The wolf known as the grey/gray wolf or timber wolf, is a canine native to the wilderness and remote areas of Eurasia and North America. It is the largest extant member of its family, with males averaging 43 -- females 36 -- 38.5 kg. It is distinguished from other Canis species by its larger size and less pointed features on the ears and muzzle, its winter fur is long and bushy and predominantly a mottled gray in color, although nearly pure white and brown to black occur. Mammal Species of the World, a standard reference work in zoology, recognises 38 subspecies of C. lupus. The gray wolf is the second most specialized member of the genus Canis, after the Ethiopian wolf, as demonstrated by its morphological adaptations to hunting large prey, its more gregarious nature, its advanced expressive behavior, it is nonetheless related enough to smaller Canis species, such as the coyote, golden jackal, to produce fertile hybrids. It is the only species of Canis to have a range encompassing both Eurasia and North America, originated in Eurasia during the Pleistocene, colonizing North America on at least three separate occasions during the Rancholabrean.
It is a social animal, travelling in nuclear families consisting of a mated pair, accompanied by the pair's adult offspring. The gray wolf is an apex predator throughout its range, with only humans and tigers posing a serious threat to it, it feeds on large ungulates, though it eats smaller animals, livestock and garbage. A seven-year-old wolf is considered to be old, the maximum lifespan is about 16 years; the global gray wolf population is estimated to be 300,000. The gray wolf is one of the world's best-known and most-researched animals, with more books written about it than any other wildlife species, it has a long history of association with humans, having been despised and hunted in most pastoral communities because of its attacks on livestock, while conversely being respected in some agrarian and hunter-gatherer societies. Although the fear of wolves is pervasive in many human societies, the majority of recorded attacks on people have been attributed to animals suffering from rabies. Non-rabid wolves have attacked and killed people children, but this is rare, as wolves are few, live away from people, have developed a fear of humans from hunters and shepherds.
The English'wolf' stems from the Old English wulf, itself thought to be derived from the Proto-Germanic *wulfaz. The Latin lupus is a Sabine loanword. Both derive from the Proto-Indo-European root * lukwos; the species Canis lupus was first recorded by Carl Linnaeus in his publication Systema Naturae in 1758, with the Latin classification translating into the English words "dog wolf". The 37 subspecies of Canis lupus are listed under the designated common name of "wolf" in Mammal Species of the World, published in 2005; the nominate subspecies is the Eurasian wolf known as the common wolf. The subspecies includes the domestic dog, eastern wolf and red wolf, but lists C. l. italicus as a synonym of C. l. lupus. However, the classification of several as either species or subspecies has been challenged; the evolution of the wolf occurred over a geologic time scale of at least 300,000 years. The gray wolf Canis lupus is a adaptable species, able to exist in a range of environments and which possesses a wide distribution across the Holarctic.
Studies of modern gray wolves have identified distinct sub-populations that live in close proximity to each other. This variation in sub-populations is linked to differences in habitat – precipitation, temperature and prey specialization – which affect cranio-dental plasticity; the archaeological and paleontological records show gray wolf continuous presence for at least the last 300,000 years. This continuous presence contrasts with genomic analyses, which suggest that all modern wolves and dogs descend from a common ancestral wolf population that existed as as 20,000 years ago; these analyses indicate a population bottleneck, followed by a rapid radiation from an ancestral population at a time during, or just after, the Last Glacial Maximum. However, the geographic origin of this radiation is not known. In 2018, whole genome sequencing was used to compare members of the genus Canis, along with the dhole and the African hunting dog. There is evidence of gene flow between African golden wolves, golden jackals, gray wolves.
One African golden wolf from the Egyptian Sinai Peninsula showed high admixture with the Middle Eastern gray wolves and dogs, highlighting the role of the land bridge between the African and Eurasian continents in canid evolution. There was evidence of gene flow between golden jackals and Middle Eastern wolves, less so with European and Asian wolves, least with North American wolves; the study proposes that the golden jackal ancestry found in North American wolves may have occurred before the divergence of the Eurasian and North American gray wolves. The study indicates that the common ancestor of the coyote and gray wolf has genetically admixed with a ghost population of an extinct unidentified canid; the canid is genetically close to the dhole and has evolved after the divergence of the African hunting dog from the other canid species. The basal position of the coyote compared to the wolf is proposed to be due to the coyote retaining more of the mitochondrial genome of this unknown canid.
In 2013, a genetic study found that the wolf population in Europe was divided along a north-south axis and formed five major clusters. Three clusters were identified occupying southern and
Domestic sheep are quadrupedal, ruminant mammals kept as livestock. Like most ruminants, sheep are members of the even-toed ungulates. Although the name sheep applies to many species in the genus Ovis, in everyday usage it always refers to Ovis aries. Numbering a little over one billion, domestic sheep are the most numerous species of sheep. An adult female sheep is referred to as a ewe, an intact male as a ram or a tup, a castrated male as a wether, a younger sheep as a lamb. Sheep are most descended from the wild mouflon of Europe and Asia. One of the earliest animals to be domesticated for agricultural purposes, sheep are raised for fleeces and milk. A sheep's wool is the most used animal fiber, is harvested by shearing. Ovine meat is called lamb when from younger animals and mutton when from older ones in Commonwealth countries, lamb in the United States. Sheep continue to be important for wool and meat today, are occasionally raised for pelts, as dairy animals, or as model organisms for science.
Sheep husbandry is practised throughout the majority of the inhabited world, has been fundamental to many civilizations. In the modern era, New Zealand, the southern and central South American nations, the British Isles are most associated with sheep production. Sheepraising has a large lexicon of unique terms which vary 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 herd or mob. Many other specific terms for the various life stages of sheep exist related to lambing and age. Being a key animal in the history of farming, sheep have a entrenched place in human culture, find representation in much modern language and symbology; as livestock, sheep are most associated with pastoral, Arcadian imagery. Sheep figure in many mythologies—such as the Golden Fleece—and major religions the Abrahamic traditions. In both ancient and modern religious ritual, sheep are used as sacrificial animals; the exact line of descent between domestic sheep and their wild ancestors is unclear.
The most common hypothesis states. Sheep were among the first animals to be domesticated by humankind. C in Mesopotamia; the rearing of sheep for secondary products, the resulting breed development, began in either southwest Asia or western Europe. Sheep were kept for meat and skins. Archaeological evidence from statuary found at sites in Iran suggests that selection for woolly sheep may have begun around 6000 BC, the earliest woven wool garments have been dated to two to three thousand years later. Sheep husbandry spread in Europe. Excavations show that in about 6000 BC, during the Neolithic period of prehistory, the Castelnovien people, living around Châteauneuf-les-Martigues near present-day Marseille in the south of France, were among the first in Europe to keep domestic sheep. From its inception, ancient Greek civilization relied on sheep as primary livestock, were said to name individual animals. Ancient Romans kept sheep on a wide scale, were an important agent in the spread of sheep raising.
Pliny the Elder, in his Natural History, speaks at length about wool. European colonists spread the practice to the New World from 1493 onwards. Domestic sheep are small ruminants with a crimped hair called wool and with horns forming a lateral spiral. Domestic sheep 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, or horns in both sexes, or in males only. Most horned breeds have a single pair. Another trait unique to domestic sheep as compared to wild ovines is their wide variation in color. Wild sheep are variations of brown hues, variation within species is limited. Colors of domestic sheep range from pure white to dark chocolate brown, spotted or piebald. Selection for dyeable white fleeces began early in sheep domestication, as white wool is a dominant trait it spread quickly.
However, colored sheep do appear in many modern breeds, may 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 for handspinning; the nature of the fleece varies among the breeds, from dense and crimped, to long and hairlike. There is variation of wool type and quality among members of the same flock, so wool classing is a step in the commercial processing of the fibre. Depending on breed, sheep show a range of weights, their rate of growth and mature weight is a heritable trait, selected for in breeding. Ewes weigh between 45 and 100 kilograms, rams between 45 and 160 kilograms; when all deciduous teeth have erupted, the sheep has 20 teeth. Mature sheep have 32 teeth; 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 the rear
Kingdom of Castile
The Kingdom of Castile was a large and powerful state located on the Iberian Peninsula during the Middle Ages. Its name comes from the host of castles constructed in the region, it began in the 9th century as the County of Castile, an eastern frontier lordship of the Kingdom of León. During the 10th century its counts increased their autonomy, but it was not until 1065 that it was separated from León and became a kingdom in its own right. Between 1072 and 1157 it was again united with León, after 1230 this union became permanent. Throughout this period the Castilian kings made extensive conquests in southern Iberia at the expense of the Islamic principalities. Castile and León, with their southern acquisitions, came to be known collectively as the Crown of Castile, a term that came to encompass overseas expansion. According to the chronicles of Alfonso III of Asturias. In Al-Andalus chronicles from the Cordoban Caliphate, the oldest sources refer to it as Al-Qila, or "the castled" high plains past the territory of Alava, more south to it and the first encountered in their expeditions from Zaragoza.
The name reflects its origin as a march on the eastern frontier of the Kingdom of Asturias, protected by castles, towers or castra. The County of Castile, bordered in the south by the northern reaches of the Spanish Sistema Central mountain system, just north of modern-day Madrid province, it was re-populated by inhabitants of Cantabria, Asturias and Visigothic and Mozarab origins. It had customary laws. From the first half of the 9th century until the middle of the century, in which it came to be paid more closer attention to, its administration and defense by the monarchs of Leon – due the increased incursions from the Emirate of Córdoba – its first repopulation settlements were led by small abbots and local counts from the other side of the Cantabrian ridge neighbor valleys and Primorias and smaller ones, being its first settlers from the contiguous maritime valleys of Mena and Encartaciones in nearby Biscay, some of whom had abandoned those exposed areas of the Meseta a few decades earlier, taken refuge by the much dense and intractable woods of the Atlantic valleys, so they were not that foreign to them.
A mix of settlers from the Cantabrian and Basque coastal areas, which were swelled with refugees, was led under the protection of Abbot Vitulus and his brother, count Herwig, as registered in the local charters they signed around the first years of the 800's. The areas that they settled didn't extend far from the Cantabrian southeastern ridges, not beyond the southern reaches of the high Ebro river valleys and canyon gores; the first Count of a wider and more united Castile was Rodrigo in 850, under Ordoño I of Asturias and Alfonso III of Asturias, who settled and fortified the ancient Cantabrian hill town of Amaya, much farther west and south of the Ebro river to offer a more easy defense and command of the still functional Roman Empire main highway passing by, south of the Cantabrian ridge all the way to Leon, from the Muslim military expeditions. Subsequently, the region was subdivided, separate counts being named to Alava, Cerezo & Lantarón, a reduced Castile. In 931 the County was reunified by Count Fernán González, who rose in rebellion against the Kingdom of León, successor state to Asturias, achieved an autonomous status, allowing the county to be inherited by his family instead of being subject to appointment by the Leonese king.
The minority of Count García Sánchez led Castile to accept Sancho III of Navarre, married to the sister of Count García, as feudal overlord. García was assassinated in 1028 while in León to marry the princess Sancha, sister of Bermudo III of León. Sancho III, acting as feudal overlord, appointed his younger son Ferdinand as Count of Castile, marrying him to his uncle's intended bride, Sancha of León. Following Sancho's 1035 death, Castile returned to the nominal control of León, but Ferdinand, allying himself with his brother García Sánchez III of Navarre, began a war with his brother-in-law Vermudo. At the Battle of Tamarón Vermudo was killed. In right of his wife, Ferdinand assumed the royal title as king of León and Castile, for the first time associating the royal title with the rule of Castile; when Ferdinand I died in 1065, the territories were divided among his children. Sancho II became King of Castile, Alfonso VI, King of León and García, King of Galicia, while his daughters were given towns, Urraca and Elvira, Toro.
Sancho II allied himself with Alfonso VI of León and together they conquered divided Galicia. Sancho attacked Alfonso VI and invaded León with the help of El Cid, drove his brother into exile, thereby reuniting the three kingdoms. Urraca permitted the greater part of the Leonese army to take refuge in the town of Zamora. Sancho laid siege to the town, but the Castilian king was assassinated in 1072 by Bellido Dolfos, a Galician nobleman; the Castilian troops withdrew. As a result, Alfonso VI recovered all his original territory of León, now became the king of Castile and Galicia; this was the second union of León and Castile, although the two kingdoms remained distinct entities joined only in a personal union. The before Alfonso VI in Santa Gadea de Burgos regarding the innocence of Alfonso in the matter of the murder of his brother is well known. During the first years of the 12th century Alfonso VI only son Sancho died leaving only his daughter. Due to this Alfonso VI took a different approach to the rest of Europeans kingdoms, including France
A pen is an enclosure for holding animals such as livestock or pets that are unwanted inside the house. The term describes types of enclosures that may confine many animals. Construction and terminology vary depending on the region of the world, animal species to be confined, local materials used and tradition. Pen or penning as a verb refers to the act of confining animals in an enclosure. In Australia and New Zealand a pen is a small enclosure for livestock, part of a larger construction, e.g. calf pen, forcing pen in sheep or cattle yards, or a sweating pen or catching pen in a shearing shed. In Australia, a paddock may encompass a large, fenced grazing area of many acres, not to be confused with the American English use of paddock as interchangeable with corral or pen, describing smaller, confined areas. In British English, a sheep pen is called a folding, sheepfold or sheepcote. Modern shepherds more use terms such as closing or confinement pen for small sheep pens. Most structures today referred to.
In the United States, the term pen describes outdoor small enclosures for holding animals. These may be for encasing livestock or pets. Pens may be named by their purpose, such as a holding pen, used for short-term confinement. A pen for cattle may be called a corral, a term borrowed from the Spanish language. Groups of pens that are part of a larger complex may be called a stockyard, where a series of pens holds a large number of animals, or a feedlot, type of stockyard used to confine animals that are being fattened. A large pen for horses is called a corral. In some places an exhibition arena may be called a show pen. A small pen for horses is only known as a pen if it lacks any roof or shelter, otherwise it is called a stall and is part of a stable. A large fenced grazing area of many acres is, in some cases, rangeland. Primitive pens in South Africa are called kraal. For pets, specialized folding fencing referred to as an exercise pen, x-pen, or ex pen, is used to surround an area outdoors but not always, in which the animals can move around.
They are used for dogs, such as to give puppies or adult dogs more space than dog crates, but can be used for rabbits and other animals. Exercise pens are made of sturdy wire, but can be plastic or wood. Horses, during training, are exercised in a round pen, sometimes referred to as an exercise pen. Pinfold and pound are synonyms of animal pound Boô Kraal "Macquarie Dictionary, The", 2nd edition, 1991 Media related to Pens at Wikimedia Commons
Bears are carnivoran mammals of the family Ursidae. They are classified as doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout the Northern Hemisphere and in the Southern Hemisphere. Bears are found on the continents of North America, South America and Asia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, short tails. While the polar bear is carnivorous, the giant panda feeds entirely on bamboo, the remaining six species are omnivorous with varied diets. With the exception of courting individuals and mothers with their young, bears are solitary animals, they may have an excellent sense of smell. Despite their heavy build and awkward gait, they are adept runners and swimmers. Bears use shelters, such as logs, as their dens. Bears have been hunted since prehistoric times for their fur. With their powerful physical presence, they play a prominent role in the arts and other cultural aspects of various human societies.
In modern times, bears have come under pressure through encroachment on their habitats and illegal trade in bear parts, including the Asian bile bear market. The IUCN lists six bear species as vulnerable or endangered, least concern species, such as the brown bear, are at risk of extirpation in certain countries; the poaching and international trade of these most threatened populations are prohibited, but still ongoing. The English word "bear" comes from Old English bera and belongs to a family of names for the bear in Germanic languages, such as Swedish björn used as a first name; this form is conventionally said to be related to a Proto-Indo-European word for "brown", so that "bear" would mean "the brown one". However, Ringe notes that while this etymology is semantically plausible, a word meaning "brown" of this form cannot be found in Proto-Indo-European, he suggests instead that "bear" is from the Proto-Indo-European word *ǵʰwḗr- ~ *ǵʰwér "wild animal". This terminology for the animal originated as a taboo avoidance term: proto-Germanic tribes replaced their original word for bear—arkto—with this euphemistic expression out of fear that speaking the animal's true name might cause it to appear.
According to author Ralph Keyes, this is the oldest known euphemism. Bear taxon names such as Arctoidea and Helarctos come from the ancient Greek word ἄρκτος, meaning bear, as do the names "arctic" and "antarctic", from the constellation Ursa Major, the "Great Bear", prominent in the northern sky. Bear taxon names such as Ursidae and Ursus come from he-bear/she-bear; the female first name "Ursula" derived from a Christian saint's name, means "little she-bear". In Switzerland, the male first name "Urs" is popular, while the name of the canton and city of Bern is derived from Bär, German for bear; the Germanic name Bernard means "bear-brave", "bear-hardy", or "bold bear". The Old English name Beowulf is a kenning; the family Ursidae is one of nine families in the suborder Caniformia, or "doglike" carnivorans, within the order Carnivora. Bears' closest living relatives are the pinnipeds and musteloids. Modern bears comprise eight species in three subfamilies: Ailuropodinae and Ursinae. Nuclear chromosome analysis show that the karyotype of the six ursine bears is nearly identical, with each having 74 chromosomes, whereas the giant panda has 42 chromosomes and the spectacled bear 52.
These smaller numbers can be explained by the fusing of some chromosomes, the banding patterns on these match those of the ursine species, but differ from those of procyonids, which supports the inclusion of these two species in Ursidae rather than in Procyonidae, where they had been placed by some earlier authorities. The earliest members of Ursidae belong to the extinct subfamily Amphicynodontinae, including Parictis and the younger Allocyon, both from North America; these animals looked different from today's bears, being small and raccoon-like in overall appearance, with diets more similar to that of a badger. Parictis does not appear in Africa until the Miocene, it is unclear whether late-Eocene ursids were present in Eurasia, although faunal exchange across the Bering land bridge may have been possible during a major sea level low stand as early as the late Eocene and continuing into the early Oligocene. European genera morphologically similar to Allocyon, to the much younger American Kolponomos, are known from the Oligocene, including Amphicticeps and Amphicynodon.
There has been various morphological evidence linking amphicynodontines with pinnipeds, as both groups were semi-aquatic, otter-like mammals. In addition to the support of the pinniped–amphicynodontine clade, other morphological and some molecular evidence supports bears being the closet living relatives to pinnipeds; the raccoon-sized, dog-like Cephalogale is the oldest-known member of the subfamily Hemicyoninae, which first appeared during the middle Oligocene in Eurasia about 30 Mya
Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar and cottonwood. In the September 2006 issue of Science Magazine, the Joint Genome Institute announced that the western balsam poplar was the first tree whose full DNA code had been determined by DNA sequencing; the genus has a large genetic diversity, can grow from 15–50 m tall, with trunks up to 2.5 m in diameter. The bark on young trees is smooth, white to greenish or dark grey, has conspicuous lenticels; the shoots are stout, with the terminal bud present. The leaves are spirally arranged, vary in shape from triangular to circular or lobed, with a long petiole. Leaf size is variable on a single tree with small leaves on side shoots, large leaves on strong-growing lead shoots; the leaves turn bright gold to yellow before they fall during autumn. The flowers are dioecious and appear in early spring before the leaves.
They are borne in long, sessile or pedunculate catkins produced from buds formed in the axils of the leaves of the previous year. The flowers are each seated in a cup-shaped disk, borne on the base of a scale, itself attached to the rachis of the catkin; the scales are obovate and fringed, hairy or smooth, caducous. The male flowers are without calyx or corolla, comprise a group of four to 60 stamens inserted on a disk; the female flower has no calyx or corolla, comprises a single-celled ovary seated in a cup-shaped disk. The style is short, with two to four stigmata, variously lobed, numerous ovules. Pollination is by wind, with the female catkins lengthening between pollination and maturity; the fruit is a two- to four-valved dehiscent capsule, green to reddish-brown, mature in midsummer, containing numerous minute light brown seeds surrounded by tufts of long, white hairs which aid wind dispersal. Poplars of the cottonwood section are wetlands or riparian trees; the aspens are among the most important boreal broadleaf trees.
Poplars and aspens are important food plants for the larvae of a large number of Lepidoptera species. Pleurotus populinus, the aspen oyster mushroom, is found on dead wood of Populus trees in North America. Several species of Populus in the United Kingdom and other parts of Europe have experienced heavy dieback; the genus Populus has traditionally been divided into six sections on the basis of leaf and flower characters. Recent genetic studies have supported this, confirming some suspected reticulate evolution due to past hybridisation and introgression events between the groups; some species had differing relationships indicated by their nuclear DNA and chloroplast DNA sequences, a clear indication of hybrid origin. Hybridisation continues to be common in the genus, with several hybrids between species in different sections known. Populus section Populus – aspens and white poplar Populus adenopoda – Chinese aspen Populus alba – white poplar Populus × canescens – grey poplar Populus spp. X – Pacific albus Populus davidiana – Korean aspen Populus grandidentata – bigtooth aspen Populus sieboldii – Japanese aspen Populus tremula – aspen, common aspen, Eurasian aspen, European aspen, quaking aspen Populus tremuloides – quaking aspen or trembling aspen Populus section Aigeiros – black poplars, some of the cottonwoods Populus deltoides – eastern cottonwood Populus fremontii – Fremont cottonwood Populus nigra – black poplar, placed here by nuclear DNA.
Populus Populus × canadensis – hybrid black poplar Populus × inopina – hybrid black poplar Populus section Tacamahaca – balsam poplars Populus angustifolia – willow-leaved poplar or narrowleaf cottonwood Populus balsamifera – Balsam poplar Populus cathayana – Populus koreana J. Rehnder – Korean poplar Populus laurifolia – laurel-leaf poplar Populus maximowiczii A. Henry – Maximowicz' poplar, Japanese poplar Populus simonii – Simon's poplar Populus suaveolens Fischer – Mongolian poplar Populus szechuanica – Sichuan poplar, placed here by nuclear DNA. Aigeiros Populus trichocarpa – western balsam poplar or black cottonwood Populus tristis, placed here by nuclear DNA.
Domestic sheep reproduction
As with other mammals, domestic sheep reproduction occurs sexually. Their reproductive strategy is similar to other domestic herd animals. A flock of sheep is mated by a single ram, which has either been chosen by a farmer or has established dominance through physical contest with other rams. Most sheep have a breeding season in the autumn; as a result of the influence of humans in sheep breeding, ewes produce multiple lambs. This increase in the lamb births, both in number and birth weight, may cause problems in delivery and lamb survival, requiring the intervention of shepherds. Ewes reach sexual maturity at six to eight months of age, rams at four to six. Sheep are seasonally polyoestrus animals. Ewes enter into oestrus cycles about every 17 days, which last for 30 hours. In addition to emitting a scent, they indicate readiness through physical displays towards rams; the phenomenon of the freemartin, a female bovine, behaviorally masculine and lacks functioning ovaries, is associated with cattle, but does occur to some extent in sheep.
The instance of freemartins in sheep may be increasing in concert with the rise in twinning. The Flehmen response is exhibited by rams; the vomeronasal organ has receptors. The ram displays this by curling his lip. Without human intervention, rams may fight during the rut to determine which individuals may mate with ewes. Rams unfamiliar ones, will fight outside the breeding period to establish dominance. During the rut normally friendly rams may become aggressive towards humans due to increases in their hormone levels. Aggressive rams were sometimes blindfolded or hobbled. Today, those who keep rams prefer softer preventative measures, such as moving within a clear line to an exit, never turning their back on a ram, dousing with water or a diluted solution of bleach or vinegar to dissuade charges. Without ultrasound or other special tools, determining if a sheep is pregnant is difficult. Ewes only begin to visibly show a pregnancy about six weeks before giving birth, so shepherds rely on the assumption that a ram will impregnate all the ewes in a flock.
However, by fitting a ram with a chest harness called a marking harness that holds a special crayon, ewes that have been mounted are marked with a color. Dye may be directly applied to the ram's brisket; this measure is not used in flocks where wool is important, since the color of a raddle contaminates it. The crayon in the marking harness can be changed during the breeding cycle to allow for lambing date predictions for each ewe. After mating, sheep have a gestation period of around five months. Within a few days of the impending birth, ewes begin to behave differently, they may lie down and stand erratically, paw the ground, or otherwise act out of sync with normal flock patterns. An ewe's udder will fill out, her vulva will swell. Vaginal, uterine or anal prolapse may occur, in which case either stitching or a physical retainer can be used to hold the orifice in if the problem persists. Ewes that experience serious issues while lambing such as prolapse, will be discarded from the flock to avoid further complications in upcoming years.
In addition to natural insemination by rams, artificial insemination and embryo transfers have been used in sheep breeding programs for many years in Australia and New Zealand. These programs have become more commonplace in the United States during the 2000s as the number of veterinarians qualified to perform these types of procedures with proficiency have grown. However, ovine AI is a complicated procedure compared to other livestock. Unlike cattle or goats, which have straight cervices that can be vaginally inseminated, ewes have a curved cervix, more difficult to access. Additionally, breeders were until unable to control their ewe's estrus cycles; the ability to control the estrus cycle is much easier today because of products that safely assist in aligning heat cycles. Some examples of products are PG600, CIDRs, Estrumate and Folltropin V; these products contain progesterone which will bring on the induction of estrus in ewes during seasonal anestrus. Seasonal anestrus is when ewes do not have regular estrous cycles outside the natural breeding season.
Vaginal insemination of sheep only produced 40-60% success rates, was thus called a "shot in the dark". In the 1980s, Australian researchers developed a laparoscopic insemination procedure which, combined with the use of progestogen and pregnant mare's serum gonadotropin, yielded much higher success rates, has become the standard for artificial insemination of sheep in the 21st century. Semen collection is an integral component of this entire process. Once semen has been collected it can be used for insemination or frozen for use at a date. Fresh semen is recognized as the method of choice as it lives longer and yields higher conception rates. Frozen semen will work but it must be the highest quality of semen and the ewes must be inseminated twice in the same day; the marketing of ram semen is a major part of this industry. Producers owning prize winning rams have found this to be a good avenue to leverage the accolades of their most famous animals. During embryo transfer a minor s