Sheep( Small Ruminants) Sheep from Animal Kingdom
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Sheep( small ruminants) The history of the domesticated sheep traces back to between 11000 and 9000 BC, and the domestication of the wild mouflon( Ovis orientalis). Sheep are thought to be one of the first animals domesticated by humans Mouflon ram Ewe Sheep from animal kingdom . Domesticated Scientific classification Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Artiodactyla Family: Bovidae Subfamily: Caprinae Genus: Ovis Species: O. aries Terminology of sheep. Lamb and mutton Lamb is also the term for the flesh of a young domestic sheep eaten as food. The meat from a sheep that is older than 12 months is called mutton. Ewes A female sheep is called a ewe. A young female is called a ewe lamb. The process of giving birth to lambs is called lambing. Another word for birthing is parturition. Another word for pregnancy is gestation. Rams A male sheep is called a ram. Buck is the slang term for ram. A young male is called a ram lamb. In parts of the United Kingdom, a ram is called a tup and the mating season is called tupping. Wethers A castrated male sheep is called a wether. Wethers are less aggressive than rams. Yearling A yearling is an animal between 1 and 2 years of age that may or may not have produced offspring. In other countries, a yearling ewe is called a hogget, shearling, gimmer, theave, or teg. Shepherd A shepherd is a person who cares for sheep. Sheep breeds It is difficult to know how many breeds of sheep there are in the world, as only developed countries usually maintain breed registries. However, it is believed that there are more breeds of sheep than breeds of any other livestock species, with the exception of poultry. Worldwide, it is estimated that there are more than 1000 distinct sheep breeds. There are more than 50 breeds in the United States alone Sheep come in all different sizes, shapes, and colors, and there are many ways to classify them: according to their primary purpose (meat, milk, or wool), the type of coat they have or fibers they grow (fine, medium, long or carpet wool; or hair), the color of their faces (black, white, red, or moddled), and/or by specific physical or production characteristics. Fine wool sheep Fine wool sheep produce wool fibers with a very small fiber diameter, usually 20 microns or less. Fine wool sheep account for more than 50 percent of the world's sheep population. Found throughout Australia, South Africa, South America, and the Western United States, most sheep of this type are Merino. Fine wool ewes (Rambouillet) Long wool sheep Long wool sheep produce long-stapled wool with a large fiber diameter, usually greater than 30 microns. Long wool sheep are best adapted to cool, high rainfall areas with abundant forage. They are commonly raised in England, Scotland, New Zealand. Long wooled rams (Romney and Lincoln) Medium wool meat sheep Meat or "mutton-type" sheep produce wool, mostly medium (or long), but are raised more for their meat qualities. Medium wool sheep account for about 15 percent of the world's sheep population. The most popular meat breeds in the U.S. are Dorset, Hampshire, Shropshire, Southdown, and Suffolk. Medium wool ewes (Texel) Carpet wool sheep The coarsest grade of wool (usually over 38 microns) is used in the manufacture of carpets. Carpet wool breeds are usually double-coated, with a coarse long outer coat for protection against the elements. They are generally adapted to extreme environments. Carpet wool breeds found in the U.S. include Icelandic, Karakul, Navajo Churro, and Scottish Blackface. Hair Sheep Some breeds lack wool and are covered with hair instead, like their wild ancestors. Some hair sheep have pure hair coats, whereas others have coats that contain a mixture of hair and wool fibers that shed naturally. Hair sheep are found mostly in Africa and the Caribbean, but are also raised in temperate climates, such as the U.S. and Canada. Hair sheep Fat-tailed sheep Fat tailed or fat-rumped sheep are so-named because they can store large amounts of fat in the tail and region of the rump. Fat-tailed sheep are found mostly in the extreme environments in Africa, the Middle East, and Asia. They grow wool, but are raised primarily for meat or milk production. Fat-tailed sheep comprise 25 percent of the world's sheep population. The only fat-tailed sheep in the U.S. is the Karakul. The Awassi, a fat-tail sheep from the Middle East was recently introduced to the U.S. via semen and embryos. Fat-rumped rams (Turki) Short or rat-tailed breeds Short or rat-tailed breeds originate primarily from Scandinavia and Northern Europe. Their tails are thin and free of wool and do not need docked. They tend to be prolific. Examples of these breeds include Finn Sheep, Romanov, East Friesian, Shetland, Icelandic, and Soay. Icelandic sheep Prolific breeds some sheep breeds are known for their prolificacy or high birth rates. Some were found to be naturally prolific whereas selection has resulted in the high prolificacy of others. The first prolific breed identified was the Finn Sheep. The Romanov was the next breed identified as being highly fertile. The Booroola Merino is the most recently discovered prolific breed. However, it differs from the Finn and Romanov. The Awassi is the most prevalent sheep breed in the Arab Countries. The Awassi sheep breed is common in most of the Middle East Countries including Saudi Arabia, Jordan, Iraq, Syria, Lebanon, and Palestine. It is an extremely hardy breed, well adapted over centuries of use to nomadic. Breeding systems Pure-breeding Pure-breeding is the mating of rams and ewes of the same breed or type. A purebred flock can be managed as a single flock because all ewes and rams are of the same breed. The goal of purebred sheep production is to provide superior genetics (seedstock) to the commercial sheep industry. Seedstock are marketed as rams and replacement ewes to other seedstock producers or to commercial sheep operations. Out-breeding Within pure-breeding, there are several types of mating systems. Out-breeding is the mating of animals of the same breed but which have no closer relationship than at least 4 to 6 generations. Outbreeding is the recommended breeding practice for most purebred sheep breeders. Inbreeding Inbreeding is a system of breeding in which closely related animals are mated. inbreeding is defined as the mating of animals more closely related than the average relationship within the breed or population concerned. The primary genetic consequence of inbreeding is to increase the frequency of pairing of similar genes. In general, inbreeding results in an overall lowering in performance: vigor, disease resistance, reproductive efficiency, and survivability. It also increases the frequency of abnormalities. For example, the spread of spider lamb disease in black-faced sheep is believed to be the consequence of inbreeding. Line breeding Line breeding is a system of breeding in which the degree of relationship is less intense than in inbreeding and is usually directed towards keeping the offspring related to some highly prized ancestor. Line breeding is a mild form of inbreeding. Crossbreeding Crossbreeding is the mating of rams and ewes of different breed compositions or types. Crossbreeding is used extensively in the commercial sheep industry and the majority of slaughter lambs are crossbred. Crossbreeding offers two distinct advantages: 1) heterosis; and 2) breed complementarity. Heterosis or hybrid vigor is the superiority of the crossbred offspring. Mathematically, heterosis is the difference in performance between the crossbred and the average performance of its purebred parents. There are effects of heterosis in the crossbred offspring, crossbred dam, and crossbred ram. In general, crossbred individuals tend to be more vigorous, more fertile and grow faster than purebreds. The second major advantage of crossbreeding lies in the ability to utilize breed complementarity. All breeds have strengths and weaknesses. No one breed excels in all relevant traits. Thus, production can be optimized when mating systems place breeds in roles that maximize their strengths and minimize their weaknesses. Sheep breeding Life cycle Ewes are pregnant for just under five months before they lamb, and may have anywhere from one to three lambs per birth. Twin and single lambs are most common, triplets less common. An ewe may lamb once or twice a year. Lambs are weaned at three months. Sheep are full grown at two years and can weigh between 60 and 125 kilograms. Sheep can live to eleven or twelve years of age. Animal breeding is a branch of animal science that addresses the evaluation of the genetic value of domestic livestock. A breed is a group of domestic animals with a homogeneous appearance, behavior, and other characteristics that distinguish it from other animals. Each is a distinct species and genus. Sheep (Ovis aries) have 54 chromosomes, while goats (Capra aegagrus hircus) have 60. While sheep and goats will occasionally mate, fertile sheep-goat hybrids are rare. Hybrids made in the laboratory are called chimeras. Chimeras. Physical differences Sheep and goats have numerous physical differences. Most goats have hair coats that do not require shearing or combing. Most sheep grow woolly coats that need to be sheared at least annually. Lamb tails are usually docked (shortened) whereas goat tails are not. Sheep have an upper lip that is divided by a distinct philtrum (groove). The goat does not. Male goats have glands beneath their tail. Sheep have face or tear glands beneath their eyes and foot or scent glands between the toes. Male goats develop a distinct odor as they grow in sexual maturity.