swine

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swine,

name for any of the cloven-hoofed mammals of the family Suidae, native to the Old World. A swine has a rather long, mobile snout, a heavy, relatively short-legged body, a thick, bristly hide, and a small tail. The name swine is applied mainly to domestic animals, which are also known as hogs. Sometimes these are called pigs, a term which in the United States is more correctly reserved for the young animals. Boar is a term for a male domestic swine suitable for breeding, but the term wild boar is used for the common wild swine, Sus scrofa, of Eurasia and N Africa. There are no true swine native to the New World, although a similar, related animal, the peccarypeccary
, small wild pig, genus Tayassu, the only pig native to the Americas. Although similar in appearance to Old World pigs, peccaries are classified in a family of their own because of anatomical differences.
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, is found in the deserts and rain forests of parts of N and S America. The so-called wild hogs found in parts of the United States are descendants of the European wild boar, introduced for sport hunting, or hybrid offspring of escaped domestic hogs; in many areas of their range they are a significant agricultural pest.

The wild boar may reach a height of 3 ft (90 cm) and a length of 5 ft (150 cm). It has 9-in. (30-cm) tusks and a fierce disposition. Now rare in Europe, it is still common in parts of Asia. The Eurasian wild boar is believed to have been domesticated in Anatolia c.7000 B.C. or earlier. Modern domesticated hogs appear to be descended chiefly from this wild boar, with European strains supplanting Near Eastern ones after domesticated swine were introduced into Europe, and with some much later admixture of the smaller Asian domesticated swine that originated from a different subspecies in China about 8,000–9,000 years ago. Hogs were introduced into the Americas by Columbus on his second voyage in 1493; in 1609 hogs were shipped to the Jamestown colony from England.

Economic Importance

Swine are valuable for their flesh, prepared as ham, bacon, and pork, and for their fat (lard); they also provide many other products, e.g., leather for gloves, footballs, and other articles, and bristles for brushes. Hogs are commonly grouped as meat-type or lard-type, with the former dominating the U.S. farms. Hogs are raised in nearly all parts of the United States, but the corn belt of the Midwest is the chief hog-raising area, with Iowa by far the leading hog-producing state.

A great majority of U.S. hog production has moved from open pens to enclosed, mechanized facilities. The trend is toward huge, factorylike hog farms where swine are born and bred inside structures that feed, water, and dispose of wastes while controlling ambient temperature. Though hogs will eat almost any food, modern swine feed is nutritionally balanced to produce rapid and healthy growth. Based on a mix of corn and soybeans, the feed is supplemented by minerals, vitamins, and antibiotics. The giant modern farms produce enormous amounts of hog waste; this has become of increasing concern as a potential source of water pollution.

Diseases of Swine

Hogs are probably susceptible to a greater number of diseases than any other domestic animal. Respiratory and parasitic ailments are major problems, particularly with limited exercise and lack of sunlight. With an estimated 65% to 85% of U.S. herds exposed to swine pneumonia viruses, drugs are increasingly important to the hog industry. Some swine diseases are transmissible to humans. Among them are brucellosis, trichinosis, and cysticercosis. The last two are supposedly the basis of the first food sanitation codes.

Classification

Swine are classified in the phylum ChordataChordata
, phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal skeletal support at some stage of their development. Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals.
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, subphylum Vertebrata, class Mammalia, order Artiodactyla, family Suidae.

Bibliography

See J. Blakely, The Science of Animal Husbandry (3d ed. 1982); O. Schell, Modern Meat (1984).

Swine

 

a domestic artiodactyl of the genus Sus of the family Suidae. Domestic swine are derived from different subspecies of European and Asian boars, and consequently indigenous swine breeds are divided into those of European origin and those of Asiatic origin. Modern cultural breeds descended from these two groups.

Swine were domesticated in the Neolithic period (fifth to third millennia B.C.). In the process of domestication and extended breeding their external appearance, fertility, and productivity were greatly altered. However, cultural breeds of swine have retained the biological characteristics of the genus Sus, including poor eyesight, excellent hearing, a keen sense of smell, and the ability to swim well. Fertility has increased among cultural swine breeds, and the breeds mature and fatten more quickly.

Among farm animals, swine are the most fertile and the earliest to mature. With proper feeding and care, most modern breeds produce ten to 12 young or more per farrow. Sows are bred at the age of nine or ten months, producing their first litter at 13 to 15 months. The average weight of the young at birth is 1.2–1.3 (maximum 1.6) kg. For 1 kg of weight gain, swine are fed 4–5 kg of grain feed; for an equal weight gain, cows are fed 25 percent more and sheep 50 percent more.

Swine breeds vary considerably in productivity, appearance, and size. Depending on productivity goals, three types of fattened swine are distinguished: the meat, bacon, and meat-and-lard types. The meat type is internationally the most popular. Swine are raised throughout the world, with more than 100 breeds in existence. The USSR raises 24 breeds; the USA, 17; Great Britain, 13; the Federal Republic of Germany, 7; Hungary, 6; Austria, Sweden, Norway, Switzerland, the Netherlands, and Belgium, two or three each; and Denmark, one. In 1972 the world swine population numbered 680 million; in 1975 the USSR had 72.2 million swine (see ).

REFERENCES

Red’kin, A. P. Svinovodstvo. Moscow, 1958.
Volkopialov, B. P. Svinovodstvo, 4th ed. Leningrad, 1968.
Savich, I. A. Svinovodstvo, 3rd ed. Moscow, 1971.
Svinovodstvo. Moscow, 1974.

swine

[swīn]
(agriculture)
A domesticated member of the family Suidae.
(vertebrate zoology)
Any of various species comprising the Suidae.