Sheep - Wikipedia. The sheep (Ovis aries) is a quadrupedal, ruminantmammal typically kept as livestock. Like all ruminants, sheep are members of the order Artiodactyla, the even- toed ungulates. Numbering a little over one billion, domestic sheep are also the most numerous species of sheep. An adult female sheep is referred to as a ewe (), an intact male as a ram or occasionally a tup, a castrated male as a wether, and a younger sheep as a lamb. Sheep are most likely descended from the wild mouflon of Europe and Asia. One of the earliest animals to be domesticated for agricultural purposes, sheep are raised for fleece, meat (lamb, hogget or mutton) and milk. A sheep's wool is the most widely used animal fiber, and is usually harvested by shearing. Ovine meat is called lamb when from younger animals and mutton when 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 practised throughout the majority of the inhabited world, and has been fundamental to many civilizations. In the modern era, Australia, New Zealand, the southern and central South American nations, and the British Isles are most closely associated with sheep production. Sheepraising has a large lexicon of unique terms which vary considerably by region and dialect. Use of the word sheep began in Middle English as a derivation of the Old English word sc. A group of sheep is called a flock, herd or mob. Many other specific terms for the various life stages of sheep exist, generally related to lambing, shearing, and age. Being a key animal in the history of farming, sheep have a deeply entrenched place in human culture, and find representation in much modern language and symbology. As livestock, sheep are most often associated with pastoral, Arcadian imagery. Sheep figure in many mythologies. In both ancient and modern religious ritual, sheep are used as sacrificial animals. Characteristics. Domestic sheep are relatively small ruminants, usually with a crimped hair called wool and often with horns forming a lateralspiral. Domestic sheep differ from their wild relatives and ancestors in several respects, having become uniquely neotenic as a result of selective breeding by humans. Depending on breed, domestic sheep may have no horns at all (i. Most horned breeds have a single pair, but a few breeds may have several. 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. However, colored sheep do appear in many modern breeds, and may even appear as a recessive trait in white flocks. Free radicals, antioxidants and functional foods: Impact on human health V Lobo, A Patil, A Phatak, N Chandra Department of Botany, Birla College, Kalyan - 421 304.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. Suffolks are a medium wool, black- faced breed of meat sheep that make up 6. U. S. Their rate of growth and mature weight is a heritable trait that is often selected for in breeding. As with other ruminants, the front teeth in the lower jaw bite against a hard, toothless pad in the upper jaw. These are used to pick off vegetation, then the rear teeth grind it before it is swallowed. There are eight lower front teeth in ruminants, but there is some disagreement as to whether these are eight incisors, or six incisors and two incisor- shaped canines. This means that the dental formula for sheep is either 0. Food availability and food hygiene are compromised every day by diseases and pests that plague plants and animals as well as various types of contaminants. InformationWeek.com: News, analysis and research for business technology professionals, plus peer-to-peer knowledge sharing. Engage with our community. Save on EarthLink's award-winning Internet services for your home: dial-up, DSL, high-speed cable & more. Plus, web hosting & software. Taking These Common Painkillers? You're Playing 'Russian Roulette' With Your Heart. In the first few years of life one can calculate the age of sheep from their front teeth, as a pair of milk teeth is replaced by larger adult teeth each year, the full set of eight adult front teeth being complete at about four years of age. The front teeth are then gradually lost as sheep age, making it harder for them to feed and hindering the health and productivity of the animal. For this reason, domestic sheep on normal pasture begin to slowly decline from four years on, and the life expectancy of a sheep is 1. A few breeds tend to have considerable wool on the face; for some individuals of these breeds, peripheral vision may be greatly reduced by . In general, sheep have a tendency to move out of the dark and into well- lit areas. Sheep also have an excellent sense of smell, and, like all species of their genus, have scent glands just in front of the eyes, and interdigitally on the feet. The purpose of these glands is uncertain. However, they are separate species, so hybrids rarely occur, and are always infertile. A hybrid of a ewe and a buck (a male goat) is called a sheep- goat hybrid (only a single such animal has been confirmed), and is not to be confused with the sheep- goat chimera, though both are known as geep. Visual differences between sheep and goats include the beard of goats and divided upper lip of sheep. Sheep tails also hang down, even when short or docked, while the short tails of goats are held upwards. Also, sheep breeds are often naturally polled (either in both sexes or just in the female), while naturally polled goats are rare (though many are polled artificially). The Daily Show is an Emmy and Peabody Award-winning program that looks at the day's top headlines through a sharp, reality-based lens. Along with the help of The Best. Males of the two species differ in that buck goats acquire a unique and strong odor during the rut, whereas rams do not. Other features used when classifying sheep include face color (generally white or black), tail length, presence or lack of horns, and the topography for which the breed has been developed. This last point is especially stressed in the UK, where breeds are described as either upland (hill or mountain) or lowland breeds. Fine wool breeds are those that have wool of great crimp and density, which are preferred for textiles. Most of these were derived from Merino sheep, and the breed continues to dominate the world sheep industry. Downs breeds have wool between the extremes, and are typically fast- growing meat and ram breeds with dark faces. Long wool breeds are the largest of sheep, with long wool and a slow rate of growth. Long wool sheep are most valued for crossbreeding to improve the attributes of other sheep types. For example: the American Columbia breed was developed by crossing Lincoln rams (a long wool breed) with fine- wooled Rambouillet ewes. Coarse or carpet wool sheep are those with a medium to long length wool of characteristic coarseness. Breeds traditionally used for carpet wool show great variability, but the chief requirement is a wool that will not break down under heavy use (as would that of the finer breeds). As the demand for carpet- quality wool declines, some breeders of this type of sheep are attempting to use a few of these traditional breeds for alternative purposes. Others have always been primarily meat- class sheep. Dual- purpose breeds that may primarily be meat or wool sheep are often used secondarily as milking animals, but there are a few breeds that are predominantly used for milking. These sheep produce a higher quantity of milk and have slightly longer lactation curves. Hair sheep are similar to the early domesticated sheep kept before woolly breeds were developed, and are raised for meat and pelts. Some modern breeds of hair sheep, such as the Dorper, result from crosses between wool and hair breeds. For meat and hide producers, hair sheep are cheaper to keep, as they do not need shearing. The Rare Breeds Survival Trust of the UK lists 2. The Livestock Conservancy lists 1. Most breeds prefer to graze on grass and other short roughage, avoiding the taller woody parts of plants that goats readily consume. When sheep graze, vegetation is chewed into a mass called a bolus, which is then passed into the rumen, via the reticulum. The rumen is a 1. After the first three chambers, food moves into the abomasum for final digestion before processing by the intestines. The abomasum is the only one of the four chambers analogous to the human stomach, and is sometimes called the . The ability to thrive solely on pasture (even without hay) varies with breed, but all sheep can survive on this diet. Feed provided to sheep must be specially formulated, as most cattle, poultry, pig, and even some goat feeds contain levels of copper that are lethal to sheep. Ideal pasture for sheep is not lawnlike grass, but an array of grasses, legumes and forbs. Common plants toxic to sheep are present in most of the world, and include (but are not limited to) cherry, some oaks and acorns, tomato, yew, rhubarb, potato, and rhododendron. With a much narrower face, sheep crop plants very close to the ground and can overgraze a pasture much faster than cattle. By disturbing the natural state of pasture, sheep and other livestock can pave the way for invasive plants. However, sheep also prefer to eat invasives such as cheatgrass, leafy spurge, kudzu and spotted knapweed over native species such as sagebrush, making grazing sheep effective for conservation grazing. Three trials demonstrated that grazing lambs were just as effective as herbicides in controlling winter weeds. Entomologists also compared grazing lambs to insecticides for insect control in winter alfalfa. In this trial, lambs provided insect control as effectively as insecticides. The dominance hierarchy of sheep and their natural inclination to follow a leader to new pastures were the pivotal factors in sheep being one of the first domesticated livestock species. Relationships in flocks tend to be closest among related sheep: in mixed- breed flocks, subgroups of the same breed tend to form, and a ewe and her direct descendants often move as a unit within large flocks. Lambs learn the heft from ewes and if whole flocks are culled it must be retaught to the replacement animals. Cornered sheep may charge and butt, or threaten by hoof stamping and adopting an aggressive posture. This is particularly true for ewes with newborn lambs. This method of moving sheep works best with smaller flocks. Farmers exploit flocking behavior to keep sheep together on unfenced pastures such as hill farming, and to move them more easily. Established in 1. Connelly and Associates, Inc. We also offer services in support of engineering and environmental consultants as well as HVAC contractors. Services. Geotechnical - Precisely collecting data without distorting results through our knowledge of local geology. Read More > Environmental - Performing subsurface environmental investigations to determine existence of contamination. Read More > Geothermal- Read More > Equipment. 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