Global Sheep and Lamb stocks |
|
(million head) |
|
People's Republic of China |
170.9 |
Australia |
102.7 |
European Union (15 nation) |
99.3 |
former Soviet Union |
65.3 |
India |
62.5 |
Iran |
54.0 |
Sudan |
49.0 |
New Zealand |
39.9 |
United Kingdom |
35.3 |
South Africa |
25.3 |
World
Total |
1079.0 |
Source: |
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. 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. Other countries, such as Wales, produce a smaller
proportion of the world market, but sheep nonetheless play an important role in
their economy. In some places, like Sardinia, sheep-breeding has become the
principal and characteristic activity.
In the UK, 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.[2]
Texas has by far the most sheep of any state,[3] but now
has only about one-tenth[4] of the almost 11 million
sheep it had in the 1940s.[5]
In the 21st century, in
some situations, sheep can provide a return on investment of up to 400% 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".
Grazing
sheep
Domestic sheep are
descended from the mouflon that is found from the mountains of Turkey to
southern Iran. Evidence for domestication dates to 9000 BCE in Iraq.[6] It has been found by DNA analysis to be one of two
ancestors of domestic sheep. Although the second ancestor has not been
identified, both the urial and argali have been ruled out.[7]
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 have 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.
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.[2]
Sheep testicles, sometimes
euphemistically called prairie oysters[citation needed],
are considered a delicacy in many parts of the world.
A flock of
sheep grazing in Montana, United States.
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 see talk page] 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.
Sheep
mating, called tupping.
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].
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."[8] For example, sheep in Yorkshire, England found a way to
get over cattle grids by rolling on their backs. A study published in National
Geographic (December 8) showed a sheep can remember the faces of fifty
other sheep for over two years.
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.[9]
Lambs of
some breeds are born with long tails which are cut off once they reach a
certain age.
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 [3][4]. Animals like goats and sheep may have evolved
horizontal pupils because better vision in the vertical plane may be beneficial
in mountainous environments[5].
This is a glossary of terms
that relate to sheep and domestic sheep. Note that some terms
have localised meanings, and may be used only in one geographical region, or
may mean slightly different things in different areas.
Two lambs
feeding from the milk from their mother.
Wikipedia
http://en.wikipedia.org/w/index.php?title=Domestic_sheep&action=history
http://www.gnu.org/copyleft/fdl.html