The Domestic Sheep (Ovis aries)...
The Domestic Sheep (Ovis aries) is the most common species of the sheep genus.
As such it is a woolly ruminant quadruped which probably descends from the wild
mouflon of south-central and south-west Asia.
Sheep breeders refer to female sheep as ewes, intact males as rams, castrated
males as wethers, yearlings as hoggets, and younger sheep as lambs. Note the
adjective applying to sheep: ovine; and the collective terms for sheep: flock
and mob. The term herd is also occasionally used in this sense.
Many breeds of sheep occur, generally sub-classable as: woolclass, hair class
and sheepmeat breeds.
Farmers develop wool breeds for superior wool quantity and quality (fineness of
fibers), wool staple length and degree of crimp in the fiber. Major wool breeds
include Merino, Rambouillet, Romney and Lincoln.
Breeders of dual purpose wool class sheep concentrate on fast growth, multiple
births, ease of lambing and hardiness. Drysdale is a sheep bred specifically for
carpet wool. An easy-care sheep is the Coopworth that has long wool and good
lamb meat production qualities.
Breeds of meat sheep include Suffolk, Hampshire, Dorset, Columbia, and Texel.
One dual-use breed is the Corriedale. 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. The Finnish Landrace sheep
has a reputation for multiple births.
Hair class sheep are the original class of sheep in the world, developed for
meat and leather. They are prolific, highly disease and parasite resistant
generally. 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,
are those breeds such as St. Croix, Blackbellie Barbado, Mouflon, Santa Inez and
Royal White eg. that 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.
Domestic sheep (Ovis Aries) exist worldwide in association with humans. There are two subgenera and eight species of Ovis. Wild sheep are usually found in upland areas. Sheep are gregarious, sometimes gathering in herds of over 100 individuals. In some species, mature males stay apart from the females and the young for most of the year. In both the old and New World, the rut occurs mainly in the autumn and early winter, and births take place in the spring. Chromosomal and archeological evidence indicates that the domestic sheep is descended from a mouflon-like animal and that domestication occurred about 10,000 - 11,000 years ago in the eastern Mediterranean region. No wild sheep has a woolly coat comparable to that of domestic sheep. There are now more than 800 breeds of domestic sheep. Domestic sheep have adversely affected its wild relatives in many areas by competing with them for forage and spreading disease. Wild species have also declined through agricultural encroachment, other human habitat modifications, as well as by indiscriminate hunting.
Complete mitochondrial DNA (mtDNA) control regions (CR) were sequenced and analysed in order to investigate wild sheep taxonomy and the origin of domestic sheep (Ovis aries). The dataset for phylogenetic analyses includes 63 unique CR sequences from wild sheep of the mouflon (O. musimon, O. orientalis), urial (O. vignei), argali (O. ammon) and bighorn (O. canadensis) groups, and from domestic sheep of Asia, Europe and New Zealand. Domestic sheep occurred in two clearly separated branches with mouflon (O. musimon) mixed into one of the domestic sheep clusters. Genetic distances and molecular datings based on O. canadensis CR and mtDNA protein-coding sequences provide strong evidence for domestications from two mouflon subspecies. Other wild sheep sequences are in two additional well-separated branches. Ovis ammon collium and O. ammon nigrimontana are joined with a specimen from the transkaspian Ust-Urt plateau currently named O. vignei arkal. Ovis ammon ammon, O. ammon darwini and O. vignei bochariensis represent a separate clade and the earliest divergence from the mouflon group. Therefore, O. musimon, O. vignei bochariensis and Ust-Urt sheep are not members of a 'moufloniform' or O. orientalis species, but belong to different clades. Furthermore, Ust-Urt sheep could be a hybrid population or an O. ammon subspecies closely related to O. ammon nigrimontana.