"Pig" is a term used synonymously with "hog" and "swine" for the one domesticated suid species, Sus scrofa domesticus. In livestock circles, a pig becomes a hog when it passes the weight threshold of 50 kilograms. The word "swine" transcends age and sex but to many has a pejorative ring. A "gilt" is any immature version of a sow, whereas a "barrow" is a young, castrated male that can never grow up to become a boar. After a piglet has been weaned, it becomes a "shoat." Most of these terms are not used by a general public whose only encounter with this animal is in the supermarket. The meat of this often maligned beast yields some of the world’s best-tasting flesh and provides good-quality protein in large amounts.

Domestication

All domesticated pigs originated from the wild boar (Sus scrofa) (Epstein 1984). Within that one wild species, more than 20 subspecies are known in different parts of its natural range, which has extended from the British Isles and Morocco in the West to Japan and New Guinea in the East. But where in this vast stretch of territory the first domestication occurred is still uncertain, although the earliest archaeological records (c. 7000–5000 B.C.) have been concentrated in the Middle East and eastern Mediterranean.

Indeed, the recovery of bones of domesticated pigs has been done at Jericho (Palestine), Jarmo (Iraq), Catal Huyuk (Turkey), and Argissa-Margula (Greece), as well as other sites. But bones older than any of those from these sites were uncovered in 1994 at Hallan Cemi in southeastern Turkey. There, in the foothills of the Taurus Mountains, the pig was apparently kept as early as 8000 B.C., making it the oldest known domesticated creature besides the dog. Moreover, pig keeping at this site was found to predate the cultivation of wheat or barley. Both findings contradict the long-held twin assertions that sheep and goats were the world’s earliest domesticated herd animals and that crop growing preceded the raising of herd animals.

An alternative view places the beginning of swine domestication in Southeast Asia. Carl O. Sauer (1952) suggested that the pig under human control diffused from there northward to China. However, Seung Og Kim (1994) has suggested that political elites in northern China established their authority by controlling intensive pig production as early as 4300 B.C. Certainly, archaeology and cultural hubris have combined to convince many Chinese that it was their ancestors who first domesticated the pig. The Chinese ideograph for "home" consists of a character for "swine" beneath another character for "roof" (Simoons 1991).

Certain innate traits of the wild boar make it plausible that multiple domestications have occurred at different times and places in the Old World. This inquisitive, opportunistic artiodactyl may, in part, have domesticated itself by choosing to freely come into association with humans. Garbage at settlement sites provided a regular food supply, and human presence offered protection from large carnivores. Reproduction in captivity could have been initiated when captured wild piglets were tamed. Human control would have been easily accomplished, for it has been observed that the striped piglets of the wild boar behave just like the unstriped piglets of the domesticated species. The next step, unconscious selection, began the long process of evolving regional distinctions in the animal’s conformation. However, the emergence of distinctive breeds, as we know them today, dates mostly from the late eighteenth and nineteenth centuries, when artificial selection was implemented on a large scale.

Religion probably lay behind the transformation of the pig from a semidomesticated status to one of greater mutual dependency with humans. In ancient Egypt, followers of Seth sacrificed pigs to that god. On the Iberian Peninsula, the granite sculptures called verracos, carved by Celts between the sixth century B.C. and the first century A.D., suggest that pigs might have had a religious role. In ancient Greek and Roman times, pigs were sacrificed to deities. In China, the Manchus believed that a sacrificial pig drove away bad spirits and assured good fortune. In all these groups, the incentive of supplying live animals for cultic purposes could easily have resulted in breeding pigs toward greater dependency on humans.

Advantages of the Pig

From a contemporary utilitarian perspective, the pig is one of the glories of animal domestication. It is prolific. After a gestation period of only 4 months, a sow gives birth to an average of 10 piglets, though litter size may, on occasion, be as large as 30. Growth is rapid. In a 6-month period, piglets of 1.2 kilograms can potentially increase in weight by 5,000 percent. This growth translates into a higher return for energy invested than for other domesticated animals. Another advantage is the omnivory of pigs, which permits a wide range of food options; items that are plentiful and cheap can dominate the intake. For example, surplus crops, such as sweet potatoes in New Guinea, coconuts in Polynesia, maize in the midwestern United States, and barley in Denmark, are frequently enhanced in value because they can be fed to swine. A major disadvantage of pigs is their low ability to digest fibrous plant matter, so that, unlike ruminants, they cannot do well on cellulose alone.

The Range Pig

For most of their domesticated history, swine were kept in one of two ways: free-ranging in forests or sedentary in settlements. In neither case did they compete with humans for food, although pigs have the capacity to eat and thrive on the same nutrients. For the range pig, both plant and animal matter, on and beneath the forest floor, was sought. In Western Europe, where domesticated swine have been known since before 4000 B.C., they ate acorns, chestnuts, beechnuts, hazelnuts, and wild fruits such as berries, apples, pears, and hawthorns. Their powerful mobile snouts and sharp teeth were able to dig mushrooms, tubers, roots, worms, and grubs from the ground. Eggs, snakes, young birds, mice, rabbits, and even fawns were consumed as opportunity arose.

The use of pannage (pasturing in a forest) to feed pigs was recorded from antiquity in Europe and still has not totally disappeared. An abundant iconography suggests the role that swine played in the development of European rural society. The pig is always pictured as an animal with a long flat neck, straight back, narrow snout, small erect ears, and long legs. Nimble and resourceful, it thrived on mast (nuts from the forest floor). In the early Middle Ages, mast rights were a greater source of income from the forest than the sale of wood. But pannage required peasants to enclose their fields with wooden palisades or hedges to prevent pigs from entering and destroying their crops. As concern for forest resources grew, the pannage season was fixed by seigneurial decree. The main feeding period came in the autumn, when nuts, a highly concentrated source of nutrition, fell in large numbers. In many places, it became traditional to begin mast feeding on the feast of Saint Michael (September 29) and to conclude it on the last day of November (Laurans 1976).

Mast feeding has now disappeared from Europe except in a few places. Its best-known survival is in Spain, where the oak woodland still seasonally supports black and red Iberian swine (Parsons 1962). Although by 1990 these rustic mast-feeding breeds made up only 4 percent of the Spanish pig population, the cured pork products derived from them have been prized as especially delectable. Thus, cured hams (jamon ibérico) from these swine are very expensive; most famous are those from Jabugo, a meat-packing village in the Sierra Morena north of Huelva.

On his second voyage, Christopher Columbus brought the first pigs to the New World (1493). From an original stock of eight, they multiplied on the Caribbean island of Hispaniola, and many later became feral. Rounded up as needed, pigs were put on board ships bound for Mexico, Panama, Colombia, and all the islands in between. Francisco Pizarro, who had worked with swine in his youth in Extremadura, brought live pigs to the Andean highlands from Panama in 1531. The long-legged, nimble suid was well suited to move along with the expedition parties as a mobile fresh meat supply. Tropical America afforded no acorns or chestnuts, but an abundance of wild fruit, especially from palms, provided nourishment for the pigs. In semiarid zones, seed pods of leguminous trees were the common food of foraging swine.

The first pigs in what is now the United States arrived from Cuba with Hernando de Soto’s expedition (1539–42) through the Southeast. Later introductions came from the British Isles, most notably to John Smith’s settlement of Jamestown in 1607. A few years later, they had multiplied to several hundred head. In Virginia, and elsewhere in eastern North America, pigs fit well into the forested countryside as foragers. Abundant oak and chestnut mast in the Appalachians offered a good return in meat for almost no investment in feed or care. In late autumn, the semiferal animals were rounded up and slaughtered, and their fatty flesh was made into salt pork, which along with Indian corn was a staple of the early American diet. In the early nineteenth century, these Appalachian pigs were commercialized. The leading national and world position of Cincinnati, Ohio (often jokingly called "Porkopolis"), as a soap manufacturing center owes its origin to pigs brought there on barges for slaughter; their flesh was salted and their fat rendered into soap.

This type of hardy porker and wily beast of folk legend still survives in the Ozarks and elsewhere in the southern United States. In fact, these "razorbacks" could be descendants of those that accompanied the de Soto expedition. The explorer gave gifts of live pigs to the Indians, and when he died in 1542 near what is now Fort Smith, Arkansas, 700 pigs were counted among his property. In addition, Ossabow Island, off the coast of Georgia, still harbors a breed of swine considered to be direct descendants of those brought by the Spaniards.

In addition to the Caribbean Islands, other uninhabited islands around the world became homes of the pig. In many cases, the animals were introduced by explorers and mariners and left to reproduce on their own. Sailors on passing ships often rounded up and slaughtered some of these feral pigs to replenish shipboard larders. Nonetheless, pigs on islands often multiplied to the point where they destroyed native fauna and flora.

In Melanesia, semidomesticated pigs still forage in the forest and are slaughtered primarily for ritual purposes (Baldwin 1983). R. A. Rappaport (1967) has explained the impressive pig feasts among the Tsembaga people of New Guinea as a societal mechanism that fulfills the need to control the size, composition, and rate of growth of the pig population. Without the periodic slaughtering of large numbers, the pigs would seriously damage gardens and crops. Rappaport’s effort to understand pigs and ritual as part of a homeostatic balance became one of the landmark works of the developing subfield of cultural ecology. Whether such a pig complex makes economic sense has been debated because, in this case, the animal is not a regular source of human food. But aside from their meat, pigs must be appreciated in manifold ways: as a hedge against uncertainty (e.g., crop failure); as a negotiable store of surplus; as a source of fertilizer; and as disposers of garbage and other wastes.

The Garbage Pig

The garbage pig was essentially "presented" with its food intake, either at a fixed site or within a circumscribed area. In eastern Asia, where centuries-old deforestation and high population densities did not favor mast feeding, pig raising was long ago oriented toward consuming wastes. Important in China and Korea, at one time, was the privy pig, kept to process human excrement into flesh for human consumption. Four young pigs could derive sustenance from the waste of a family of four humans, which provided the animals with approximately 2 kilograms of human excreta and 220 grams of garbage each day (Miller 1990). In Asia, food provided by humans rather than by foraging promoted sedentary habits that, in turn, led to the evolution of several breeds with a swayback and a dishlike face. But even the miniaturized types of Asian pigs have big appetites and large litters.

The garbage pig could also be found in ancient civilizations outside of eastern Asia. Robert L. Miller (l990) has brilliantly reconstructed the scavenging role of the pig in dynastic Egypt. But, thus far, similar evidence is lacking for ancient Greece and Rome. In Europe, the garbage pig goes back to the Middle Ages but seems not to have been common until the fifteenth century, when the so-called Celtic pig, with white skin and pendant ears, emerged. Families fattened their pigs primarily on food scraps, and when winter neared, the animals were butchered. Their meat was cured and their fat rendered to make lard for cooking and especially for food preservation. Thus, the human diet was diversified during the cold months.

This form of pig keeping expanded as forest clearing advanced and the scale of food processing increased. Grist and oil mills generated large quantities of waste materials that could be consumed by pigs, as could the garbage from institutions like hospitals and convents. Before proper sewage disposal was implemented, many cities had swine populations to serve as ambulatory sanitation services. In medieval Paris, so many pigs were locally available for slaughter that pork was the cheapest meat. The monks of Saint Anthony – the patron saint of swineherds – were given special rights to keep pigs within the city walls. In New York City, pigs wandered the alleyways well into the nineteenth century. Naples was the last large European city to use pigs for sanitation. Neapolitan families each had a pig tethered near their dwellings to consume garbage and excrement.

Certain peasant societies still value the garbage pig as an element of domestic economy. In much of rural Latin America, pigs consume what they can find, to be later slaughtered with minimal investment in feed (Gade 1987). Lard has been an important product of pig keeping there. Frying was a cooking innovation introduced with the European conquest, and native people learned to depend on this source of animal fat. Today, however, the meat quality of these haphazardly fed animals no longer meets the health requirements of city dwellers, most of whom get their pork products through inspected channels.

Unlike sheep, whose wool may be more valuable than their flesh, or cattle that are kept for their milk or for use as draft animals, pigs have had no primary nonmeat uses. A possible minor exception has been the truffle pig, employed in France – mainly in the Périgord region – to locate the black truffles synonymous with gourmandise. A trained sow can detect from 6 meters away the smell of the unseen truffles.

Swine Distribution

World hog distribution is strongly affected by cultural and ecological factors. More than 40 percent of the world porcine inventory is in China, where density is among the highest anywhere: For every three people in China, there is one pig. Some of this swinish appeal is cultural preference, though much can be explained by lack of alternatives. Human population pressure in China does not permit the extravagance of devoting large areas of land to grazing herbivores. Swine in China long had a niche as scavengers, scatovores, and consumers of surplus food crops.

Europe, including Russia, has about 170 million pigs, and Denmark is the only country in the world that has more pigs than people. The United States and Canada together have about 70 million of the animals, which means roughly one pig for every four people. Brazil has about 32 million head. Pigs are more important on many Pacific Islands than their total number (less than 5 million) would suggest.

The Middle East, however, is one part of the world that is largely devoid of pigs. Those that are kept generally belong to non-Muslims (such as the Coptic Christian peasants in Egypt), but some marginalized Muslims may keep pigs secretly. In humid Southeast Asia, the Islamic injunction against pigs is somewhat more nuanced, and in Indonesia, Muslims are among those who consume the products of the more than 8 million swine in that country.

In India, where the Hindu majority views all flesh foods as unacceptable elements of the diet, there are only about 10 million pigs, and in non-Islamic Africa, pigs number only around 18 million, considerably less than one might expect. But there African swine fever has periodically wiped out pig populations.

Elsewhere, the Arctic and Subarctic have historically had few pigs for quite different reasons. Very short growing seasons do not provide sufficient feed to maintain them; moreover, piglets cannot survive extremely cold winters without proper protection. Thus, in Greenland, the Norse settlements between A.D. 986 and 1400 had cattle but no pigs.

Pork

Many think that pork is the most savory of all flesh foods. The abundance and quality of fat keeps the meat from tasting dry and imparts a characteristically rich flavor. High pork consumption patterns are found in both China and Europe. In China, it is more important than all other meats combined, and use is made of all parts of the pig, including its liver, kidneys, feet, knuckles, tongue, skin, tail, and blood (Anderson 1988; Simoons 1991). Most pork cuts are also fried in lard.

In Europe, more than in China, cured pork products are favored. Germans and Slavs enjoy a range of sausages such as pork brain sausage (Gehirnwurst), much appreciated in Germany but unavailable commercially in the United States. In addition, Russians and Poles are especially fond of suckling pig.

Spaniards also enjoy high pork consumption and have a special fondness for cured hams and suckling pigs. Cochonillo asado, a strongly traditional Castilian meal, features a 1-month-old piglet fed only on its mother’s milk and roasted in an earthenware dish. Spanish enthusiasm for pig meat stems in part from pork’s past importance as a symbol of cultural identity. Because Moors and Jews did not eat it, Christians saw the meat as more than simple nutrition. In sixteenth-century Spain, pork eating was an acid test faced by Spanish Moriscos and Marranos who publicly claimed conversion to Christianity. Conspicuous pork avoidance could result in an appearance before the tribunals of the Inquisition.

In North America, pork lost its preeminent position to beef in the early twentieth century. Aside from the fact that cattle ranchers were much better organized to promote their product, pork had acquired negative connotations as the main food in the monotonous diet of poor people and pioneers. At one time, pork also had unhealthy associations because of the potential for human infection by the organism Trichinella spiralis, carried by pigs, but federal meat inspection to certify trichina-free meat has greatly reduced the incidence of trichinosis. Still, wide knowledge of that old health risk continues to motivate cooks to make sure that pork is served only when fully cooked. Pork is considered done when it reaches an average interior temperature of 75.9° C (170° F).

Spareribs are often used in southern-style barbecue, and bacon, which comes from what the meat trade calls "pork bellies," continues as an important component of the traditional American breakfast. "Chitterlings," made from intestines, are eaten as part of the ethnic cuisine known as "soul food," but they appear in few other cases. In contrast, ham, mostly cured, has wide appeal. Virginia hams, especially those from Smithfield, have had the best reputation among connoisseurs. Fattened on peanuts and corn, Virginia porkers yield a ham that is smoked and then matured for a year.

Avoidance of Pig Meat

Despite the popularity of pork in much of the world, it can also be observed that no other domestic animal has provoked such negative reactions in so many as the pig. In Western countries, swine are commonly seen as a metaphor for filthy, greedy, smelly, lazy, stubborn, and mean. Yet these presumed attributes have not prevented pork consumption. In other cultures, however, strongly negative attitudes toward the pig have historically resulted in its rejection as human food and even, in some cases, as an animal fit to look at.

About one-fifth of the world’s population refrains from eating pork as a matter of principle. Muslims, 800 million strong, form the largest block of pork rejecters because the pig is specifically named in the Koran as an object of defilement. A millennium earlier, Jews had also decided that the pig was unacceptable as a source of food. In the Bible (Leviticus), the animal is rejected because it does not meet the arcane requirements of both having a split hoof (which it has) and chewing the cud (which it does not). It is quite possible that the prophet Mohammed acquired his conception of the pig as an unclean animal from the Jewish tradition.

The Jews, in turn, may have gotten their basic and negative idea about the pig from other neighboring peoples (Simoons 1994). Brian Hesse (1990), investigating Iron Age Palestine, found no evidence for a significant cultic role for pigs, which raises the intriguing question of whether Hebrew rules prohibited a food that no one ate in the first place. Although the Hittites of Anatolia kept pigs, they entertained negative notions about them. In dynastic Egypt, swineherds were a caste apart; pigs acquired a reputation for being unclean, and their flesh was not eaten by priests. Marvin Harris (1985) has asserted that because the pig does not fit into the hot and dry conditions of the Middle East, the Israelites banned it as an ecological misfit. Others, however, believe that the history of this fascinating taboo is more complicated than that (Simoons 1994).

Within the Christian tradition, adherents of the Ethiopian Orthodox Church do not consume pork, yet their religiously affiliated Coptic brothers in Egypt do eat it. Many Buddhists and the great majority of Hindus refuse pig meat, although in both cases this avoidance arises more from vegetarian conviction than from any explicit religious taboo toward the animal. The Mongols, those nomadic folk of central Asia whose way of life is ill suited to pig keeping, consider the pig to be a symbol of Chinese culture.

Historic reluctance to keep pigs and consume pork has also been noted in Scotland. Eric B. Ross (1983) has explained the rise of the Scottish aversion to the pig as a response to the ecological cost of keeping pigs after the decline of oak and beech forests. Because sheep raising best suited the subsequent moorland landscape, mutton became a cheaper and socially more acceptable source of animal protein.

Porcine Trends

In most industrialized countries since the 1960s, pig keeping has moved rapidly toward maximizing efficiency of production (Pond 1983). Animals are injected with growth hormones and spend their short lives within buildings in near darkness. Artificially inseminated sows (a technology that appeared in 1932) farrow in narrow steel cages. Piglets are removed early from their mother so that lactation ceases and her sexual receptivity is reactivated. In four months, another litter is produced. Piglets have their incisors removed, tails docked, ears notched, and in the case of males, their testes excised. Most pigs never reach their eighth month, although theoretically the animal can live about 15 years. Modern hog raising seeks to emulate the efficiency levels of the poultry industry. In that quest, its technological center in the United States has shifted from the Midwest to a belt of large corporate farms in eastern North Carolina. In 1994 alone, that latter-day "hog heaven" sent nearly 10 million animals, worth a total of about a billion dollars, to market. The next step, pork processing and trade, is normally quite lucrative, for about 75 percent of a pig’s carcass can be made into salable cuts of meat. By-products, such as lard, bristles, gelatin, and cortisone, further enhance profitability.

For almost half a century, a spiced ham product high in fat has been a favorite canned food in the United States and many other countries. Spam, packaged by Geo. A. Hormel and Company of Austin, Minnesota, has a sales volume of close to 100 million cans a year. Since 1937, when it was put on the market, Hormel’s Spam has served as an economical source of meat protein for millions of people. In 1991, following a major trend in the American food industry, Spam Lite was introduced; this product, however, barely meets federal requirements for fat content reduction.

Weight- and cholesterol-conscious consumers in Europe and North America have had an impact on the pork industry (Bichard and Bruce 1989). Consumer demand calls for leaner cuts, including substantial fat trimming, in supermarket meat cases. There is also a strong motivation to develop hog breeds with less fat in their muscle tissue, which normally has 5 to 7 percent fat. Pork fat is higher in unsaturated fatty acids than beef, veal, or lamb fat. On the average, one 85-gram serving of pork contains about 79 milligrams of cholesterol.

Lard, as a cooking medium, has ceded its former importance to vegetable oils. In response to this development, a shift in hog breeds toward the Landrace and the Large White has occurred. Of the 15 breeds of swine listed in the 1930 USDA Agricultural Yearbook, more than half have now disappeared. Less efficient breeds have also lost ground in Europe, where half of the 66 surviving breeds are now rare, and only 40 of 100 different breeds occurring in China are considered to be economically valuable (Epstein 1969).

International trade in pig meat originates overwhelmingly in Europe. In place for many decades, the single biggest flow of cured and canned pork is from Denmark to the United Kingdom. But even before that trade emerged, bacon had become an integral element of the British breakfast. The word "bacon" is derived from Francis Bacon (1561–1626), whose family crest featured a pig. Japan, although traditionally not a major consumer of pig meat, has become a significant importer of European pork products, and the well-known prosciutto (cured ham), from the Province of Parma in Italy, is now found in upscale shops around the world. Much potential movement of processed pig meat is thwarted because of the prevalence of three diseases, found mainly in underdeveloped countries: foot-and-mouth disease, hog cholera, and African swine fever. In Haiti in the early 1980s, for example, an epidemic of African swine fever killed two-thirds of the country’s 1.2 million pigs. The surviving swine constituted a reservoir of the disease and were slaughtered. Then, disease-free swine were imported from the United States and distributed to some of Haiti’s 800,000 former pig owners.

Conclusion

The story of the pig in space and time is one of a multifaceted mutualism with humans. Its early roles, as a feeder on garbage or as a free-ranging consumer of mast in the forest, freed the pig from competing with people for the same food. Part of this mutualism was also hygienic because of the animal’s capacity for disposing of wastes. Transforming the least noble of materials into succulent protein, however, also engendered enough apparent disgust to ban the animal and its flesh in certain cultures. The pig is now found around the world under vastly different circumstances. In industrialized countries, questions of efficiency and fat control have become of paramount importance, and no other domesticated animal has undergone such major changes in the way it has been kept.

Daniel W. Gade

Bibliography

Anderson, Eugene N., Jr. 1988. The food of China. New Haven, Conn.

Baldwin, James A. 1983. Pre-Cookian pigs in Australia? Journal of Cultural Geography 4: 17–27.

Bichard, Maurice, and E. Ann Bruce. 1989. Pigmeat production worldwide. Outlook on Agriculture 18: 145–51.

Epstein, H. 1969. Domestic animals of China. Farnham Royal, England.

1984. Pig. In Evolution of domesticated animals, ed. I. L. Mason, 145–62. New York.

Gade, Daniel W. 1987. The Iberian pig in the Central Andes. Journal of Cultural Geography 7: 35–50.

Harris, Marvin. 1985. Good to eat: Riddles of food and culture. New York.

Hesse, Brian. 1990. Pig lovers and pig haters: Patterns of Palestinian pork production. Journal of Ethnobiology 10: 195–226.

Kim, Seung Og. 1994. Burials, pigs, and political prestige in northern China. Current Anthropology 35: 119–41.

Laurans, R. 1963. Le porc dans la société médiévale. Paris.

1976. Évolution de l’alimentation du porc domestique. I. L’alimentation traditionnelle. In Le porc domestique (Ethnozootechnie No. 16), ed. R. Laurans, 22–33. Paris.

Miller, Robert L. 1990. Hogs and hygiene. Journal of Egyptian Archaeology 76: 125–40.

Parsons, James J. 1962. The acorn-hog economy of the oak woodlands of southwestern Spain. Geographical Review 52: 211–35.

Pond, W. G. 1983. Modern pork production. Scientific American 248: 78–87.

Rappaport, R. A. 1967. Pigs for the ancestors. New Haven, Conn.

Ross, Eric B. 1983. The riddle of the Scottish pig. BioScience 33: 99–106.

Sauer, Carl O. 1952. Agricultural origins and dispersals. New York.

Simoons, Frederick J. 1991. Food in China: A cultural and historical inquiry. Boca Raton, Fla.

1994. Eat not this flesh: Food avoidances from prehistory to the present. Second edition. Madison, Wis.