A dairy is a business enterprise established for the harvesting or processing of animal milk – from cows or goats, but from buffaloes, horses, or camels – for human consumption. A dairy is located on a dedicated dairy farm or in a section of a multi-purpose farm, concerned with the harvesting of milk. Terminology differs between countries. For example, in the United States, an entire dairy farm is called a "dairy"; the building or farm area where milk is harvested from the cow is called a "milking parlor" or "parlor". Except in the case of smaller dairies, where cows are put on pasture, milked in "stanchion barns"; the farm area where milk is stored in bulk tanks is known as the farm's "milk house". Milk is hauled to a "dairy plant" = referred to as a "dairy" - where raw milk is further processed and prepared for commercial sale of dairy products. In New Zealand, farm areas for milk harvesting are called "milking parlours", are known as "milking sheds"; as in the United States, sometimes milking sheds are referred to by their type, such as "herring bone shed" or "pit parlour".
Parlour design has evolved from simple barns or sheds to large rotary structures in which the workflow is efficiently handled. In some countries those with small numbers of animals being milked, the farm may perform the functions of a dairy plant, processing their own milk into salable dairy products, such as butter, cheese, or yogurt; this on-site processing is a traditional method of producing specialist milk products, common in Europe. In the United States a dairy can be a place that processes and sells dairy products, or a room, building or establishment where milk is stored and processed into milk products, such as butter or cheese. In New Zealand English the singular use of the word dairy exclusively refers to a corner shop, or superette; this usage is historical. As an attributive, the word dairy refers to milk-based products and processes, the animals and workers involved in their production: for example dairy cattle, dairy goat. A dairy farm produces a dairy factory processes it into a variety of dairy products.
These establishments constitute a component of the food industry. Milk producing animals have been domesticated for thousands of years, they were part of the subsistence farming that nomads engaged in. As the community moved about the country, their animals accompanied them. Protecting and feeding the animals were a big part of the symbiotic relationship between the animals and the herders. In the more recent past, people in agricultural societies owned dairy animals that they milked for domestic and local consumption, a typical example of a cottage industry; the animals might serve multiple purposes. In this case the animals were milked by hand and the herd size was quite small, so that all of the animals could be milked in less than an hour—about 10 per milker; these tasks were performed by a dairyman. The word dairy harkens back to Middle English dayerie, from deye and further back to Old English dæge. With industrialisation and urbanisation, the supply of milk became a commercial industry, with specialised breeds of cattle being developed for dairy, as distinct from beef or draught animals.
More people were employed as milkers, but it soon turned to mechanisation with machines designed to do the milking. The milking and the processing took place close together in space and time: on a dairy farm. People milked the animals by hand. Hand-milking is accomplished by grasping the teats in the hand and expressing milk either by squeezing the fingers progressively, from the udder end to the tip, or by squeezing the teat between thumb and index finger moving the hand downward from udder towards the end of the teat; the action of the hand or fingers is designed to close off the milk duct at the udder end and, by the movement of the fingers, close the duct progressively to the tip to express the trapped milk. Each half or quarter of the udder is emptied one milk-duct capacity at a time; the stripping action is repeated. Both methods result in the milk, trapped in the milk duct being squirted out the end into a bucket, supported between the knees of the milker, who sits on a low stool. Traditionally the cow, or cows, would stand in the paddock while being milked.
Young stock, would have to be trained to remain still to be milked. In many countries, the cows milked. While most countries produce their own milk products, the structure of the dairy industry varies in different parts of the world. In major milk-producing countries most milk is distributed through whole sale markets. In Ireland and Australia, for example, farmers' co-operatives own many of the large-scale processors, while in the United States many farmers and processors do business through individual contracts. In the United States, the country's 196 farmers' cooperatives sold 86% of milk in the U. S. in 2002, with five cooperatives accounting for half that. This was down from 2,300 cooperatives in the 1940s. In developing countries, the past practice of farmers marketing milk in their own neighborhoods is changing rapidly. Notable
Wheat is a grass cultivated for its seed, a cereal grain, a worldwide staple food. The many species of wheat together make up the genus Triticum; the archaeological record suggests that wheat was first cultivated in the regions of the Fertile Crescent around 9600 BCE. Botanically, the wheat kernel is a type of fruit called a caryopsis. Wheat is grown on more land area than any other food crop. World trade in wheat is greater than for all other crops combined. In 2016, world production of wheat was 749 million tonnes, making it the second most-produced cereal after maize. Since 1960, world production of wheat and other grain crops has tripled and is expected to grow further through the middle of the 21st century. Global demand for wheat is increasing due to the unique viscoelastic and adhesive properties of gluten proteins, which facilitate the production of processed foods, whose consumption is increasing as a result of the worldwide industrialization process and the westernization of the diet.
Wheat is an important source of carbohydrates. Globally, it is the leading source of vegetal protein in human food, having a protein content of about 13%, high compared to other major cereals but low in protein quality for supplying essential amino acids; when eaten as the whole grain, wheat is a source of dietary fiber. In a small part of the general population, gluten – the major part of wheat protein – can trigger coeliac disease, noncoeliac gluten sensitivity, gluten ataxia, dermatitis herpetiformis. Cultivation and repeated harvesting and sowing of the grains of wild grasses led to the creation of domestic strains, as mutant forms of wheat were preferentially chosen by farmers. In domesticated wheat, grains are larger, the seeds remain attached to the ear by a toughened rachis during harvesting. In wild strains, a more fragile rachis allows the ear to shatter and disperse the spikelets. Selection for these traits by farmers might not have been deliberately intended, but have occurred because these traits made gathering the seeds easier.
As the traits that improve wheat as a food source involve the loss of the plant's natural seed dispersal mechanisms domesticated strains of wheat cannot survive in the wild. Cultivation of wheat began to spread beyond the Fertile Crescent after about 8000 BCE. Jared Diamond traces the spread of cultivated emmer wheat starting in the Fertile Crescent sometime before 8800 BCE. Archaeological analysis of wild emmer indicates that it was first cultivated in the southern Levant, with finds dating back as far as 9600 BCE. Genetic analysis of wild einkorn wheat suggests that it was first grown in the Karacadag Mountains in southeastern Turkey. Dated archeological remains of einkorn wheat in settlement sites near this region, including those at Abu Hureyra in Syria, suggest the domestication of einkorn near the Karacadag Mountain Range. With the anomalous exception of two grains from Iraq ed-Dubb, the earliest carbon-14 date for einkorn wheat remains at Abu Hureyra is 7800 to 7500 years BCE. Remains of harvested emmer from several sites near the Karacadag Range have been dated to between 8600 and 8400 BCE, that is, in the Neolithic period.
With the exception of Iraq ed-Dubb, the earliest carbon-14 dated remains of domesticated emmer wheat were found in the earliest levels of Tell Aswad, in the Damascus basin, near Mount Hermon in Syria. These remains were dated by Willem van Zeist and his assistant Johanna Bakker-Heeres to 8800 BCE, they concluded that the settlers of Tell Aswad did not develop this form of emmer themselves, but brought the domesticated grains with them from an as yet unidentified location elsewhere. The cultivation of emmer reached Greece and Indian subcontinent by 6500 BCE, Egypt shortly after 6000 BCE, Germany and Spain by 5000 BCE. "The early Egyptians were developers of bread and the use of the oven and developed baking into one of the first large-scale food production industries." By 3000 BCE, wheat had reached Scandinavia. A millennium it reached China; the oldest evidence for hexaploid wheat has been confirmed through DNA analysis of wheat seeds, dating to around 6400-6200 BCE, recovered from Çatalhöyük.
The first identifiable bread wheat with sufficient gluten for yeasted breads has been identified using DNA analysis in samples from a granary dating to 1350 BCE at Assiros in Macedonia. From Asia, wheat continued to spread across Europe. In the British Isles, wheat straw was used for roofing in the Bronze Age, was in common use until the late 19th century. Technological advances in soil preparation and seed placement at planting time, use of crop rotation and fertilizers to improve plant growth, advances in harvesting methods have all combined to promote wheat as a viable crop; when the use of seed drills replaced broadcasting sowing of seed in the 18th century, another great increase in productivity occurred. Yields of pure wheat per unit area increased as methods of crop rotation were applied to long cultivated land, the use of fertilizers became widespread. Improved agricultural husbandry has more included threshing machines and reaping machines, tractor-drawn cultivators and planters, better varieties.
Great expansion of wheat production occurred as new arable land was farmed in the Americas and Australia in the 19th and 20th centuries. Leaves emerge from the shoot apical meristem in a telescoping fashion until the transition to reprod
In soil science, Podzols are the typical soils of coniferous or boreal forests. They are the typical soils of eucalypt forests and heathlands in southern Australia. In Western Europe, Podzols develop on heathland, a construct of human interference through grazing and burning. In some British moorlands with Podzolic soils, Cambisols are preserved under Bronze Age barrows. Podzol means "under-ash", is derived from the Russian под + зола́; the term was introduced in 1875 by Vasily Dokuchaev. It refers to the common experience of Russian peasants of plowing up an apparent under-layer of ash during first plowing of a virgin soil of this type. Podzols are able to occur on any parent material but derive from either quartz-rich sands and sandstones or sedimentary debris from magmatic rocks, provided there is high precipitation. Most Podzols are poor soils for agriculture due to the sandy portion, resulting in a low level of moisture and nutrients; some are excessively drained. Others have shallow rooting poor drainage due to subsoil cementation.
A low pH further compounds aluminum toxicity. The best agricultural use of Podzols is for grazing, although well-drained loamy types can be productive for crops if lime and fertilizer are used; the E horizon, 4 to 8 centimetres thick, is low in Fe and Al oxides and humus. It is formed under moist and acidic conditions where the parent material, such as granite or sandstone, is rich in quartz, it is found under a layer of organic material in the process of decomposition, 5 to 10 centimetres thick. In the middle, there is a thin horizon of 0.5 to 1 centimetre. The bleached soil horizon goes over into a red-brown horizon; the colour is strongest in the upper part, change at a depth of 50 to 100 centimetres progressively to the part of the soil, not affected by processes. The soil profiles are designated by the letters A, E, B and C. In some Podzols, the E horizon is absent—either masked by biological activity or obliterated by disturbance. Podzols with little or no E horizon development are classified as brown Podzolic soils called Umbrisols or Umbrepts.
Podzols cover about 4,850,000 square kilometres worldwide and are found under sclerophyllous woody vegetation. By extent Podzols are most common in temperate and boreal zones of the northern hemisphere but they can be found in other settings including both temperate rainforests and tropical areas. In South America Podzols occur beneath Nothofagus betuloides forests in Tierra del Fuego. Podzolization is complex soil formation process by which dissolved organic matter and ions of iron and aluminium, released through weathering of various minerals, form organo-mineral complexes and are moved from the upper parts of the soil profile and deposit in the deeper parts of soil. Through this process, the eluvial horizon becomes bleached and of ash-grey colour; the complexes move with percolating water further down to illuviated horizons which are coloured brown, red or black as they accumulate and consist of cemented sesquioxides and/or organic compounds. The podzolization is a typical soil formation process in Podzols.
Podzolization occurs under forest or heath vegetation and is common in cool and humid climates as these climates inhibit the activity of soil microbes in the topsoil. Overall, podzolization happens where the decomposition of organic matter is inhibited and as a result, acidic organic surface layers build up. Under these acidic conditions, nutrient deficiency further hampers the microbial degradation of organic complexing agents. Medium to coarse textured soils with base-poor parent material promote podzolization, as they encourage percolating water flow; the soil-forming process of podzolization can be broken down into two main steps: Mobilization and translocation of organic matter, Fe and Al from the surface horizon, Immobilization and stabilization of organic matter, Fe and Al into the subsoil. In the topsoil of acidic soils, organic matter together with Al- and Fe-ions, form organo-mineral complexes; these soluble chelates relocate with percolating water from the A to the B-horizon. As a result of this, the E horizon is left bleached and ash-grey in colour, while the B horizon becomes enriched with relocated organo-mineral complexes.
The colour of B horizon is red, brown or black, depending on the dominance of metal ions or organic matter. The boundary between the B and eluvial Ae horizon is distinct, sometimes a hardpan can form, as the relocated Fe and Al and organic matter increase mineral particles, cementing them into this compacted layer. There are several reasons why these organo-mineral complexes immobilize in the B horizon: If during the eluviation process more Al- or Fe-ions bind to the organic compounds, the complex can flocculate as the solubility of it decreases with increasing metal to carbon ratio. Apart from that, a higher pH in the lower soil horizons can result in the breakdown of metal-humus complexes. In the lower soil layers, the organic complexing agents can be degraded by functio
The soybean, or soya bean, is a species of legume native to East Asia grown for its edible bean, which has numerous uses. Fat-free soybean meal is a significant and cheap source of protein for animal feeds and many packaged meals. For example, soybean products, such as textured vegetable protein, are ingredients in many meat and dairy substitutes; the beans contain significant amounts of dietary minerals and B vitamins. Soy vegetable oil, used in food and industrial applications, is another product of processing the soybean crop. Traditional unfermented food uses of soybeans include soy milk, from which tofu and tofu skin are made. Fermented soy foods include soy sauce, fermented bean paste and tempeh. "Soy" originated as a corruption of the Japanese names for soy sauce. The etymology of the genus, comes from Linnaeus; when naming the genus, Linnaeus observed that one of the species within the species had a sweet root. Based on the sweetness, the Greek word for sweet, glykós, was Latinized; the genus name is not related to the amino acid glycine.
The genus Glycine Willd. is divided into two subgenera and Soja. The subgenus Soja F. J. Herm. Includes the cultivated soybean, Glycine max Merr. and the wild soybean, Glycine soja Sieb. & Zucc. Both species are annuals. Glycine soja is the wild ancestor of Glycine max, grows wild in China, Japan and Russia; the subgenus Glycine consists of at least 25 wild perennial species: for example, Glycine canescens F. J. Herm. and G. tomentella Hayata, both found in Australia and Papua New Guinea. Perennial soybean is now a widespread pasture crop in the tropics. Like some other crops of long domestication, the relationship of the modern soybean to wild-growing species can no longer be traced with any degree of certainty, it is a cultural variety with a large number of cultivars. Like most plants, soybeans grow in distinct morphological stages as they develop from seeds into mature plants; the first stage of growth is germination, a method which first becomes apparent as a seed's radicle emerges. This is the first stage of root growth and occurs within the first 48 hours under ideal growing conditions.
The first photosynthetic structures, the cotyledons, develop from the hypocotyl, the first plant structure to emerge from the soil. These cotyledons both act as leaves and as a source of nutrients for the immature plant, providing the seedling nutrition for its first 7 to 10 days; the first true leaves develop as a pair of single blades. Subsequent to this first pair, mature nodes form compound leaves with three blades. Mature trifoliolate leaves, having three to four leaflets per leaf, are between 6–15 cm long and 2–7 cm broad. Under ideal conditions, stem growth continues. Before flowering, roots can grow 1.9 cm per day. If rhizobia are present, root nodulation begins by the time. Nodulation continues for 8 weeks before the symbiotic infection process stabilizes; the final characteristics of a soybean plant are variable, with factors such as genetics, soil quality, climate affecting its form. Flowering is triggered by day length beginning once days become shorter than 12.8 hours. This trait is variable however, with different varieties reacting differently to changing day length.
Soybeans form inconspicuous, self-fertile flowers which are borne in the axil of the leaf and are white, pink or purple. Depending of the soybean variety, node growth may cease. Strains that continue nodal development after flowering are termed "indeterminates" and are best suited to climates with longer growing seasons. Soybeans drop their leaves before the seeds are mature; the fruit is a hairy pod that grows in clusters of three to five, each pod is 3–8 cm long and contains two to four seeds 5–11 mm in diameter. Soybean seeds come in a wide variety sizes and hull colors such as black, brown and green. Variegated and bicolored seed coats are common; the hull of the mature bean is hard, water-resistant, protects the cotyledon and hypocotyl from damage. If the seed coat is cracked, the seed will not germinate; the scar, visible on the seed coat, is called the hilum and at one end of the hilum is the micropyle, or small opening in the seed coat which can allow the absorption of water for sprouting.
Some seeds such as soybeans containing high levels of protein can undergo desiccation, yet survive and revive after water absorption. A. Carl Leopold began studying this capability at the Boyce Thompson Institute for Plant Research at Cornell University in the mid-1980s, he found soybeans and corn to have a range of soluble carbohydrates protecting the seed's cell viability. Patents were awarded to him in the early 1990s on techniques for protecting biological membranes and proteins in the dry state. Like many legumes, soybeans can fix atmospheric nitrogen, thanks to symbiotic bacteria from the Rhizobia group. Together and soybean oil content account for 56% of dry soybeans by weight; the remainder consists of 9 % water and 5 % ash. Soybeans comprise 8% seed coat or hull, 90% cotyledons and 2% hypocotyl axis or germ. 100 grams of raw soybeans supply 446 calories and are 9% water, 30% carbohydrates, 20% total fat and 36% p
In political and social sciences, communism is the philosophical, social and economic ideology and movement whose ultimate goal is the establishment of the communist society, a socioeconomic order structured upon the common ownership of the means of production and the absence of social classes and the state. Communism includes a variety of schools of thought, which broadly include Marxism and anarchism, as well as the political ideologies grouped around both. All of these share the analysis that the current order of society stems from its economic system, capitalism; the two classes are the working class—who must work to survive and who make up the majority within society—and the capitalist class—a minority who derives profit from employing the working class through private ownership of the means of production. The revolution will put the working class in power and in turn establish social ownership of the means of production, which according to this analysis is the primary element in the transformation of society towards communism.
Critics of communism can be divided into those concerning themselves with the practical aspects of 20th century communist states and those concerning themselves with communist principles and theory. Marxism-Leninism and democratic socialism were the two dominant forms of socialism in the 20th century; the term "communism" was first coined and defined in its modern definition by the French philosopher and writer Victor d'Hupay. In his 1777 book Projet de communauté philosophe, d'Hupay pushes the philosophy of the Enlightenment to principles which he lived up to during most of his life in his bastide of Fuveau; this book can be seen as the cornerstone of communist philosophy as d'Hupay defines this lifestyle as a "commune" and advises to "share all economic and material products between inhabitants of the commune, so that all may benefit from everybody's work". According to Richard Pipes, the idea of a classless, egalitarian society first emerged in Ancient Greece; the 5th-century Mazdak movement in Persia has been described as "communistic" for challenging the enormous privileges of the noble classes and the clergy, for criticizing the institution of private property and for striving to create an egalitarian society.
At one time or another, various small communist communities existed under the inspiration of Scripture. For example, in the medieval Christian Church some monastic communities and religious orders shared their land and their other property. Communist thought has been traced back to the works of the 16th-century English writer Thomas More. In his treatise Utopia, More portrayed a society based on common ownership of property, whose rulers administered it through the application of reason. In the 17th century, communist thought surfaced again in England, where a Puritan religious group known as the "Diggers" advocated the abolition of private ownership of land. In his 1895 Cromwell and Communism, Eduard Bernstein argued that several groups during the English Civil War espoused clear communistic, agrarian ideals and that Oliver Cromwell's attitude towards these groups was at best ambivalent and hostile. Criticism of the idea of private property continued into the Age of Enlightenment of the 18th century through such thinkers as Jean Jacques Rousseau in France.
Following the upheaval of the French Revolution communism emerged as a political doctrine. In the early 19th century, various social reformers founded communities based on common ownership. However, unlike many previous communist communities they replaced the religious emphasis with a rational and philanthropic basis. Notable among them were Robert Owen, who founded New Harmony in Indiana, as well as Charles Fourier, whose followers organized other settlements in the United States such as Brook Farm. In its modern form, communism grew out of the socialist movement in 19th-century Europe; as the Industrial Revolution advanced, socialist critics blamed capitalism for the misery of the proletariat—a new class of urban factory workers who labored under often-hazardous conditions. Foremost among these critics were his associate Friedrich Engels. In 1848, Marx and Engels offered a new definition of communism and popularized the term in their famous pamphlet The Communist Manifesto; the 1917 October Revolution in Russia set the conditions for the rise to state power of Vladimir Lenin's Bolsheviks, the first time any avowedly communist party reached that position.
The revolution transferred power to the All-Russian Congress of Soviets, in which the Bolsheviks had a majority. The event generated a great deal of theoretical debate within the Marxist movement. Marx predicted that socialism and communism would be built upon foundations laid by the most advanced capitalist development. However, Russia was one of the poorest countries in Europe with an enormous illiterate peasantry and a minority of industrial workers. Marx had explicitly stated; the moderate Mensheviks opposed Lenin's Bolshevik plan for socialist revolution before capitalism was more developed. The Bolsheviks' successful rise to power was based upon the slogans such as "Peace and land" which tapp
The reindeer known as the caribou in North America, is a species of deer with circumpolar distribution, native to Arctic, sub-Arctic, tundra and mountainous regions of northern Europe and North America. This includes both migratory populations. Rangifer herd size varies in different geographic regions; the Taimyr herd of migrating Siberian tundra reindeer in Russia is the largest wild reindeer herd in the world, varying between 400,000 and 1,000,000. What was once the second largest herd is the migratory boreal woodland caribou George River herd in Canada, with former variations between 28,000 and 385,000; as of January 2018, there are fewer than 9,000 animals estimated to be left in the George River herd, as reported by the Canadian Broadcasting Corporation. The New York Times reported in April 2018 of the disappearance of the only herd of southern mountain caribou in the lower 48 states, with an expert calling it "functionally extinct" after the herd's size dwindled to a mere three animals.
Rangifer varies in size and colour from the smallest, the Svalbard reindeer, to the largest, the boreal woodland caribou. The North American range of caribou extends from Alaska through Yukon, the Northwest Territories and Nunavut into the boreal forest and south through the Canadian Rockies and the Columbia and Selkirk Mountains; the Barren-ground caribou, Porcupine caribou, Peary caribou live in the tundra, while the shy boreal woodland caribou prefer the boreal forest. The Porcupine caribou and the barren-ground caribou form large herds and undertake lengthy seasonal migrations from birthing grounds to summer and winter feeding grounds in the tundra and taiga; the migrations of Porcupine caribou herds are among the longest of any mammal. Barren-ground caribou are found in Kitaa in Greenland, but the larger herds are in Alaska, the Northwest Territories, Nunavut; some subspecies are rare and at least one has become extinct: the Queen Charlotte Islands caribou of Canada. The range of the sedentary boreal woodland caribou covered more than half of Canada and into the northern States in the U.
S. Woodland caribou have disappeared from most of their original southern range and were designated as threatened in 2002 by the Committee on the Status of Endangered Wildlife in Canada. Environment Canada reported in 2011 that there were 34,000 boreal woodland caribou in 51 ranges remaining in Canada.. Siberian tundra reindeer herds are in decline, Rangifer tarandus is considered to be vulnerable by the IUCN. Arctic peoples have depended on caribou for food and shelter, such as the Caribou Inuit, the inland-dwelling Inuit of the Kivalliq Region in northern Canada, the Caribou Clan in Yukon, the Inupiat, the Inuvialuit, the Hän, the Northern Tutchone, the Gwich'in. Hunting wild reindeer and herding of semi-domesticated reindeer are important to several Arctic and sub-Arctic peoples such as the Duhalar for meat, antlers and transportation; the Sami people have depended on reindeer herding and fishing for centuries. In Lapland, reindeer pull pulks. Male and female reindeer can grow antlers annually, although the proportion of females that grow antlers varies between population and season.
Antlers are larger on males. In traditional festive legend, Santa Claus's reindeer pull a sleigh through the night sky to help Santa Claus deliver gifts to good children on Christmas Eve. Carl Linnaeus chose the name Rangifer for the reindeer genus, which Albertus Magnus used in his De animalibus, fol. Liber 22, Cap. 268: "Dicitur Rangyfer quasi ramifer". This word may go back to the Saami word raingo. Linnaeus chose the word tarandus as the specific epithet, making reference to Ulisse Aldrovandi's Quadrupedum omnium bisulcorum historia fol. 859–863, Cap. 30: De Tarando. However and Konrad Gesner – thought that rangifer and tarandus were two separate animals. In any case, the tarandos name goes back to Theophrastus; the use of the terms Reindeer and caribou for the same animal can cause confusion, but the IUCN delineates the issue: "The world's Caribou and Reindeer are classified as a single species Rangifer tarandus. Reindeer is the European name for the species while in North America, the species is known as Caribou."
The word rein is of Norse origin. The word deer was broader in meaning, but became more specific over time. In Middle English, der meant a wild animal of any kind, in contrast to cattle; the word caribou comes through French, from the Mi'kmaq qalipu, meaning "snow shoveler", referring to its habit of pawing through the snow for food. Because of its importance to many cultures, Rangifer tarandus and some of its subspecies have names in many languages. Inuktitut is spoken in the eastern Arctic, the caribou is known by the name tuktu; the Gwich’in people have over two dozen distinct caribou-related words. The species' taxonomic name, Rangifer tarandus, was defined by Carl Linnaeus in 1758; the woodland caribou subspecies' taxonomic name Rangifer tarandus caribou was defined by Gmelin in 1788. Based on Banfield's often-cited A Revision of the Reindeer and Caribou, Genus Rangifer, R. t. caboti, R. t. osborni and R. t. terraenovae were considered invalid and included in R. t. caribou. Some recent authorities have considered them all valid suggesting that they are quite distinct.
In their book entitled Mammal Species of the World, American zoologist Don E. Wilson and DeeAnn Reeder agree with Valerius Geist, specialist on large North American mammals, that
The horse is one of two extant subspecies of Equus ferus. It is an odd-toed ungulate mammal belonging to the taxonomic family Equidae; the horse has evolved over the past 45 to 55 million years from a small multi-toed creature, into the large, single-toed animal of today. Humans began domesticating horses around 4000 BC, their domestication is believed to have been widespread by 3000 BC. Horses in the subspecies caballus are domesticated, although some domesticated populations live in the wild as feral horses; these feral populations are not true wild horses, as this term is used to describe horses that have never been domesticated, such as the endangered Przewalski's horse, a separate subspecies, the only remaining true wild horse. There is an extensive, specialized vocabulary used to describe equine-related concepts, covering everything from anatomy to life stages, colors, breeds and behavior. Horses' anatomy enables them to make use of speed to escape predators and they have a well-developed sense of balance and a strong fight-or-flight response.
Related to this need to flee from predators in the wild is an unusual trait: horses are able to sleep both standing up and lying down, with younger horses tending to sleep more than adults. Female horses, called mares, carry their young for 11 months, a young horse, called a foal, can stand and run shortly following birth. Most domesticated horses begin training in harness between the ages of two and four, they reach full adult development by age five, have an average lifespan of between 25 and 30 years. Horse breeds are loosely divided into three categories based on general temperament: spirited "hot bloods" with speed and endurance. There are more than 300 breeds of horse in the world today, developed for many different uses. Horses and humans interact in a wide variety of sport competitions and non-competitive recreational pursuits, as well as in working activities such as police work, agriculture and therapy. Horses were used in warfare, from which a wide variety of riding and driving techniques developed, using many different styles of equipment and methods of control.
Many products are derived from horses, including meat, hide, hair and pharmaceuticals extracted from the urine of pregnant mares. Humans provide domesticated horses with food and shelter, as well as attention from specialists such as veterinarians and farriers. Specific terms and specialized language are used to describe equine anatomy, different life stages and breeds. Depending on breed and environment, the modern domestic horse has a life expectancy of 25 to 30 years. Uncommonly, a few animals live into their 40s and beyond; the oldest verifiable record was "Old Billy", a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, listed in Guinness World Records as the world's oldest living pony, died in 2007 at age 56. Regardless of a horse or pony's actual birth date, for most competition purposes a year is added to its age each January 1 of each year in the Northern Hemisphere and each August 1 in the Southern Hemisphere; the exception is in endurance riding, where the minimum age to compete is based on the animal's actual calendar age.
The following terminology is used to describe horses of various ages: Foal: A foal of either sex less than one year old. A nursing foal is sometimes called a suckling and a foal, weaned is called a weanling. Most domesticated foals are weaned at five to seven months of age, although foals can be weaned at four months with no adverse physical effects. Yearling: A horse of either sex, between one and two years old. Colt: A male horse under the age of four. A common terminology error is to call any young horse a "colt", when the term only refers to young male horses. Filly: A female horse under the age of four. Mare: A female horse four years old and older. Stallion: A non-castrated male horse four years old and older; the term "horse" is sometimes used colloquially to refer to a stallion. Gelding: A castrated male horse of any age. In horse racing, these definitions may differ: For example, in the British Isles, Thoroughbred horse racing defines colts and fillies as less than five years old. However, Australian Thoroughbred racing defines fillies as less than four years old.
The height of horses is measured at the highest point of the withers. This point is used because it is a stable point of the anatomy, unlike the head or neck, which move up and down in relation to the body of the horse. In English-speaking countries, the height of horses is stated in units of hands and inches: one hand is equal to 4 inches; the height is expressed as the number of full hands, followed by a point the number of additional inches, ending with the abbreviation "h" or "hh". Thus, a horse described; the size of horses varies by breed, but is influenced by nutrition. Light riding horses range in height from 14 to 16 hands and can weigh from 380 to 550 kilograms. Larger riding horses start at about 15.2 hands and are as tall as 17 hands, weighing from 500 to 600 kilograms. Heavy or draft horses are at least 16 hands (64 inches, 16