongooses,honey badgers,hedgehogs,and pigs all have different modifications to the receptor pocket which preventsα-neurotoxinfrom binding.[10]Pigs have small lungs for their body size, and are thus more susceptible than other domesticated animals to fatalbronchitisandpneumonia.[11]Thegenomeof the pig has been sequenced; it contains about 22,342protein-codinggenes.[12][13][14]

  • Skeleton
    Skeleton
  • Skull
    Skull
  • Bones of the foot
    Bones of the foot

Evolution

Phylogeny

Domestic pigs are related to other pig species as shown in thecladogram,based on phylogenetic analysis usingmitochondrial DNA.[15]

Suidae

Babirusa

Indonesia
Africa

Visayan warty pig

Philippine warty pig

Wild boar

Domestic pig

East Asian pigs

European pigs

Eurasia
Southeast Asia

Taxonomy

The pig is most often considered to be asubspeciesof thewild boar,which was given the nameSus scrofabyCarl Linnaeusin 1758; following from this, the formal name of the pig isSus scrofa domesticus.[16][17]However, in 1777,Johann Christian Polycarp Erxlebenclassified the pig as a separatespeciesfrom the wild boar. He gave it the nameSus domesticus,still used by some taxonomists.[18]TheAmerican Society of Mammalogistsconsiders it a separate species.[19]

Domestication in the Neolithic

Further information:Domestication
The initial emergence of wild pigs, followed by the genetic divergence between boars and pigs and the domestication of pigs[20]

Archaeological evidence shows that pigs weredomesticatedfrom wild boar in theNear Eastin or around theTigrisBasin,[21]being managed in a semi-wild state much as they are managed by some modern New Guineans.[22]There were pigs inCyprusmore 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 theBronze Age,as rural populations instead focused 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 extinctghost populationof wild pigs during thePleistocene.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 createddomestication islandsin 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]

DNAevidence 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]

History

Columbian Exchange

Among the animals that the Spanish introduced to theChiloé Archipelagoin the 16th centuryColumbian Exchange,pigs were the most successful in adapting to local conditions. The pigs benefited from abundantshellfishandalgaeexposed by the largetidesof the archipelago.[33]Pigs were brought to southeastern North America from Europe byde Sotoand other early Spanishexplorers.Escaped pigs becameferal.[34]

Feral pigs

Main article:Feral pig
A family of feral pigs

Pigs have escaped from farms and goneferalin many parts of the world. Feral pigs in the southeastern United States have migrated north to theMidwest,where many state agencies have programs to remove them.[35][36][37]Feral pigs in New Zealand and northernQueenslandhave caused substantial environmental damage.[38][39]Feral hybrids of the European wild boar with the domestic pig are disruptive to both environment and agriculture, as they destroy crops, spread animal diseases includingFoot-and-mouth disease,and consume wildlife such as juvenile seabirds and youngtortoises.[40]Feral pig damage is especially an issue in southeastern South America.[41][42]

Reproduction

Physiology

Reproductive systemof the boar
Reproductive system of the sow

Female pigs reach sexual maturity at 3–12 months of age and come intoestrusevery 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. The gestation period averages 112–120 days.[43]

Piglets keeping warm together

Estruslasts 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.Androstenolis one of the pheromones produced in the submaxillary salivary glands of boars that trigger the female's response.[44]The female cervix contains a series of five interdigitating pads, or folds, that hold the boar's corkscrew-shaped penis during copulation.[45]Females havebicornuate uterusesand twoconceptusesmust be present in both uterine horns to enable pregnancy to proceed.[46]The mother's body recognises that it is pregnant on days 11 to 12 of pregnancy, and is marked by thecorpus luteum's producing the sex hormoneprogesterone.[47]To sustain the pregnancy, the embryo signals to the corpus luteum with the hormonesestradiolandprostaglandin E2.[48]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.[49]During mid to late pregnancy, the corpus luteum relies primarily onluteinizing hormonefor maintenance until birth.[48]

Archeological evidence indicates that medieval European pigs farrowed, or bore a litter of piglets, once per year.[50]By the nineteenth century, European piglets routinely double-farrowed, or bore two litters of piglets per year. It is unclear when this shift occurred.[51]Pigs have amaximum life spanof about 27 years.[52]

Nest-building

A characteristic of pigs which they share with carnivores isnest-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.[53]

Nest-building occurs during the last 24 hours before the onset of farrowing, and becomes most intense 12 to 6 hours before farrowing.[54]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.[55]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.[54]

Nursing and suckling

Pigs have complex nursing and suckling behaviour.[56]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.[57]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.[58]

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.[59]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.[60]

  • Sows typically have 12–14 nipples.
    Sows typically have 12–14 nipples.
  • A sow with suckling piglets
    A sow with suckling piglets

Teat order

In pigs,dominancehierarchies 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 theanteriorteats, 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.[53]Stimulation of the anterior teats appears to be important in causing milk letdown,[61]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.[62]

Behaviour

Social

American Yorkshirepigs in a wallow

Pig behaviour is intermediate between that of otherartiodactylsand ofcarnivores.[53]Pigs seek out the company of other pigs and often huddle to maintain physical contact, but they do not naturally form large herds. They live in groups of about 8–10 adult sows, some young individuals, and some single males.[54]Pigs confined in a simplified, crowded, or uncomfortable environment may resort totail-biting;farmers sometimesdock the tailsof pigs to prevent the problem, or may enrich the environment with toys or other objects to reduce the risk.[63][64]

Temperature control

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.[9]They do not submerge completely under the mud, but vary the depth and duration of wallowing depending on environmental conditions.[9]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.[9]They may use mud as a sunscreen, or to keep parasites away.[9]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.[65]

Eating, feeding, sleeping

Pigs around a rotary feeder

Where pigs are allowed to roam freely, they walk roughly 4 km daily,scavengingwithin a home range of around a hectare. Farmers in Africa often choose such a low-input, free-range production system.[66]

If conditions permit, pigs feed continuously for many hours and then sleep for many hours, in contrast toruminants,which tend to feed for a short time and then sleep for a short time. Pigs areomnivorousand versatile in their feeding behaviour. They primarily eat leaves, stems, roots, fruits, and flowers.[67]

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 animalsweanedtoo early. Pigs root and dig into the ground to forage for food. Rooting is also a means of communication.[68]

Intelligence

A pig using a specifically designed joystick[69]

Pigs are relatively intelligent animals, roughly on par withdogs.They distinguish each other as individuals, spend time in play, and form structured communities. They have good long-term memory and they experience emotions, changing their behaviour in response to the emotional states of other pigs. In terms of experimental tasks, pigs can perform tasks that require them to identify the locations of objects; they can solve mazes; and they can work with a simple language of symbols. They displayself-recognition in a mirror.Pigs have been trained to associate different sorts of music (Bach and a military march) with food and social isolation respectively, and could communicate the resulting positive or negative emotion to untrained pigs.[70][71]Pigs can be trained to use ajoystickwith their snout to select a target on screen.[69]

Senses

Atrained pigusing its sensitive nose to assist the search for wildtrufflesin France

Pigs havepanoramicvision of approximately 310° andbinocular visionof 35° to 50°. It is thought they have noeye accommodation.[72]Other animals that have no accommodation, e.g. sheep, lift their heads to see distant objects.[73]The extent to which pigs have colour vision is still a source of some debate; however, the presence ofcone cellsin the retina with two distinct wavelength sensitivities (blue and green) suggests that at least some colour vision is present.[74]

Pigs have a well-developed sense of smell; this is exploited in Europe wheretrained pigsfind undergroundtruffles.[75]Pigs have 1,113 genes for smell receptors, compared to 1,094 in dogs; this may indicate an acute sense of smell, but against this, insects have only around 50 to 100 such genes but make extensive use of olfaction.[76]Olfactory rather than visual stimuli are used in the identification of other pigs.[77]Hearing is well developed; sounds are localised by moving the head. Pigs use auditory stimuli extensively for communication in all social activities.[78]Alarm or aversive stimuli are transmitted to other pigs not only by auditory cues but also bypheromones.[79]Similarly, recognition between the sow and her piglets is by olfactory and vocal cues.[80]

Pests and diseases

Trichinella spiralislarvae in uncooked pig meat

Pigs are subject to many pests and diseases which can seriously affect productivity and cause death. These includeparasitessuch asAscarisroundworms,virusdiseases such as thetick-borneAfrican Swine Fever,bacterial infections such asClostridium,arthritiscaused byMycoplasma,and stillbirths caused byParvovirus.[81]

Some parasites of pigs are apublic healthrisk as they can be transmitted to humans in undercooked pork. These are the pork tapewormTaenia 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.[82]

In agriculture

Further information:Pig farming § Terminology

Production

Main article:Pig farming

Pigs have been raised outdoors, and sometimes allowed toforagein woods or pastures. In industrialized nations, pig production has largely switched to large-scaleintensive pig farming.This has lowered production costs but has caused concern about possiblecruelty.As consumers have become concerned with the humane treatment of livestock, demand for pasture-raised pork in these nations has increased.[83]Most pigs in the US receiveractopamine,abeta-agonist drug,which promotes muscle instead of fat and quicker weight gain, requiring less feed to reach finishing weight, and producing lessmanure.China has requested that pork exports be ractopamine-free.[84]With a population of around 1 billion individuals, the domesticated pig is one of the most numerous large mammals on the planet.[85][86]

Like all animals, pigs are susceptible to adverse impacts fromclimate change,such asheat stressfrom increased annual temperatures and more intenseheatwaves.Heat stress has increased rapidly between 1981 and 2017 on pig farms in Europe. Installing aground-coupled heat exchangeris an effective intervention.[87]

  • Indoor pig farm, Sweden, 1911
    Indoor pig farm, Sweden, 1911
  • Sow in stall with separate piglet balcony to prevent crushing, Germany, 1959
    Sow in stall with separate piglet balcony to prevent crushing, Germany, 1959
  • Free range pigs with field shelters, England, 2006
    Free rangepigs with field shelters, England, 2006
  • FAOdata for 2021
  • Pork is tied with chicken as the most commonly consumed meat worldwide.
    Pork is tied with chicken as the most commonly consumed meat worldwide.
  • Pork production has grown substantially over the recent 60 years.
    Pork production has grown substantially over the recent 60 years.
  • Production of pork worldwide, by country in 2021.
    Production of pork worldwide, by country in 2021.

Breeds

Main article:List of pig breeds

Around 600breedsof pig have been created by farmers around the world, mainly in Europe and Asia, differing in coloration, shape, and size.[88]According toThe Livestock Conservancy,as of 2016, three breeds of pig are critically rare (having a global population of fewer than 2000). They are theChoctaw hog,theMulefoot,and theOssabaw Island hog.[89]The smallest known pig breed in the world is theGöttingen minipig,typically weighing about 26 kilograms (57 lb) as a healthy, full-grown adult.[90]

As pets

A mini pet pig

Vietnamese Pot-belliedpigs, aminiature breed of pig,have been kept as pets in the United States, beginning in the latter half of the 20th century.

Pigs are intelligent, social creatures. They are consideredhypoallergenicand are known to do quite well with people who have the usual animal allergies. Since these animals are known to have a life expectancy of 15 to 20 years, they require a long-term commitment.

Given pigs are bred primarily as livestock and have not been bred as companion animals for very long, selective breeding for a placid or biddable temperament is not well established. Pigs have radically differentpsychologyand behaviours compared to dogs, and exhibitfight-or-flightinstincts, an independent nature, and naturalassertiveness.[91]Male and female swine that have not been de-sexed may express unwanted aggressive behavior, and are prone to developing serious health issues.[92]Asrootingis found to be comforting, pigs kept in the house may root household objects, furniture or surfaces. Pet pigs should be let outside to allow them to fulfill their natural desire of rooting around.

Economy

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: UNFood and Agriculture Organization

Approximately 1.5 billion pigs are slaughtered each year for meat.[93]

The pork bellyfutures contractbecame an icon ofcommodities trading.It appears in depictions of the arena in popular entertainment, such as the 1983 filmTrading Places.[94]Trade in pork bellies declined, and they were delisted from theChicago Mercantile Exchangein 2011.[94][95]

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.[96]India, despite its large population, consumed under 0.3 million tonnes of pork in 2023.[97]International trade in pork (meat not consumed in the producing country) reached 13 million tonnes in 2020.[98]

Uses

Products

Pigs are farmedprimarily for meat, calledpork.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 includeham,bacon(mainly from the back and belly), andsausages.[99]Pork is further made intocharcuterieproducts such asterrines,galantines,pâtésandconfits.[100]Some sausages such assalamiare 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.[101]

The hide is made into pigskinleather,which is soft and durable; it can be brushed to formsuedeleather. These are used for products such asgloves,wallets,suede shoes, andleather jackets.[102]In the16th century,pig skin was the most popular book-binding material inGermany,thoughcalfskin was more common elsewhere.[103]

  • Pork chops
    Pork chops
  • Streaky or side bacon
    Streaky or sidebacon
  • Salami, a fermented and air-dried sausage, originally made in Italy
    Salami,a fermented and air-dried sausage, originally made in Italy
  • A 16th century book bound in pig skin
    A 16th century book bound in pig skin
  • A woman's suede gloves, England, c. 1820
    A woman's suede gloves, England, c. 1820

In medicine

The growth in publication of medical research papers using pigs and miniature pigs, and the research done on miniature pigs by organ system[104]

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.[105][106]

Pigs are good non-human candidates fororgan donationto humans, and in 2021 became the first animal to successfullydonate an organ to a humanbody.[107][108]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.[109]Pigs are good for human donation as the risk of cross-species disease transmission is reduced by the considerablephylogeneticdistance from humans.[110]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.[111]

Impact of pig husbandry

On public health

Further information:Zoonotic disease

Pig farms can serve as reservoirs of viral diseases that are dangerous to humans and so contribute to their outbreaks in human populations.[112]The2009 swine flu pandemicwas caused by aninfluenza Avariant which had first emerged in pigs.[113]Pigs were also essential to the first outbreak of theNipah virusin 1999, with 93% of the infected humans having had contact with pigs.[112]WhileJapanese encephalitisis primarily spread bymosquitoes,pigs are a known intermediary host.[114]There is also a potential for porcinecoronavirusessuch asporcine epidemic diarrhea virusorswine acute diarrhea syndrome coronavirusto spill over into human populations.[112]

On the environment

Main article:Environmental impact of pig farming
A typical waste lagoon in North Carolina

As with the other forms of meat, producing pork is more energy-intensive than plant-based foods, and it is associated with moregreenhouse gas emissionspercalorie.However, emissions from pork are many times smaller than those ofbeef,vealandmutton,though larger than ofchickenmeat.[115]

Intensive pig production is also associated withwater pollutionconcerns, as the swine waste is often stored above ground in so-called lagoons. These lagoons typically have high levels ofnitrogenandphosphorus,and can containtoxic heavy metalslikezincandcopper,microbialpathogens,or hold elevated concentrations of pharmaceuticals fromsubtherapeutic antibiotic use in swine.[116]This wastewater from lagoons is liable to reachgroundwateron farms, though there is little evidence for it reaching deeper into localdrinking watersupplies.[117]However, lagoon spills, such as from heavy rains in the wake of ahurricane,can lead to fish kills and algal blooms in local rivers.[116]In theUnited States,35,000 mi (56,000 km) of river across over 20 states were estimated to have been contaminated by manure leakage as of 2015.[118]There is also evidence that evaporation from lagoons can cause nitrogen and phosphorus to spread through the air as dry particles then reach other water basins when they fall out throughdry deposition.This process then also contributes to watereutrophication.[116]

On animal welfare

Further information:Cruelty to animals § Welfare concerns of farm animals,andIntensive pig farming
Sows ingestation crates,United States, 2010

Intensive pig production involves practices such ascastration,earmarking,tattooing for litter identification, taildocking,which are often done without the use ofanesthetic.[119][120]Painfulteeth clippingof piglets is also done to curtailcannibalism,behavioural instability and aggression, andtail biting,which are induced by the cramped environment.[121][122]In English indoor farming, young pigs (less than 110kg in weight) are allowed to be kept with less than one square meter of space per pig.[123]

Pigs often begin life in afarrowing or gestation crate,which is a small pen with a central cage, designed to allow the piglets to feed from their mother while preventing her from attacking or crushing them.[124]The crates are so small that the mother sows cannot turn around.[125][126]While wild piglets remain with their mothers for around 12 to 14 weeks, farmed piglets areweanedand removed from their mothers at between two and five weeks old.[127][128]Of the piglets born alive, 10% to 18% will not reach weaning age, instead succumbing to disease, starvation, dehydration, or accidental crushing by their mothers.[121][129]Unusually smallruntpiglets are typically killed immediately by staff through blunt trauma to the head.[130][131]Further, intensive farming involves sows giving birth to large litter sizes at an unnatural frequency, which increases the rate ofstillbornpiglets, and causes as many as 25%-50% of sows to die ofprolapse.[132][133]

In culture

Main article:Pigs in culture

Pigs, widespread in societies around the world sinceNeolithictimes, have been used for many purposes in art, literature, and other expressions of humanculture.In classical times, theRomansconsideredporkthe finest of meats, enjoyingsausages,and depicting them in their art.[134]Across Europe, pigs have been celebrated incarnivalssince theMiddle Ages,[135]becoming specially important inMedieval Germanyin cities such asNuremberg,[136]and inEarly ModernItaly in cities such asBologna.[137][138]Pigs, especially miniature breeds, are occasionally kept as pets.[139][140]

In literature, both for children[141]and adults, pig characters appear in allegories, comic stories, and serious novels.[135][142][143]In art, pigs have been represented in a wide range of media and styles from the earliest times in many cultures.[144]Pig names are used in idioms andanimal epithets,often derogatory, since pigs have long been linked with dirtiness and greed,[145][146]while places such asSwindonare named for their association with swine.[147]The eating of pork isforbidden in IslamandJudaism,[148][149]but pigs are sacred in some other religions.[150][151]

References

  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. ^ab"Sus scrofa (wild boar)".Animal Diversity Web.
  3. ^Lockhart, Kim."American Wild Game / Feral Pigs / Hogs / Pigs / Wild Boar".gunnersden.Archived fromthe originalon 23 August 2018.Retrieved15 August2012.
  4. ^"Royal visit delights at the Three Counties Show".Malvern Gazette.15 June 2007.
  5. ^Bradford, Alina; Dutfield, Scott (5 October 2018)."Pigs, Hogs & Boars: Facts About Swine".LiveScience.Retrieved4 March2024.
  6. ^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.
  7. ^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.PMID1778649.S2CID28234765.
  8. ^"Sweat like a pig?".Australian Broadcasting Corporation. 22 April 2008.
  9. ^abcdeBracke, 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.
  10. ^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.Bibcode:2015Txcn...99...68D.doi:10.1016/j.toxicon.2015.03.007.PMID25796346.
  11. ^"Pros and Cons of Potbellied Pigs".Archived fromthe originalon 17 March 2014.Retrieved25 November2017.
  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.PMC5411780.PMID27646534.
  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.PMC7448572.PMID32543654.
  14. ^Karlsson, Max; Sjöstedt, Evelina; Oksvold, Per; Sivertsson, Åsa; Huang, Jinrong; Álvez, María Bueno; et al. (25 January 2022)."Genome-wide annotation of protein-coding genes in pig".BMC Biology.20(1): 25.doi:10.1186/s12915-022-01229-y.PMC8788080.PMID35073880.
  15. ^Wu, Gui-Sheng; Pang, Jun-feng; Zhang, Ya-Ping (2006)."Molecular phylogeny and phylogeography of Suidae".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 fromthe original(PDF)on 8 April 2011.
  18. ^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.
  19. ^"Explore the Database".mammaldiversity.org.Retrieved21 August2021.
  20. ^Bosse, Mirte (26 December 2018). "A Genomics Perspective on Pig Domestication".Animal Domestication.IntechOpen.doi:10.5772/intechopen.82646.ISBN978-1-83880-174-8.
  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.PMC3603306.PMID23180578.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.S2CID85302206.
  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.PMC2752532.PMID19706455.
  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.S2CID225700922.
  25. ^abGiuffra, 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.PMC1461048.PMID10747069.
  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.Archived fromthe originalon 10 February 2022.Retrieved8 August2021.
  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.PMID26323058.S2CID205350534.
  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.PMC6717267.PMID31405970.
  31. ^BBC News, "Pig DNA reveals farming history"4 September 2007. The report concerns an article in the journalPNAS
  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.PMC1976408.PMID17855556.
  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.Archived20 December 2007 at theWayback Machine
  35. ^"Feral Hogs in Missouri".Missouri Department of Conservation. Archived fromthe originalon 8 March 2017.Retrieved7 March2017.
  36. ^"Feral Hog Hunting Regulations".agfc.Archived fromthe originalon 22 February 2017.Retrieved7 March2017.
  37. ^"Feral Hog Management".Georgia DNR – Wildlife Resources Division.Archived fromthe originalon 8 March 2017.Retrieved8 March2017.
  38. ^Yoon, Carol Kaesuk (2 December 1992)."Alien Species Threaten Hawaii's Environment".The New York Times.
  39. ^"Introduced Birds and Mammals in New Zealand and Their Effect on the Environment – NZETC".nzetc.org.
  40. ^"World's 100 most destructive species named".The Independent.21 November 2004.Retrieved7 March2017.
  41. ^Bauru; Marília (12 April 2013)."Autorização para abate do javaporco tranquiliza produtores em Assis, SP".Bauru e Marília.
  42. ^"IBAMA authorizes capture and slaughter of 'javaporcos' – Folha do Sul Gaúcho".Archived fromthe originalon 3 July 2017.
  43. ^"Feral Hog Reproductive Biology".16 May 2012. Archived fromthe originalon 22 November 2015.
  44. ^"G2312 Artificial Insemination in Swine: Breeding the Female".University of Missouri Extension. Archived fromthe originalon 8 March 2017.Retrieved7 March2017.
  45. ^"The Female – Swine Reproduction".livestocktrail.illinois.edu.Archived fromthe originalon 10 February 2022.Retrieved7 March2017.
  46. ^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.PMID3517318.
  47. ^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.PMC3436697.PMID22958877.
  48. ^abZiecik, A. J.; et al. (2018)."Regulation of the porcine corpus luteum during pregnancy".Reproduction.156(3): R57–R67.doi:10.1530/rep-17-0662.PMID29794023.
  49. ^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.PMID28628266.
  50. ^Ervynck, Anton; Dobney, Keith (2002)."A Pig for all Seasons? Approaches to the Assessment of Second Farrowing in Archaeological Pig Populations".Archaeofauna(11): 7–22.
  51. ^Bintliff, J.; Earle, T.; Peebles, C. (2008).A Companion to Archaeology.Wiley. p. 305.ISBN978-0-470-99860-1.
  52. ^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.PMC7286991.PMID32361879.
  53. ^abcClutton-Brock, Juliet (1987).A Natural History of Domesticated Mammals.Cambridge:Cambridge University Press.pp. 73–74.
  54. ^abcAlgers, 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.PMID17482189.S2CID9742677.
  55. ^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.
  56. ^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.
  57. ^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.PMID2005005.S2CID31788525.
  58. ^Algers, B (1993)."Nursing in pigs: communicating needs and distributing resources".Journal of Animal Science.71(10): 2826–2831.doi:10.2527/1993.71102826x.PMID8226386.
  59. ^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.
  60. ^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.PMID9632466.S2CID12493158.
  61. ^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.PMID4733757.
  62. ^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.
  63. ^"Tail docking and tail biting in pigs".Animal Husbandry Development Board.Retrieved4 March2024.
  64. ^"Pig Health- Tail Biting".National Animal Disease Information Service.Archived fromthe originalon 13 January 2013.Retrieved4 March2024.
  65. ^"Blowing Coat – Mini Pig Shedding FAQ".americanminipigassociation.2 April 2016.
  66. ^Thomas, Lian F; de Glanville, William A; Cook, Elizabeth A; Fèvre, Eric M (2013)."The spatial ecology of free-ranging domestic pigs (Sus scrofa) in western Kenya".BMC Veterinary Research.9(1): 46.doi:10.1186/1746-6148-9-46.ISSN1746-6148.PMC3637381.PMID23497587.
  67. ^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.S2CID84886946.
  68. ^"Rooting & Nudging Behaviors in Mini Pigs".americanminipigassociation.8 June 2016.
  69. ^abCroney, Candace C.; Boysen, Sarah T. (11 February 2021)."Acquisition of a Joystick-Operated Video Task by Pigs (Sus scrofa)".Frontiers in Psychology.12.doi:10.3389/fpsyg.2021.631755.PMC7928376.PMID33679560.
  70. ^Colvin, Christina M.; Marino, Lori."Signs of Intelligent Life".Natural History Magazine.Retrieved3 June2019.
  71. ^Angier, Natalie (9 November 2009)."Pigs Prove to Be Smart, if Not Vain".The New York Times.Retrieved28 July2010.
  72. ^"Animalbehaviour.net (Pigs)".Archived fromthe originalon 17 March 2012.Retrieved9 December2012.
  73. ^"Animalbehaviour.net (Sheep)".Archived fromthe originalon 26 December 2012.Retrieved9 December2012.
  74. ^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.
  75. ^Sullivan, Walter (24 March 1982)."Truffles: Why Pigs Can Sniff Them Out".The New York Times.
  76. ^McGlone, John J.; Archer, Courtney; Henderson, Madelyn (25 October 2022)."Interpretive review: Semiochemicals in domestic pigs and dogs".Frontiers in Veterinary Science.9.doi:10.3389/fvets.2022.967980.ISSN2297-1769.PMC9640746.PMID36387395.
  77. ^Houpt, Katherine A. (27 March 2018). "2. Aggression and Social Structure".Domestic Animal Behavior for Veterinarians and Animal Scientists.John Wiley & Sons.ISBN978-1-119-23276-6.
  78. ^Gonyou, H. W. (2001). "The Social Behaviour of Pigs". In Keeling, L. J.; Gonyou, H. W. (eds.).Social behaviour in farm animals.CABI Publishing. pp. 147–176.doi:10.1079/9780851993973.0000.ISBN978-0-85199-397-3.
  79. ^Vieuille-Thomas, C.; Signoret, J. P. (1992). "Pheromonal transmission of an aversive experience in domestic pigs".Journal of Chemical Ecology.18(9): 1551–1557.Bibcode:1992JCEco..18.1551V.doi:10.1007/bf00993228.PMID24254286.S2CID4386919.
  80. ^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.
  81. ^"Disease A-Z for Pigs".NADIS Animal Health Skills.Retrieved15 February2024.
  82. ^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.PMID9501363.
  83. ^Strom, Stephanie (2 January 2014)."Demand Grows for Hogs That Are Raised Humanely Outdoors".The New York Times.Retrieved15 April2015.
  84. ^Charles, Dan (14 August 2015)."A Muscle Drug For Pigs Comes Out Of The Shadows".NPR.
  85. ^"PSD Online".fas.usda.gov.
  86. ^Swine Summary Selected CountriesArchived29 March 2012 at theWayback Machine,United States Department of Agriculture, Foreign Agricultural Service, (total number is Production (Pig Crop) plus Total Beginning Stocks
  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.PMID30671619.S2CID58951606.
  88. ^Miao, Jian; Chen, Zitao; Zhang, Zhenyang; Wang, Zhen; Wang, Qishan; Zhang, Zhe; Pan, Yuchun (21 March 2023)."A web tool for the global identification of pig breeds".Genetics Selection Evolution.55(1): 18.doi:10.1186/s12711-023-00788-0.ISSN1297-9686.PMC10029154.PMID36944938.
  89. ^"The Livestock Conservancy".livestock Conservancy.Retrieved7 March2017.
  90. ^"Taking good care of Ellegaard Göttingen Minipigs®"(PDF).Ellegaard Göttingen Minipigs.Archived fromthe original(PDF)on 19 April 2016.Retrieved2 July2018.
  91. ^"Info/Resource - Pigs 4 Ever - Gifts, supplies and resources for Pot-Bellied Pigs".pigs4ever.Retrieved11 October2020.
  92. ^"Spay and Neuter – American Mini Pig Association".americanminipigassociation.18 September 2014.
  93. ^"FAOSTAT".fao.org.Retrieved25 October2019.
  94. ^abDavey, Monica (30 July 2011)."Trade in Pork Bellies Comes to an End, but the Lore Lives".The New York Times.
  95. ^Garner, Carley (13 January 2010)."A Crash Course in Commodities".FT Press.Archived fromthe originalon 21 October 2013.Retrieved6 December2011.
  96. ^"Global pork production in 2022 and 2023, by country".Statista.Retrieved15 February2024.
  97. ^"Consumption volume of pork in India from 2013 to 2023".Statista.Retrieved15 February2024.
  98. ^Ter Beek, Vincent (13 December 2023)."The remarkable dynamics of global pig meat trade".Pig Progress.Retrieved15 February2024.
  99. ^"Pork Cuts".National Pork Board.Retrieved15 February2024.
  100. ^Davidson, Alan(2014). "Charcuterie (with links to other chapters: Hams, Sausages, Terrines, Pâtés, Galantines, Crepinettes, Andouille and Andouillette, Blood Sausages, White Pudding, Tripe)". In Jaine, Tom (ed.).The Oxford Companion to Food(3rd ed.). Oxford:Oxford University Press.p. 161.ISBN978-0-19-967733-7.
  101. ^Davidson, Alan(2014). "Sausages of Italy". In Jaine, Tom (ed.).The Oxford Companion to Food(3rd ed.). Oxford:Oxford University Press.p. 719.ISBN978-0-19-967733-7.
  102. ^"Pig leather".Leather Dictionary.Retrieved15 February2024.
  103. ^"Cover to Cover: Exposing the Bookbinder's Ancient Craft".TheUniversity of Adelaide.Retrieved6 March2024.
  104. ^Gutierrez, Karina; Dicks, Naomi; Glanzner, Werner G.; Agellon, Luis B.; Bordignon, Vilceu (16 September 2015)."Efficacy of the porcine species in biomedical research".Frontiers in Genetics.6:293.doi:10.3389/fgene.2015.00293.PMC4584988.PMID26442109.
  105. ^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.Retrieved27 January2018.
  106. ^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.Sinclair Research Centre, Auxvasse, MO, USA; Veterinary Medical Diagnostic Laboratory, Columbia, Missouri. Archived fromthe original(PDF)on 27 January 2018.Retrieved27 January2018.
  107. ^"Successful pig-to-human kidney transplant a" transformative moment "".yahoo.20 October 2021.Retrieved2 November2021.
  108. ^Lapid, Nancy (20 October 2021)."U.S. surgeons successfully test pig kidney transplant in human patient".Reuters.Retrieved2 November2021.
  109. ^"Progress in Xenotransplantation Opens Door to New Supply of Critically Needed Organs".NYU Langone News.Retrieved2 November2021.
  110. ^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.PMC539416.PMID12612110.
  111. ^Taylor, L. (2007)Xenotransplantation.Emedicine
  112. ^abcMcLean, Rebecca; Graham, Simon P. (4 April 2022)."The pig as an amplifying host for new and emerging zoonotic viruses".One Health.14.doi:10.1016/j.onehlt.2022.100384.PMC8975596.PMID35392655.
  113. ^Mena, Ignacio; Nelson, Martha I.; Quezada-Monroy, Francisco; Dutta, Jayeeta; Cortes-Fernández, Refugio; Lara-Puente, J Horacio; et al. (28 June 2016)."Origins of the 2009 H1N1 influenza pandemic in swine in Mexico".eLife.5.doi:10.7554/eLife.16777.ISSN2050-084X.PMC4957980.PMID27350259.
  114. ^"Japanese encephalitis".World Health Organization.December 2015.Archivedfrom the original on 13 July 2017.Retrieved29 October2017.
  115. ^World Food and Agriculture – Statistical Yearbook 2023 (Report). FAO. 2023.doi:10.4060/cc8166en.ISBN978-92-5-138262-2.
  116. ^abcBurkholder, JoAnn; Libra, Bob; Weyer, Peter; Heathcote, Susan; Kolpin, Dana; Thorne, Peter S.; Wichman, Michael (14 November 2007)."Impacts of waste from concentrated animal feeding operations on water quality".Environmental Health Perspectives.115(2): 308–12.doi:10.1289/ehp.8839.PMC1817674.PMID17384784.
  117. ^Fridrich, Beata; Krčmar, Dejan; Dalmacija, Božo; Molnar, Jelena; Pešić, Vesna; Kragulj, Marijana; Varga, Nataša (19 January 2014). "Impact of wastewater from pig farm lagoons on the quality of local groundwater".Agricultural Water Management.135:40–53.Bibcode:2014AgWM..135...40F.doi:10.1016/j.agwat.2013.12.014.
  118. ^"Agriculture".epa.gov.19 March 2015.Retrieved23 April2017.
  119. ^Cutler, R; Holyoake, P (2007)."The Structure and Dynamics of the Pig Meat Industry, prepared for Department of Agriculture, Fisheries and Forestry"(PDF).agriculture.gov.au.
  120. ^"Video Gallery".aussiepigs.Archived fromthe originalon 2 June 2019.Retrieved2 June2019.
  121. ^ab"Industry Focus".australianpork.au.Australian Pork Limited.
  122. ^"The risks associated with tail biting in pigs and possible means to reduce the need for tail docking considering the different housing and husbandry systems - Scientific Opinion of the Panel on Animal Health and Welfare".EFSA Journal.5(12): 611. 2007.doi:10.2903/j.efsa.2007.611.
  123. ^"Key figures for pig accommodation in England – legislative requirements"(PDF).AHDB Pork.Archived fromthe original(PDF)on 3 June 2019.
  124. ^Cutler, R; Holyoake, P. (2007)."The Structure and Dynamics of the Pig Meat Industry, prepared for Department of Agriculture, Fisheries and Forestry"(PDF).
  125. ^"Opinion on Free Farrowing Systems"(PDF).Farm Animal Welfare Committee.Archived fromthe original(PDF)on 3 April 2019.
  126. ^"Farrowing Fact Sheet".Viva! - The Vegan Charity.6 January 2016. Archived fromthe originalon 1 October 2020.Retrieved3 June2019.
  127. ^"Pig welfare".Compassion in World Farming.Retrieved3 June2019.
  128. ^"Revisiting Weaning Age Trends, Dynamics".Nationalhogfarmer.15 October 2005.Retrieved28 July2017.
  129. ^"Pre-weaning mortality".pigprogress.net.Pig Progress. 13 July 2010.
  130. ^Model code of practice for the welfare of animals: Pigs, Primary Industries Report Series third edition.2008.
  131. ^"Best of British? The Pig Industry Exposed"(PDF).Animal Aid.
  132. ^"Fact Sheet – 'Reproductive Health'"(PDF).australianpork.au.Australian Pork Limited. 2012. Archived fromthe original(PDF)on 30 March 2019.Retrieved2 June2019.
  133. ^Greenaway, Twilight (1 October 2018)."'We've bred them to their limit': death rates surge for female pigs in the US ".The Guardian.Retrieved17 November2018.
  134. ^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.JSTOR507411.S2CID193116973.
  135. ^abKomins, 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.
  136. ^Newey, Adam (8 December 2014)."Nuremberg, Germany: celebrating the city's sausage".The Daily Telegraph.
  137. ^"Eventi: Pane e salame"(in Italian). Istituzione Biblioteche Bologna. August 2009.Retrieved31 December2019.
  138. ^Virbila, S. Irene (7 August 1988)."Fare of the Country; Mortadella: Bologna's Bologna".The New York Times.
  139. ^Porter, Valerie; Alderson, Lawrence; Hall, Stephen J.G.; Sponenberg, D. Phillip (2016). "Pig".Mason's World Encyclopedia of Livestock Breeds and Breeding(6 ed.). CABI. p. 616.ISBN978-1-7806-4794-4.
  140. ^The Joy of Pigs/ Pigs as Pets.PBS Nature. Accessed June 2017.
  141. ^Robinson, Robert D. (March 1968). "The Three Little Pigs: From Six Directions".Elementary English.45(3): 356–359.JSTOR41386323.
  142. ^Mullan, John(21 August 2010)."Ten of the best pigs in literature".The Guardian.
  143. ^Bragg, Melvyn."Topics - Pigs in literature".BBCRadio 4.Retrieved1 January2020.Animal Farm... Sir Gawain and the Green Knight... The Mabinogion... The Odyssey... (In Our Time)
  144. ^"Pig".Metropolitan Museum of Art.Retrieved2 January2020.
  145. ^"Fine Swine".The Daily Telegraph.2 February 2001.
  146. ^Horwitz, Richard P. (2002).Hog Ties: Pigs, Manure, and Mortality in American Culture.University of Minnesota Press. p. 23.ISBN0816641838.
  147. ^Mills, A. D. (1993).A Dictionary of English Place-Names.Oxford University Press. pp. 150, 318.ISBN0192831313.
  148. ^Qur'an2:173, 5:3, 6:145, and 16:115.
  149. ^Leviticus 11:3–8
  150. ^Dalal, Roshen (2011).Hinduism: An Alphabetical Guide.Penguin Books India. pp. 444–445.ISBN978-0-14-341421-6.
  151. ^Bonwick, James (1894)."Sacred Pigs".Library Ireland.
Wikimedia Commons has media related toSus domesticus.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Pig&oldid=1251741052"