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"Sheep" redirects here. For other uses, see Sheep (disambiguation).
"Lamb" redirects here. For other uses, see Lamb (disambiguation).

Domestic sheep
A flock of sheep
Domesticated
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Mammalia
Order:
Artiodactyla
Family:
Bovidae
Subfamily:
Caprinae
Genus:
Ovis
Species:
O. aries
Binomial name
Ovis aries

Domestic sheep are ruminant quadrupeds of the family Bovidae and the genus Ovis. The most numerous species of their genus, they are most likely descended from the wild mouflon of Asia. Sheep were one of the earliest animals to be domesticated for agricultural purposes; primarily for their valuable fleece and meat. They continue to be vital livestock internationally, and are also occasionally raised for their pelts, as dairy animals, and as model organisms by science. A sheep's wool is the most widely used of any animal, and is harvested most commonly by shearing. Ovine meat is called "lamb" when culled from younger animals and "mutton" when from older ones. Sheep husbandry has a vast lexicon of terms, which varies considerably with region. Adult female sheep are referred to as "ewes", intact males as "rams", castrated males as "wethers", and younger sheep as "lambs". A group of sheep is called a "flock", "herd" or "mob".

Being a key animal in the history of farming, the sheep has a deeply-entrenched place in human culture. Sheep figure in many mythologies - such as the Golden Fleece - and major religions, especially the Abrahamic traditions. Sheep also find representation in much modern language and symbology.

Description

The stereotypical appearance of a sheep is of a thick, white fleece, white face and limbs, and curling horns (in rams). The sheep is related to the goat, both belonging to the goat antelope subfamily Caprinae, itself part of the bovine family. To the untrained eye, it is often difficult to differentiate sheep and goats by appearance. However, the genes of sheep and goats differ so greatly that cross-species hybrids rarely occur, and are always infertile. A hybrid of a ewe and a buck is called a sheep-goat hybrid, not to be confused with a geep, which is a genetic chimera.

Sheep have horizontal slit-shaped pupils. The narrower the pupil, the more accurate the depth perception of peripheral vision is; so narrowing it in one direction would increase depth perception in that plane.[1] [2] Animals like goats and sheep may have evolved horizontal pupils because better vision in the vertical plane may be beneficial in mountainous environments.[3]

Breeds

This Soay ram demonstrates the wide variance in sheep traits that belies the prototypical appearance of the animal.

There are many breeds of sheep, but these are generally sub-classable as wool class, hair class and sheep meat variety breeds. Dual-purpose breeds are bred for both wool and meat.

Major wool breeds include Merino, Rambouillet, Romney, Shetland, and Lincoln. Drysdale and Herdwick are bred specifically for carpet wool.

Breeds of meat sheep include Beltex, Suffolk, Portland, Hampshire, Columbia, Texel, and Montadale.

Breeders of dual-purpose wool class sheep concentrate on fast growth, multiple births, ease of lambing and hardiness. An easy-care sheep is the Coopworth that has long wool and good lamb meat production qualities. Other dual-use breed are the Corriedale and Shropshire. Sometimes sheep are used for both purposes equally and cross-breeding is practiced to maximise both outputs. For example, Merino ewes providing wool may be crossed with Suffolk rams to produce lambs which are robust and suitable for the meat market.

Hair class sheep are the original class of sheep in the world, developed for meat and leather. They are prolific and highly resistant to disease and parasites. Dorpers and Kahtahdins are composite breeds of wool and hair crosses with different degrees of wool/hair mixes within the hair class. True hair sheep such as St. Croix, Barbados Blackbelly, Mouflon, Santa Inez and Royal White shed their protective down fiber to an all hair coat in the Spring/Summer. Hair class sheep are becoming more popular for their no-shear aspects.

History

Dongxiang men haggling over sheep in Gansu Province

Evidence for the domestication of sheep dates to 9000 BC in Iraq.[4] DNA analysis has shown that domestic sheep are descended from two ancestor species, one of which is the mouflon. Although the second ancestor has not been identified, both the urial and argali have been ruled out.[5] The urial (O. vignei) is found from northeastern Iran to northwestern India. It has a higher number of chromosomes (58) than domestic sheep (54) which makes it an unlikely ancestor of the latter, but it interbreeds with the mouflon. The argali sheep (O. ammon) of inner Asia (Tibet, Himalayas, Altay Mountains, Tien-Shan and Pamir) has 56 chromosomes and the Siberian snow sheep (Ovis nivicola) has 52 chromosomes.

Evidence of early domesticated sheep has been found in PPNB Jericho and Zawi Chemi Shanidar. The fleece-bearing sheep are only found since the Bronze Age. Primitive breeds, like the Scottish Soay sheep have to be plucked (a process called rooing), instead of sheared, as the kemps are still longer than the soft fleece, or the fleece must be collected from the field after it falls out. The European mouflon (O. musimon) found on Corsica and Sardinia as well as the Cretan and the extinct Cypriot wild sheep are possibly descended from early domestic sheep that turned feral.

Cultural significance

Sheep and shepherds have played a significant role in Judeo-Christian religious texts since time immemorial. Here, sheep are seen in front of Jerusalem's Damascus Gate.

Sheep have had a strong presence within many cultures, especially in areas where they form the most common type of livestock in pastoralism.

A wide symbology relates to sheep in ancient art, traditions and culture. In Egyptian mythology the ram was the symbol of Heryshaf. Judaism uses many sheep references including the Passover lamb. Christianity uses sheep-related images, such as: Christ as the good shepherd, or as the sacrificed Lamb of God (Agnus Dei), the bishop's Pastoral, the lion lying down with the lamb (a reference to all of creation being at peace, without suffering, predation or otherwise). Easter celebrations in Greece and Romania traditionally feature a meal of Paschal lamb. Sheep also have considerable importance in Arab culture; Eid ul-Adha is a major annual festival in Islam in which a sheep is sacrificed.

A ram on the coat of arms of Gotland.

Herding sheep plays an important historico-symbolic part in the Jewish and Christian faiths, since Abraham, Isaac, Jacob, Moses, and King David all worked as shepherds.

The ram is the first sign of the Western zodiac, in which it is known as Aries. The sheep (or goat) also forms one of the animals associated with the 12-year cycle of in the Chinese zodiac, related to the Chinese calendar. Chinese tradition associates each animal with certain personality traits.

The raising of sheep for wool and meat became a major industry in colonial Australia and New Zealand and remains significant. As a result, sheep and sheep shearing have become an important part of the folklore and cultural tradition of these two countries. In New Zealand, sheep outnumber the human population 12 to 1.[6]

Sheep are often associated with obedience due to the widespread perception that they lack intelligence and their undoubted herd mentality, hence the pejorative connotation of the adjective 'ovine'. In George Orwell's satirical novel Animal Farm, sheep are used to represent the ignorant and uneducated masses of revolutionary Russia. The sheep are unable to be taught the subtleties of revolutionary ideology and can only be taught repetitive slogans such as "Four legs good, two legs bad" which they bleat in unison at rallies. An individual who is very unlike others in their society may be pejoratively labeled a "black sheep".

The rock group Pink Floyd wrote a song using sheep as a symbol for ordinary people, that is, everyone who isn't a pig or dog. People who accept overbearing governments have been pejoratively referred to as "sheeple".

In contemporary events, controversy has raged over a scientific study at the Oregon Health and Science University which, because of the unedited printing of a press-release by PETA in a British newspaper, has been accused of attempting to find a way to breed out the minority trait which causes some rams to prefer homosexual relations. Further investigation revealed it only attempts to study the genetics and circumstances which produce the phenomenon and not "cure" it.[7]

Economic importance

Global Sheep and Lamb stock
in 2005
Number in millions
1.  People's Republic of China170.9 (15.84%)
2.  Australia102.7 (9.52%)
3. European Union (15 nation)99.3 (9.2%)
4. Russia (former Soviet Union)65.3 (6.05%)
5.  India62.5 (5.79%)
6.  Iran54 (5%)
7.  Sudan49 (4.54%)
8.  New Zealand39.9 (3.7%)
9.  United Kingdom35.3 (3.27%)
10.  South Africa25.3 (2.34%)
World total1079.0
Source: UN Food and Agriculture Organization

Raising sheep was and is important to farmers in many economies, given that sheep can give milk (and its derivative products, such as cheese), wool, sheepskin (used for making clothes, footwear, rugs, and other coverings) and meat. Sheep droppings have even been sterilized and mixed with other traditional pulp materials to make paper.[8] In the 21st century, sheep retain considerable importance in the economies of several countries. After China, the largest producers of sheep products are in the southern hemisphere: Australia, New Zealand and the Patagonian regions of Argentina, Uruguay, and Chile. Sheep play an important role in the economies of a number of smaller countries, such as Wales. In some places, like Sardinia, sheep-breeding has become the principal and characteristic activity.

In the United Kingdom, the importance of the wool trade was so significant that in the upper chamber of parliament (the House of Lords), the Lord Chancellor sits on a bench known as the Woolsack. This is, as its name suggests, a sack of wool and confers the importance of the wool trade to the English economy at the time of its installation many centuries ago.

The economic importance of sheep in much of the United States has declined as it has become, in some cases, economically unviable to ranch sheep for wool.[9] Texas has by far the most sheep of any state,[10] but now has only about one-tenth[11] of the almost 11 million sheep it had in the 1940s.[12]

Sheep headcount in 2004

In the 21st century, in some situations, sheep can provide a return on investment of up to 400%[citation needed] of their cost annually (including reproduction gains). Sheep breeding has played a role in several historic conflicts, such as the Scottish Highland Clearances, the American range wars, and the English "enclosing of the commons".

As food

Main article: lamb (food)

Chefs and diners commonly know sheep meat prepared for food as lamb or mutton (compare the French word for "sheep": mouton).

Ewes' milk is used in the production of cheese and yogurt in many upland parts of the world. Well known sheep milk cheeses include the Roquefort of France, the brocciu of Corsica, the pecorino of Italy and the feta cheese of Greece. See Category:Sheep's-milk cheeses. Sheep milk contains lactose, and may trigger lactose intolerance in humans.[1]

Sheep testicles - called animelles or Lamb fries in culinary terms - are considered a delicacy in many parts of the world. They are sometimes confused with Rocky Mountain oysters which are exclusively the testicles of boars or bulls.

Behavior

A flock of sheep being herded through the streets

Some breeds of sheep exhibit a strong flocking behaviour. Flocking behaviour is advantageous to non-predatory animals; the strongest animals fight their way to the center of the flock[dubious – discuss] which offers them great protection from predators. It can be disadvantageous when food sources are limited and sheep are almost as prone to overgrazing a pasture as goats. In Iceland, where sheep have no natural predators, and grasses grow slowly, none of the various breeds of sheep exhibit a strong flocking behaviour[citation needed].

Sheep flocking behaviour is so prevalent in some English breeds that special names apply to the different roles sheep play in a flock. One calls a sheep that roams furthest away from the others an outlier, this sheep ventures further away from the safety of the flock to graze, due to a larger flight zone or a weakness that prevents it from obtaining enough forage when with the flock, while taking a chance that a predator, such as a wolf, will attack it first because of its isolation.

Another sheep, the bellwether, which never goes first but always follows an outlier[citation needed], signals to the others that they may follow in safety. When it moves, the others will also move. Traditionally this was a castrated ram (or wether) with a bell hung off a string around its neck[citation needed]. The tendency to act as an outlier, bellwether or to fight for the middle of the flock stays with sheep throughout their adulthood; that is unless they have a scary experience which causes them to increase their flight zone[citation needed].

Some sheep have shown problem-solving abilities. According to a spokesperson of the British National Sheep Association, "Sheep are quite intelligent creatures and have more brainpower than people are willing to give them credit for."[13] A herd in Yorkshire, England found a way to get over cattle grids by rolling on their backs.[13]

Sheep can become hefted to one particular pasture so they do not roam far from home. Since the outbreak of foot and mouth disease in the United Kingdom, transplanted sheep have had to be trained to stay in their grazing area.[14]

Sheep are also one of the many animals that can display a preference for homosexuality and are one of the few in which this occurrence has been systematically studied. It occurs in about eight percent of rams on average. Its occurrence does not seem to be related to dominance or flock hierarchy; rather the rams typical motor pattern for intercourse is merely directed at rams instead of ewes[15].

Terminology

A trio of lambs.

Sheep husbandry has existed in nearly every inhabited part of the globe, and the variations in cultures and languages which have kept sheep has produced a vast lexicon of unique terminology used to describe the practice. A few of the more major terms include:

  • Bale – A wool pack containing a specified weight of wool as regulated by industry authorities.
  • Bottle lamb or cade lamb – an orphan lamb reared on a bottle. Also poddy lamb or pet lamb.
  • Broken-mouth or broken-mouthed – an old sheep which has lost some of its incisor teeth.
  • CFA or cast for age – sheep culled because of their age (also see cull ewe).
  • Clip – all the wool from a flock (in Australian Wool Classing).
  • Comeback – the progeny of a mating of a Merino with a British longwool sheep.
  • Cull ewe – a ewe no longer suitable for breeding, and sold for meat.
  • Crutching – shearing parts of a sheep (especially the hind end of some woollier breeds such as Merino), to prevent fly-strike.
  • Dags – clumps of dried dung stuck to the wool of a sheep, which may lead to fly-strike. (Hence "rattle your dags!", meaning "hurry up!", especially used in Australia.)
  • Dagging – clipping off dags. See also crutching.
  • Draft ewe – a ewe too old for rough grazing (such as moorland), drafted (selected) out of the flock to move to better grazing, usually on another farm. Generally spelt draft, but in British Isles either as draft or draught.
  • Earmark – distinctive mark clipped out of the ear (sometimes a tattoo) to denote ownership.
  • Eartag – plastic or metal tag clipped to ear, with number or name, or (in European Union the official flock mark).
  • Ewe (Template:PronEng – like "you") – a female sheep, capable of producing lambs. In areas where gimmer or similar terms are used for young females, may refer to a female only after her first lamb. In some areas yow.
  • Fleece – the wool covering of a sheep.
  • Flock – a group of sheep (or goats). All the sheep on a property (in Australian Wool Classing; also all the sheep in a region or country. Sometimes called herd or mob.
  • Fold (or sheepfold) – a pen in which a flock is kept overnight to keep the sheep safe from predators, or to allow the collection of dung for manure.
  • Folding – confining sheep (or other livestock) onto a restricted area for feeding, such as a temporarily fenced part of a root crop field, especially when done repeatedly onto a sequence of areas.
  • Gimmer (Template:PronEng, not /dʒɪˈmɚ/) – a young female sheep, usually before her first lamb (especially used in the north of England). Also theave.
  • Hefting (or heafing) – the instinct in some breeds of keeping to a certain heft (or heaf – small local area) throughout their lives. Allows different farmers in an extensive landscape such as moorland to graze different areas without the need for fences, the ewes being scattered evenly over a wide area. Lambs usually learn their heft from their mothers.
  • Hogget (also hogg, hog or hoggat) – a yearling sheep.
  • In lamb – pregnant.
  • Lamb (Template:PronEng) – a young sheep in its first year. In many eastern countries there is a looser use of the term which may include older hoggets. Also the meat of younger sheep.
  • Lambing – the process of giving birth in sheep. Also the work of tending lambing ewes (shepherds are said to lamb their flocks).
  • Lamb marking – the earmarking, docking and castration of lambs.
  • Mob –sheep of the same breed that have run together under similar ervironmental conditions since the previous shearing (in Australian Wool Classing).
  • Monorchid – a male mammal with only one descended testicle, the other being retained internally. Monorchid sheep are less fertile than full rams, but have leaner meat than wethers.
  • Mule – a type of cross-bred sheep, both hardy and suitable for meat (especially in northern England). Usually bred from a Bluefaced Leicester ram on hardy mountain ewes such as Swaledales.
  • Mulesing – a practice in Australia of cutting off wrinkles from the crutch area of Merinos, to prevent fly-strike. Controversial, and illegal in other parts of the world. Named after a Mr Mules.
  • Mutton – the meat of an older sheep. Also an older female sheep to be used for this purpose. May refer to goat meat in eastern countries. Derived from the Anglo-Norman French word mouton (sheep).
  • Old-season lamb – a lamb a year old or more.
  • Ovine – the adjective applied to sheep, especially in technical language (for example "ovine anatomy"). Also any member of the genus Ovis.
  • Poddy lamb or pet lamb – an orphan lamb reared on a bottle. Also bottle lamb or cade lamb.
  • Raddle – a coloured marker strapped to the chest of a ram, to mark the backs of ewes he tups. Different rams may be given different colours. Also a verb ("that ewe's been raddled"). Also ruddy.
  • Ram – an uncastrated adult male sheep. Also tup.
  • Riggwelter – a sheep that has fallen onto its back and (usually because of the weight of its fleece) is unable to get up.
  • Ringing – the removal of a circle of wool from around the pizzle of a male sheep.
  • Ruddy – local Cumbrian term for raddle.
  • Shear – cut off the fleece. A sheep may be said to have been either sheared or shorn.
  • Shearling – a yearling sheep before its first shearing. Also teg.
  • Sheep – the species, or members of it. The plural is the same as the singular, and it can also be used as a mass noun. Normally used of individuals of any age, but in some areas only for those of breeding age.
  • Sheepdog or shepherd dog – a dog used to move and control sheep, often very highly trained. Other types of dog may be used just to guard sheep (see livestock guardian dog), and these are sometimes also called sheepdogs.
  • Shepherd – a stockperson or farmer who looks after sheep. Used even in areas where a group of sheep is called a flock.
  • Shepherding – herding sheep, or sheep husbandry more generally.
  • Slink – a very young lamb.
  • Stag – a ram castrated after about 6 months of age.
  • Stores – sheep (or cattle etc) in good average condition, but not fat. Usually bought by dealers to fatten for resale.
  • Sucker – an unweaned lamb.
  • Teg – a sheep in its second year. Also shearling.
  • Theave or theaf – a young female sheep, usually before her first lamb. Also gimmer.
  • Tup – an alternative term for ram.
  • Tupping – mating in sheep, or the mating season (autumn, for a spring-lambing flock).
  • Weaner – a young animal that has been weaned, from its mother, until it is about a year old.
  • Wether – a castrated male sheep (or goat).
  • Wigging – the removal of wool from around a sheep's eyes to prevent wool blindness.
  • Wool blind – when excessive wool growth interferes with the normal sight of a sheep.
  • Wool pack – a standard-sized woven nylon container manufactured to industry specifications for the transportation of wool.
  • Yow (Template:PronEng – rhymes with "how") – local form of ewe in some areas.

See also

References

  1. ^ MadSci Network, posted by Tim Susman, Staff Zoology, University of Minnesota, St. Paul, MN
  2. ^ MadSci Network posted by Tim Susman, Staff Zoology, University of Minnesota, St. Paul, MN
  3. ^ MadSci Network posted by Tim Susman, Staff Zoology, University of Minnesota, St. Paul, MN
  4. ^ Krebs, Robert E. & Krebs, Carolyn A (2003). Groundbreaking Scientific Experiments, Inventions & Discoveries of the Ancient World. Westport, CT: Greenwood Press. ISBN 0-313-31342-3.{{cite book}}: CS1 maint: multiple names: authors list (link)
  5. ^ Hiendleder S, Kaupe B, Wassmuth R, Janke A. (2002). "Molecular analysis of wild and domestic sheep questions current nomenclature and provides evidence for domestication from two different subspecies". Proceedings. Biological sciences, The Royal Society of London. {{cite web}}: Unknown parameter |accessmonthday= ignored (help); Unknown parameter |accessyear= ignored (|access-date= suggested) (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  6. ^ "The people of New Zealand". 'Society', Te Ara - the Encyclopedia of New Zealand. 09 June, 2006. {{cite web}}: Check date values in: |year= (help)CS1 maint: year (link)
  7. ^ Seattle Times
  8. ^ Sheeppoopaper.com
  9. ^ "Shear Artisans". San Angelo Standard-Times. 22 May, 2004. {{cite web}}: Check date values in: |year= (help)CS1 maint: year (link)
  10. ^ "Top Five Sheep & Lamb Producing States". National Agricultural Statistics Service. 28 January, 2005. {{cite web}}: Check date values in: |year= (help)CS1 maint: year (link)
  11. ^ "Sheep and Goats". National Agricultural Statistics Service. 27 January, 2006. {{cite web}}: Check date values in: |year= (help)CS1 maint: year (link)
  12. ^ "Sheep Herding". Handbook of Texas Online. 26 February, 2004. {{cite web}}: Check date values in: |year= (help)CS1 maint: year (link)
  13. ^ a b "Crafty sheep conquer cattle grids". BBC News. 30 July, 2004. Retrieved 2006-04-29. {{cite web}}: Check date values in: |year= (help)CS1 maint: year (link)
  14. ^ "Sheep taught to stay put". BBC News. 3 November, 2001. Retrieved 2006-04-29. {{cite web}}: Check date values in: |year= (help)CS1 maint: year (link)
  15. ^ OHSU
Look up sheep in Wiktionary, the free dictionary.
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Further reading

  • Juliet Clutton-Brock. A natural history of domesticated animals (London 1987).
  • Journal of Heredity. 1998 Mar-Apr;89(2):113-20. Analysis of mitochondrial DNA indicates that domestic sheep are derived from two different ancestral maternal sources: no evidence for contributions from urial and argali sheep. Hiendleder S, Mainz K, Plante Y, Lewalski H.
  • G.J. Syme & L.A. Syme. Social Structure in Farm Animals (Elsevier, Amsterdam, 1979).

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