Sheep

Sheep (pl.: sheep) or domestic sheep (Ovis aries) are a domesticated ruminant mammal typically kept as livestock. Although the term sheep can apply to other species in the genus Ovis, in everyday usage it almost always refers to domesticated sheep. Like all ruminants, sheep are members of the order Artiodactyla, the even-toed ungulates. There are around 1.2 billion domestic sheep as of 2019, making them easily the most common species of sheep. An adult female is referred to as a ewe ( yoo); an intact male as a ram, occasionally a tup; a castrated male as a wether; and a young sheep as a lamb. Sheep are most likely descended from the wild mouflon of Europe and Asia, with Iran being a geographic envelope of the domestication center. One of the earliest animals to be domesticated for agricultural purposes, sheep are raised for fleeces, meat (lamb, hogget, or mutton), and sheep milk. A sheep's wool is the most widely used animal fiber, and is usually harvested by shearing. Ovine meat is called lamb and mutton, with lamb describing meat from younger animals and mutton meat from older ones. Sheep continue to be important for wool and meat today, and are also occasionally raised for pelts, as dairy animals, or as model organisms for science. Sheep husbandry is done throughout the majority of the inhabited world. It was central to agriculture and textiles throughout Eurasia for millennia. In the 21st century, Australia, New Zealand, nations of southern and western South America, South Africa, and the British Isles are most closely associated with sheep production. More recently, China and India host among the largest flocks by absolute count, if as a smaller proportion of their economy. There is a large lexicon of unique terms for sheep husbandry which vary considerably by region and dialect. Use of the word sheep began in Middle English as a derivation of the Old English word scēap. A group of sheep is called a flock. Many other specific terms for the various life stages of sheep exist, generally related to lambing, shearing, and age. As a key animal in the history of farming, sheep have an entrenched place in human culture. Sheep terminology and idiom are common in language and symbolism. As livestock, sheep are most often associated with pastoral, Arcadian imagery. Sheep figure in many mythologies—such as the Golden Fleece—and major religions, especially the Abrahamic traditions. In both ancient and modern religious ritual, sheep are used as sacrificial animals.

History

The exact line of descent from wild ancestors to domestic sheep is unclear. The most common hypothesis states that Ovis aries is descended from the Asiatic (O. gmelini) species of mouflon; the European mouflon (Ovis aries musimon) is a direct descendant of this population. Sheep were among the earliest animals to be domesticated by humankind (along with dogs, which were domesticated 10 to 20 thousand years earlier); the date of domestication is estimated to fall between 11,000 and 9000 BC in Mesopotamia, from which it spread to Mehrgarh in the Indus Valley around 7000 BC. The rearing of sheep for secondary products, and the resulting breed development, began in either southwest Asia or western Europe. Initially, sheep were kept for meat, milk, and skins rather than fleece. Archaeological evidence from statuary found at sites in Iran suggests that selection for woolly sheep may have begun around 6000 BC, while the earliest woven wool garments have been dated to around 4000 BC, two thousand years later. Sheep husbandry spread quickly in Europe. Excavations show that in about 6000 BC, during the Neolithic period, the Castelnovien people in Châteauneuf-les-Martigues, near present-day Marseille in the south of France, were among the first Europeans to keep domestic sheep. Practically from its inception, ancient Greek civilization relied on sheep as primary livestock, and the Greeks were even said to name individual animals. Ancient Romans kept sheep on a wide scale, and were an important agent in the spread of sheep raising. Pliny the Elder, in his Natural History (Naturalis Historia), speaks at length about sheep and wool. European colonists spread the practice to the New World from 1493 onwards.

Characteristics

Domestic sheep are relatively small ruminants, usually with a crimped hair called wool and often with horns forming a lateral spiral. They differ from their wild relatives and ancestors in several respects, having become uniquely neotenic as a result of selective breeding by humans. A few primitive breeds of sheep retain some of the characteristics of their wild cousins, such as short tails. Depending on breed, domestic sheep may have no horns at all (i.e. polled), or horns in both sexes, or in males only. Most horned breeds have a single pair, but a few breeds may have several horns, such as Jacob sheep. Another trait unique to domestic sheep as compared to wild ovines is their wide variation in color. Wild sheep are largely variations of brown hues, and variation within species is extremely limited. Colors of domestic sheep range from pure white to dark chocolate brown, and even spotted or piebald. Sheep keepers also sometimes artificially paint "smit marks" onto their sheep in any pattern or color for identification. Selection for easily dyeable white fleeces began early in sheep domestication, and as white wool is a dominant trait it spread quickly. However, colored sheep do appear in many modern breeds, and may even appear as a recessive trait in white flocks. While white wool is desirable for large commercial markets, there is a niche market for colored fleeces, mostly for handspinning. The nature of the fleece varies widely among the breeds, from dense and highly crimped, to long and hairlike. There is variation of wool type and quality even among members of the same flock, so wool classing is a step in the commercial processing of the fibre.

… excerpt ends here. Continue reading the full article.