sheep(redirected from sheep itch mite)
Also found in: Dictionary, Thesaurus, Medical, Legal.
sheep,common name for many species of wild and domesticated ruminant mammals of the genus Ovis of the Bovidae, or cattle, family. The male is called a ram (if castrated it is a wether), the female is called a ewe, and their offspring is a lamb. Wild sheep, found in mountainous parts of Asia, North America, and the Mediterranean region, are agile rock climbers with large, spiraling horns. They do not bear wool. Among those species are the Asian argali, the Barbary sheep, or aoudad, of North Africa, and the North American bighornbighorn
or Rocky Mountain sheep,
wild sheep, Ovis canadensis, of W North America, formerly plentiful in mountains from SW Canada to N Mexico. Indiscriminate hunting, disease, and scarcity of food enormously reduced its numbers by the mid-20th cent.
..... Click the link for more information. , or Rocky Mountain sheep, found from SW Canada to N Mexico.
Sheep were first domesticated c.7,000 years ago, and the first use of their fleeces for wool is dated at c.4000 B.C. Descendants of Roman flocks figured in the evolution of the Merino type in Spain. The present-day breeds of domesticated sheep—which vary greatly because they were developed for different purposes and environments—are all thought to be derived chiefly from the wild mouflon of Sardinia and Corsica and from the urial of Asia. Sheep are bred for their woolwool,
fiber made from the fleece of the domestic sheep. Composition and Characteristics
Wool consists of the cortex, overlapping scales (sharper and more protruding than those of hair) that may expand at their free edges causing fibers to intermesh; elasticum, the
..... Click the link for more information. , meat (muttonmutton,
flesh of mature sheep prepared as food (as opposed to the flesh of young sheep, which is known as lamb). Mutton is deep red with firm, white fat. In Middle Eastern countries it is a staple meat, but in the West, with the exception of Great Britain, Australia, and New
..... Click the link for more information. or lamb, according to age), skins, and, in certain parts of Europe and the Middle East, their milk, from which cheese is made. They are found mostly in temperate climates and thrive on roughages. Most sheep mate in the fall, and the lambs, born five months later, are called spring lambs. Among the important breeds are the Columbia, CotswoldCotswold sheep,
large, white-faced, hornless breed with a broad, flat back, moderately deep body, heavy fleece, and long, coarse wool hanging in ringlets. It was originated in the Cotswold Hills in England. The Cotswold is often crossed with the Merino and Rambouillet breeds.
..... Click the link for more information. , DorsetDorset sheep,
medium-sized breed developed in England; the only major breed in which both rams and ewes are horned. It has been introduced into many areas of the United States, although it has failed to gain widespread popularity there.
..... Click the link for more information. , HampshireHampshire sheep,
large sheep bred originally in Hampshire, England, by crossing Southdowns, Cotswolds, and other breeds. Hampshires are large in size and hornless, have black faces and legs, and are characterized by rapid growth.
..... Click the link for more information. , KarakulKarakul sheep
, breed native to central Asia. The newborn lambs usually have tightly curled black fur and are skinned before they are three days old to provide the commercial lambskin for which the sheep are raised. The finest pelts are often obtained from unborn lambs.
..... Click the link for more information. , LeicesterLeicester sheep
, breed of sheep originated from native stock as mutton producers in Leicestershire, England, by the English livestock breeder Robert Bakewell (c.1755). English Leicesters have white faces and legs, broad backs, and thick flesh.
..... Click the link for more information. , LincolnLincoln sheep,
very large-bodied, white-faced, hornless breed having coarse wool, developed in England. It has made considerable contributions to the American sheep industry in the parentage of other breeds and is widely raised in several countries of the Southern Hemisphere.
..... Click the link for more information. , MerinoMerino sheep
, breed intermediate in body size having fine wool, developed in Spain. These sheep are noted for their hardiness and their herding instincts and have been used as parents of several other breeds, notably the Rambouillet of France. Three strains have been developed.
..... Click the link for more information. , OxfordOxford sheep,
relatively large-bodied, hornless breed developed in England using crosses between Hampshire and Cotswold sheep. The breed was selected for size and productivity. It has not had widespread popularity in the United States.
..... Click the link for more information. , RambouilletRambouillet sheep
, fine-wool breed developed in France from the Spanish Merino sheep. It has become very popular in the United States and is the foundation of most of the Western range flocks.
..... Click the link for more information. , ShropshireShropshire
, county (1991 pop. 401,600), 1,348 sq mi (3,491 sq km), W England; administratively, Shropshire is a unitary authority (since 2009). It is also sometimes called Salop. The adminstrative center is Shrewsbury.
..... Click the link for more information. , SouthdownSouthdown sheep,
mutton breed of sheep originated on the South Downs of Sussex, England, and now raised throughout the world. It is a small sheep, the most thickset of all breeds, and it is valued for the meatiness of the lamb carcasses.
..... Click the link for more information. , and Suffolk sheepSuffolk sheep,
relatively large breed, developed in England, well-known for its high quality meat. Considered to be a recent introduction to the United States, the breed has many desirable qualities and is becoming widely accepted there.
..... Click the link for more information. .
Sheep 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.
..... Click the link for more information. , subphylum Vertebrata, class Mammalia, order Artiodactyla, family Bovidae.
See M. E. Ensminger, Sheep and Wool Science (4th ed. 1970); N. D. May, The Anatomy of the Sheep (3d ed. 1970); publications of the U.S. Dept. of Agriculture.
a domestic ruminant artiodactyl of the genus Ovis of the family Bovidae. Sheep are descended from wild species of sheep, including the mouflon (Ovis musimon) and the argali (Ovis ammon), which were domesticated more than 8,000 years ago. The evolution of domestic sheep primarily involved changes in the woolly covering and the body shape.
Sheep are 55–100 cm high at the shoulders and measure 60–100 cm long from the occiput to the rump. Ewes weigh 30–100 kg, and rams 60–180 kg. The rams of most breeds have large horns; the ewes are hornless or have small horns. The head has a straight or, sometimes, hook-nosed profile. Its lower part is pointed, the lips are thin and quite mobile, and the incisors are placed at an oblique angle to the jaw. This head structure enables sheep to graze very close to the ground, making better use than other animals of the pasture. Adult sheep have 32 teeth. Replacement of milk teeth begins at the age of 12 to 18 months and ends between the ages of 3½ and four years. The legs are strong, enabling the sheep to wander extensively. A sheep may be white, black, rufous, or gray. Sheep with a fine or semifine fleece are usually white.
Sheep are classified according to shape of their tails as being short-thin-tailed (the tail is thin, does not reach the tarsal joint, and has ten to 12 vertebrae), long-thin-tailed (the tail is thin, reaches the tarsal joint or sometimes lower, and has 20 to 22 vertebrae and fatty deposits), and fat-tailed (the tail has five or six vertebrae, and there are fatty deposits on the rump and around the tail).
Under favorable conditions, the life-span of sheep is 14 or 15 years; on farms they are used for six to eight years. Sexual maturity is attained at five to seven months, and the animals are allowed to mate at 15 to 18 months. With natural mating, 60 to 70 ewes are assigned to one ram; with artificial insemination, the sperm of one ram is used to inseminate more than 3,000 ewes over a period of 45 days. Gestation lasts between 145 and 155 days. Most ewes bear one lamb; some yield two or three. Romanov ewes produce as many as five young. Newborn lambs weigh 3–5 kg. Growth is completed after two to four years.
The fleece of coarse-wooled sheep consists of a mixture of coarse fibers, 100–200 microns (μ) in diameter, and thinner downy fibers. The coat of fine-wooled sheep consists of homogeneous downy fibers having an average diameter of 25 μ. The wool of fine-wooled sheep is 5–9 cm long, that of semifine-wooled breeds is up to 40 cm long, and that of coarse-wooled breeds is 10–15 cm long. The annual clip from fine-wooled sheep is 5–6 kg (record clip, 31.7 kg), from semifine-wooled sheep 3–6 kg, and from coarse-wooled sheep 1–4 kg. The yield of pure wool after washing is 30–50 percent from fine-wooled breeds, 50–65 percent from semifine-wooled breeds, and 55–75 percent from coarse-wooled breeds. Fine-wooled and semifine-wooled sheep are clipped once a year, in the spring; coarse-wooled sheep are clipped in both the spring and autumn. The best meat and wool breeds are slaughtered at five to seven months of age and yield carcasses weighing 18–22 kg. Ewes produce 50–200 kg of milk per lactation (in some breeds up to 500 kg).
Breeding work with sheep includes selection, culling, and crossbreeding and is directed toward obtaining and rearing animals with desirable qualities. The principal feeds are grasses from natural and cultivated pastures, hay (mainly small-stalked), spring straw, silage, and concentrates. Sheep are pastured from early spring to late autumn; in regions with very little snow or hot climates, the animals may pasture year-round. They are kept in special pens; structures are also set up in seasonal pastures. Sheep tolerate various air temperatures well and may be kept in high-altitude pastures. They are very sensitive to dampness and are subject to catarrhal disorders, helminthiases, and foot rot. Sheep are raised in almost all countries.
REFERENCESSee references under .
G. R. LITOVCHENKO
What does it mean when you dream about sheep?
Dreaming about sheep may indicate the dreamer feels uncreative and lacks initiative to venture out on his or her own. The dreamer may be just following along, letting others direct his or her life.
["Sheep, a Computer Algebra System for General Relativity", J.E.F. Skea et al in Proc First Brazilian School on Comp Alg, W. Roque et al eds, Oxford U Press 1993, v2].