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Saturday, September 4, 2021

Behavioral modernity

From Wikipedia, the free encyclopedia
 
Upper Paleolithic (16,000-year-old) cave painting from Lascaux cave in France

Behavioral modernity is a suite of behavioral and cognitive traits that distinguishes current Homo sapiens from other anatomically modern humans, hominins, and primates. Most scholars agree that modern human behavior can be characterized by abstract thinking, planning depth, symbolic behavior (e.g., art, ornamentation), music and dance, exploitation of large game, and blade technology, among others. Underlying these behaviors and technological innovations are cognitive and cultural foundations that have been documented experimentally and ethnographically by evolutionary and cultural anthropologists. These human universal patterns include cumulative cultural adaptation, social norms, language, and extensive help and cooperation beyond close kin.

Within the tradition of evolutionary anthropology and related disciplines, it has been argued that the development of these modern behavioral traits, in combination with the climatic conditions of the Last Glacial Period and Last Glacial Maximum causing population bottlenecks, contributed to the evolutionary success of Homo sapiens worldwide relative to Neanderthals, Denisovans, and other archaic humans.

Arising from differences in the archaeological record, debate continues as to whether anatomically modern humans were behaviorally modern as well. There are many theories on the evolution of behavioral modernity. These generally fall into two camps: gradualist and cognitive approaches. The Later Upper Paleolithic Model theorises that modern human behavior arose through cognitive, genetic changes in Africa abruptly around 40,000–50,000 years ago around the time of the Out-of-Africa migration, prompting the movement of modern humans out of Africa and across the world. Other models focus on how modern human behavior may have arisen through gradual steps, with the archaeological signatures of such behavior appearing only through demographic or subsistence-based changes. Many cite evidence of behavioral modernity earlier (by at least about 150,000–75,000 years ago and possibly earlier) namely in the African Middle Stone Age. Sally McBrearty and Alison S. Brooks are notable proponents of gradualism, challenging European-centric models by situating more change in the Middle Stone Age of African pre-history, though this version of the story is more difficult to develop in concrete terms due to a thinning fossil record as one goes further back in time.

Definition

To classify what should be included in modern human behavior, it is necessary to define behaviors that are universal among living human groups. Some examples of these human universals are abstract thought, planning, trade, cooperative labor, body decoration, and the control and use of fire. Along with these traits, humans possess much reliance on social learning. This cumulative cultural change or cultural "ratchet" separates human culture from social learning in animals. As well, a reliance on social learning may be responsible in part for humans' rapid adaptation to many environments outside of Africa. Since cultural universals are found in all cultures including some of the most isolated indigenous groups, these traits must have evolved or have been invented in Africa prior to the exodus.

Archaeologically, a number of empirical traits have been used as indicators of modern human behavior. While these are often debated a few are generally agreed upon. Archaeological evidence of behavioral modernity includes:

Critiques

Several critiques have been placed against the traditional concept of behavioral modernity, both methodologically and philosophically. Shea (2011) outlines a variety of problems with this concept, arguing instead for "behavioral variability", which, according to the author, better describes the archaeological record. The use of trait lists, according to Shea (2011), runs the risk of taphonomic bias, where some sites may yield more artifacts than others despite similar populations; as well, trait lists can be ambiguous in how behaviors may be empirically recognized in the archaeological record. Shea (2011) in particular cautions that population pressure, cultural change, or optimality models, like those in human behavioral ecology, might better predict changes in tool types or subsistence strategies than a change from "archaic" to "modern" behavior. Some researchers argue that a greater emphasis should be placed on identifying only those artifacts which are unquestionably, or purely, symbolic as a metric for modern human behavior.

Theories and models

Late Upper Paleolithic Model or "Upper Paleolithic Revolution"

The Late Upper Paleolithic Model, or Upper Paleolithic Revolution, refers to the idea that, though anatomically modern humans first appear around 150,000 years ago (as was once believed), they were not cognitively or behaviorally "modern" until around 50,000 years ago, leading to their expansion out of Africa and into Europe and Asia. These authors note that traits used as a metric for behavioral modernity do not appear as a package until around 40–50,000 years ago. Klein (1995) specifically describes evidence of fishing, bone shaped as a tool, hearths, significant artifact diversity, and elaborate graves are all absent before this point. According to these authors, art only becomes common beyond this switching point, signifying a change from archaic to modern humans. Most researchers argue that a neurological or genetic change, perhaps one enabling complex language, such as FOXP2, caused this revolutionary change in humans.

Alternative models

Contrasted with this view of a spontaneous leap in cognition among ancient humans, some authors like Alison S. Brooks, primarily working in African archaeology, point to the gradual accumulation of "modern" behaviors, starting well before the 50,000 year benchmark of the Upper Paleolithic Revolution models. Howiesons Poort, Blombos, and other South African archaeological sites, for example, show evidence of marine resource acquisition, trade, the making of bone tools, blade and microlith technology, and abstract ornamentation at least by 80,000 years ago. Given evidence from Africa and the Middle East, a variety of hypotheses have been put forth to describe an earlier, gradual transition from simple to more complex human behavior. Some authors have pushed back the appearance of fully modern behavior to around 80,000 years ago or earlier in order to incorporate the South African data.

Others focus on the slow accumulation of different technologies and behaviors across time. These researchers describe how anatomically modern humans could have been cognitively the same and what we define as behavioral modernity is just the result of thousands of years of cultural adaptation and learning. D'Errico and others have looked at Neanderthal culture, rather than early human behavior exclusively, for clues into behavioral modernity. Noting that Neanderthal assemblages often portray traits similar to those listed for modern human behavior, researchers stress that the foundations for behavioral modernity may in fact lie deeper in our hominin ancestors. If both modern humans and Neanderthals express abstract art and complex tools then "modern human behavior" cannot be a derived trait for our species. They argue that the original "human revolution" theory reflects a profound Eurocentric bias. Recent archaeological evidence, they argue, proves that humans evolving in Africa some 300,000 or even 400,000 years ago were already becoming cognitively and behaviourally "modern". These features include blade and microlithic technology, bone tools, increased geographic range, specialized hunting, the use of aquatic resources, long distance trade, systematic processing and use of pigment, and art and decoration. These items do not occur suddenly together as predicted by the "human revolution" model, but at sites that are widely separated in space and time. This suggests a gradual assembling of the package of modern human behaviours in Africa, and its later export to other regions of the Old World.

Between these extremes is the view – currently supported by archaeologists Chris Henshilwood, Curtis Marean, Ian Watts and others – that there was indeed some kind of 'human revolution' but that it occurred in Africa and spanned tens of thousands of years. The term "revolution" in this context would mean not a sudden mutation but a historical development along the lines of "the industrial revolution" or "the Neolithic revolution". In other words, it was a relatively accelerated process, too rapid for ordinary Darwinian "descent with modification" yet too gradual to be attributed to a single genetic or other sudden event. These archaeologists point in particular to the relatively explosive emergence of ochre crayons and shell necklaces apparently used for cosmetic purposes. These archaeologists see symbolic organisation of human social life as the key transition in modern human evolution. Recently discovered at sites such as Blombos Cave and Pinnacle Point, South Africa, pierced shells, pigments and other striking signs of personal ornamentation have been dated within a time-window of 70,000–160,000 years ago in the African Middle Stone Age, suggesting that the emergence of Homo sapiens coincided, after all, with the transition to modern cognition and behaviour. While viewing the emergence of language as a 'revolutionary' development, this school of thought generally attributes it to cumulative social, cognitive and cultural evolutionary processes as opposed to a single genetic mutation.

A further view, taken by archaeologists such as Francesco D'Errico and João Zilhão, is a multi-species perspective arguing that evidence for symbolic culture in the form of utilised pigments and pierced shells are also found in Neanderthal sites, independently of any "modern" human influence.

Cultural evolutionary models may also shed light on why although evidence of behavioral modernity exists before 50,000 years ago it is not expressed consistently until that point. With small population sizes, human groups would have been affected by demographic and cultural evolutionary forces that may not have allowed for complex cultural traits. According to some authors until population density became significantly high, complex traits could not have been maintained effectively. Some genetic evidence supports a dramatic increase in population size before human migration out of Africa. High local extinction rates within a population also can significantly decrease the amount of diversity in neutral cultural traits, regardless of cognitive ability.

Highly speculatively, bicameral mind theory argues for an additional, and cultural rather than genetic, shift from selfless to self-perceiving forms of human cognition and behavior very late in human history, in the Bronze Age. This is based on a literary analysis of Bronze Age texts which claims to show the first appearances of the concept of self around this time, replacing the voices of gods as the primary form of recorded human cognition. This non-mainstream theory is not widely accepted but does receive serious academic interest from time to time.

Archaeological evidence

Africa

Recent research indicates that Homo sapiens originated in Africa between around 350,000 and 260,000 years ago. There is some evidence for the beginning of modern behavior among early African H. sapiens around that period.

Before the Out of Africa theory was generally accepted, there was no consensus on where the human species evolved and, consequently, where modern human behavior arose. Now, however, African archaeology has become extremely important in discovering the origins of humanity. The first Cro-Magnon expansion into Europe around 48,000 years ago is generally accepted as already "modern", and it is now generally believed that behavioral modernity appeared in Africa before 50,000 years ago, either significantly earlier, or possibly as a late Upper Paleolithic "revolution" soon before which prompted migration out of Africa.

A variety of evidence of abstract imagery, widened subsistence strategies, and other "modern" behaviors have been discovered in Africa, especially South, North, and East Africa. The Blombos Cave site in South Africa, for example, is famous for rectangular slabs of ochre engraved with geometric designs. Using multiple dating techniques, the site was dated to be around 77,000 and 100,000 to 75,000 years old. Ostrich egg shell containers engraved with geometric designs dating to 60,000 years ago were found at Diepkloof, South Africa. Beads and other personal ornamentation have been found from Morocco which might be as much as 130,000 years old; as well, the Cave of Hearths in South Africa has yielded a number of beads dating from significantly prior to 50,000 years ago, and shell beads dating to about 75,000 years ago have been found at Blombos Cave, South Africa.

Specialized projectile weapons as well have been found at various sites in Middle Stone Age Africa, including bone and stone arrowheads at South African sites such as Sibudu Cave (along with an early bone needle also found at Sibudu) dating approximately 72,000-60,000 years ago on some of which poisons may have been used, and bone harpoons at the Central African site of Katanda dating to about 90,000 years ago. Evidence also exists for the systematic heat treating of silcrete stone to increased its flake-ability for the purpose of toolmaking, beginning approximately 164,000 years ago at the South African site of Pinnacle Point and becoming common there for the creation of microlithic tools at about 72,000 years ago.

In 2008, an ochre processing workshop likely for the production of paints was uncovered dating to ca. 100,000 years ago at Blombos Cave, South Africa. Analysis shows that a liquefied pigment-rich mixture was produced and stored in the two abalone shells, and that ochre, bone, charcoal, grindstones and hammer-stones also formed a composite part of the toolkits. Evidence for the complexity of the task includes procuring and combining raw materials from various sources (implying they had a mental template of the process they would follow), possibly using pyrotechnology to facilitate fat extraction from bone, using a probable recipe to produce the compound, and the use of shell containers for mixing and storage for later use. Modern behaviors, such as the making of shell beads, bone tools and arrows, and the use of ochre pigment, are evident at a Kenyan site by 78,000-67,000 years ago. Evidence of early stone-tipped projectile weapons (a characteristic tool of Homo sapiens), the stone tips of javelins or throwing spears, were discovered in 2013 at the Ethiopian site of Gademotta, and date to around 279,000 years ago.

Expanding subsistence strategies beyond big-game hunting and the consequential diversity in tool types has been noted as signs of behavioral modernity. A number of South African sites have shown an early reliance on aquatic resources from fish to shellfish. Pinnacle Point, in particular, shows exploitation of marine resources as early as 120,000 years ago, perhaps in response to more arid conditions inland. Establishing a reliance on predictable shellfish deposits, for example, could reduce mobility and facilitate complex social systems and symbolic behavior. Blombos Cave and Site 440 in Sudan both show evidence of fishing as well. Taphonomic change in fish skeletons from Blombos Cave have been interpreted as capture of live fish, clearly an intentional human behavior.

Humans in North Africa (Nazlet Sabaha, Egypt) are known to have dabbled in chert mining, as early as ≈100,000 years ago, for the construction of stone tools.

Evidence was found in 2018, dating to about 320,000 years ago, at the Kenyan site of Olorgesailie, of the early emergence of modern behaviors including: long-distance trade networks (involving goods such as obsidian), the use of pigments, and the possible making of projectile points. It is observed by the authors of three 2018 studies on the site, that the evidence of these behaviors is approximately contemporary to the earliest known Homo sapiens fossil remains from Africa (such as at Jebel Irhoud and Florisbad), and they suggest that complex and modern behaviors had already begun in Africa around the time of the emergence of anatomically modern Homo sapiens.

In 2019, further evidence of early complex projectile weapons in Africa was found at Aduma, Ethiopia, dated 100,000-80,000 years ago, in the form of points considered likely to belong to darts delivered by spear throwers.

Olduvai Hominid 1 wore facial piercings.

Europe

While traditionally described as evidence for the later Upper Paleolithic Model, European archaeology has shown that the issue is more complex. A variety of stone tool technologies are present at the time of human expansion into Europe and show evidence of modern behavior. Despite the problems of conflating specific tools with cultural groups, the Aurignacian tool complex, for example, is generally taken as a purely modern human signature. The discovery of "transitional" complexes, like "proto-Aurignacian", have been taken as evidence of human groups progressing through "steps of innovation". If, as this might suggest, human groups were already migrating into eastern Europe around 40,000 years and only afterward show evidence of behavioral modernity, then either the cognitive change must have diffused back into Africa or was already present before migration.

In light of a growing body of evidence of Neanderthal culture and tool complexes some researchers have put forth a "multiple species model" for behavioral modernity. Neanderthals were often cited as being an evolutionary dead-end, apish cousins who were less advanced than their human contemporaries. Personal ornaments were relegated as trinkets or poor imitations compared to the cave art produced by H. sapiens. Despite this, European evidence has shown a variety of personal ornaments and artistic artifacts produced by Neanderthals; for example, the Neanderthal site of Grotte du Renne has produced grooved bear, wolf, and fox incisors, ochre and other symbolic artifacts. Although burials are few and controversial, there has been circumstantial evidence of Neanderthal ritual burials. There are two options to describe this symbolic behavior among Neanderthals: they copied cultural traits from arriving modern humans or they had their own cultural traditions comparative with behavioral modernity. If they just copied cultural traditions, which is debated by several authors, they still possessed the capacity for complex culture described by behavioral modernity. As discussed above, if Neanderthals also were "behaviorally modern" then it cannot be a species-specific derived trait.

Asia

Most debates surrounding behavioral modernity have been focused on Africa or Europe but an increasing amount of focus has been placed on East Asia. This region offers a unique opportunity to test hypotheses of multi-regionalism, replacement, and demographic effects. Unlike Europe, where initial migration occurred around 50,000 years ago, human remains have been dated in China to around 100,000 years ago. This early evidence of human expansion calls into question behavioral modernity as an impetus for migration.

Stone tool technology is particularly of interest in East Asia. Following Homo erectus migrations out of Africa, Acheulean technology never seems to appear beyond present-day India and into China. Analogously, Mode 3, or Levallois technology, is not apparent in China following later hominin dispersals. This lack of more advanced technology has been explained by serial founder effects and low population densities out of Africa. Although tool complexes comparative to Europe are missing or fragmentary, other archaeological evidence shows behavioral modernity. For example, the peopling of the Japanese archipelago offers an opportunity to investigate the early use of watercraft. Although one site, Kanedori in Honshu, does suggest the use of watercraft as early as 84,000 years ago, there is no other evidence of hominins in Japan until 50,000 years ago.

The Zhoukoudian cave system near Beijing has been excavated since the 1930s and has yielded precious data on early human behavior in East Asia. Although disputed, there is evidence of possible human burials and interred remains in the cave dated to around 34-20,000 years ago. These remains have associated personal ornaments in the form of beads and worked shell, suggesting symbolic behavior. Along with possible burials, numerous other symbolic objects like punctured animal teeth and beads, some dyed in red ochre, have all been found at Zhoukoudian. Although fragmentary, the archaeological record of eastern Asia shows evidence of behavioral modernity before 50,000 years ago but, like the African record, it is not fully apparent until that time.

See also

Insect farming

From Wikipedia, the free encyclopedia

Insect farming is the practice of raising and breeding insects as livestock, also referred to as minilivestock or micro stock. Insects may be farmed for the commodities they produce (like silk, honey, lac or insect tea), or for them themselves; to be used as food, as feed, as a dye, and otherwise.

Farming of popular insects

Silkworms

Silkworms, the caterpillars of the domestic silkmoth, are kept to produce silk, an elastic fiber made when they are in the process of creating a cocoon. Silk is commonly regarded as a major cash crop and is used in the crafting of many textiles.

Mealworms

The mealworm (Tenebrio molitor L.) is the larvae form of a species of darkling beetles (Coleoptera). The optimum incubation temperature is 25 ̊C - 27 ̊C and its embryonic development lasts 4 – 6 days. It has a long larvae period of about half a year with the optimum temperature and low moisture terminates. The protein content of Tenebrio Molitor larvae, adult, exuvium and excreta are 46.44, 63.34, 32.87, and 18.51% respectively.

Buffaloworms

Buffaloworms, also called lesser mealworms, is the common name of Alphitobius diaperinus. Its larvae superficially resemble small wireworms or true mealworms (Tenebrio spp.). They are approximately 7 to 11 mm in length at last instar. Freshly-emerged larvae are a milky color. The pale color tinge returns to that of the first/second instar larva when preparing to molt, while a yellowish-brown appearance after molting. In addition, it was reported that it has the highest level of iron bioavailability.

Honeybees

Commodities harvested from honeybees include beeswax, bee bread, bee pollen, propolis, royal jelly, brood, and honey. All of the aforementioned are mostly used in food, however, being wax, beeswax has many other uses, such as being used in candles, and propolis may be used as a wood finish. In recent years, wild populations of honeybees have declined significantly.

Lac insects

Lac insects secrete a resinous substance called lac. Lac is used in many applications, from its use in food to being used as a colorant or as a wood finish. The majority of lac farming takes place in India and Thailand, with over 2 million residential employees.

Cochineal

Made into a red dye known as carmine, cochineal are incorporated into many products, including cosmetics, food, paint, and fabric. About 100,000 insects are needed to make a single kilogram of dye. The shade of red the dye yields depends on how the insect is processed. France is the world’s largest importer of carmine.

Crickets

Cricket Shelter Modular Edible Insect Farm, designed by Terreform ONE

Among the hundreds of different types of crickets, the house cricket (Acheta domesticus) is the most common type used for human consumption. The cricket is one of the most nutritious edible insects, and in many parts of the world, crickets are consumed dry-roasted, baked, deep-fried, and boiled. Cricket consumption may take the form of cricket flour, a powder of dried and ground crickets, which is easily integrated in to many food recipes. Crickets are commonly farmed for non-human animal food, as they provide much nutrition to the many species of reptiles, fish, birds and other mammals that consume them. Crickets are normally killed by deep freezing, where they feel no pain and are sedated before neurological death.

Waxworms

Waxworms are the larvae of wax moths. These caterpillars are used widely across the world for food, fish bait, animal testing and plastic degradation. Low in protein but high in fat content, they are a valuable source of fat for many insectivorous organisms. Waxworms are popular in many parts of the world, due to their ability to live in low temperatures and their simplicity in production.

Cockroaches

Cockroaches are farmed by the million in China, and became an area of growth in the early 2000s.

As feed and food

Insects are promising to be used as animal feed. For instance, fly larvae can replace fish meal due to the similar amino acid composition. It is possible to formulate fish meal to increase unsaturated fatty acid. Wild birds and free-range poultry can consume insects inform an adult, larval and pupal naturally. Grasshoppers and moth, as well as the housefly, are reported as the feed supplements of poultry. Apart from that, insects have the potential as the feeds for reptile, soft monkey as well as birds.

Insects are also farmed as food for human consumption (entomophagy). Entomophagy has lasted for as long as, as some sources suggest, 30,000 years. Insects are becoming increasingly viable as a source of protein in the modern diet, as conventional meat forms are very land-intensive and produce large quantities of methane, a greenhouse gas. Insects bred in captivity offer a low space-intensive, highly feed efficient, relatively pollution-free, high-protein source of food for both humans and non-human animals. Insects have a high nutritional value, dense protein content and micronutrient and probiotic potential. Insects such as crickets and mealworms have high concentrations of complete protein, vitamin B12, riboflavin and vitamin A. Insects offer an economical solution to increasingly pressing food security and environmental issues concerning the production and distribution of protein to feed a growing world population. Hundreds of species of crickets, grasshoppers, beetles, moths and various other insects are farmed for human consumption.

Benefits

Purported benefits of entomophagy include:

  • Significantly less amounts of resource and space use, less amounts of waste produced, and emissions of very trace amounts of greenhouse gases.
  • They include many vitamins and essential minerals, contain dietary fiber (which is not present in meat), and are a complete protein. The protein count of 100 g of cricket is nearly equivalent to the amount in 100 g of lean ground beef.
  • As opposed to meat, lower costs are required to care for and produce insects.
  • Faster growth and reproduction rates. Crickets mature rather quickly and are typically full-grown within 3 weeks to a month, and an individual female can lay from 1,200 to 1,500 eggs in three to four weeks. Cattle, however, become adults at 2 years, and the breeding ratio is four breeding animals for each market animal produced.
  • Unlike meat, insects rarely transmit diseases such as H1N1, mad cow disease, or salmonella.

Reduced feed

Cattle use 12 times the amount of feed that crickets do to produce an equal amount of protein. Crickets also only use a quarter of the feed of sheep and one half the amount of feed given to swine and chicken to produce an equivalent amount of protein. Crickets require only two pounds of feed to produce one pound of the finished product. Much of this efficiency is a result of crickets being ectothermic, as in they get their heat from the environment instead of having to expend energy to create their own body heat as typical mammals do.

Nutrient efficiency

Insects are nutrient efficient compared to other meat sources. The insect protein content is comparable to most meat products. Likewise, the fatty acid composition of edible insects is comparable to fish lipids, with high levels of polyunsaturated fatty acids(PUFAs). In addition, all parts on edible insect are efficiently used however, some parts on conventional livestock are not directly available for human consumption.  The nutritional contents of insects vary with species as well as within species depending on their metamorphic stage, their habitat and their diet. For instance, the lipid composition of insects is largely dependent on their diet and metamorphic stage. Insect is abundant in other nutrients, Locusts for example contain between 8 and 20 milligrams of iron for every 100 grams of raw locust. Beef on the other hand contains roughly 6 milligrams of iron in the same amount of meat. Crickets as well are very efficient compared to their nutrients. For every 100 grams of substance crickets contain 12.9 grams of protein, 121 calories, and 5.5 grams of fat. Beef contains more protein containing 23.5 grams in 100 grams of substance, but also has roughly 3 times the calories, and four times the amount of fat as crickets do in 100 grams. So, per 100 grams of substance, crickets contain only half the nutrients of beef, except for iron. High levels of iron are implicated in bowel cancer and heart disease. When considering the protein transition, cold-blood insects are enabling to convert food more efficiently: crickets only need 2.1 kg feed for 1 kg ‘meat’ while poultry and cows need about more than 2 times and 12 times of the feed

Greenhouse gas emissions

The raising of livestock is responsible for 18% of all greenhouse gases emitted. Alternative sources of protein, such as insects, replace protein sourced from livestock and help decrease the number of greenhouse gases emitted from food production. Insect raising has negligible emissions compared to livestock since no farmed insect species besides termites release methane, and none create ammonia.

Land usage

Livestock raising accounts for 70% of agricultural land use. This results in a land-cover change which destroys local ecosystems and displaces people and wildlife. Insect farming is minimally space intensive compared to other conventional livestock, and can even take place in populated urban centers.

Processing methods

With the concerning on animal health and welfare about the tolerance on pain, processing on the insects can be mainly concluded as: harvesting and cleaning, inactivation, heating and drying depending on the final product and rearing methods.

Harvesting and cleaning

Insects at different life stages can be collected by sieving followed by water cleaning when it is necessary to remove biomass or excretion. Before processing, the insects are sieved and stored alive at 4 ℃ for about one day without any feed.

Inactivation

An inactivation step is needed to inactive any enzymes and microbes on the insects. The enzymatic browning reaction (mainly phenolase or phenol oxidase) can cause the brown or black color on the insect, which leads to discoloration and the off-flavor.

Heat-treatment

Sufficient heat treatment is required to kill enterobacteriaceae so that the product can meet the safety requirement. D-value and Z-value can be used to estimate the effectiveness of heat treatments. The temperature and duration of the heating will cause insect proteins' denaturation and changes the functional properties of proteins.

Drying

To prevent spoilage, the products are dried to lower the moisture content and prolong the shelf life. Longer drying time results from a low evaporation rate due to the chitin layer, which can prevent the insect from dehydration during their lifetime. So the product in granules form give the advantages of further drying. In general, insects have a moisture level in the range of 55-65%. A drying process decreasing the moisture content to a level of less than 10% is good for preservation.

Besides the moisture level, oxidation of lipids can cause high levels of unsaturated fatty acids in products. Hence the processing steps influencing the final fat stability in products are necessary to be considered during drying.

Regulations in Europe

The use of insect meal as feed and food is limited by the legislation. Insects can be used in Novel Food according to the guidelines for market authorization of products of the European Union. The European Union Commission accepted the use of insects for fish feed in July 2017. However, the power to promote the scale-up of insects production becomes difficult when only a few participate in this market to change the rules. In Europe, safety documents for certain insects and accompanying products are required by the European Union (EFSA) and NVWA.

See also

Animal husbandry

From Wikipedia, the free encyclopedia
 
Cattle feedlot
Cattle feedlot in Colorado, US

Animal husbandry is the branch of agriculture concerned with animals that are raised for meat, fibre, milk, or other products. It includes day-to-day care, selective breeding and the raising of livestock. Husbandry has a long history, starting with the Neolithic revolution when animals were first domesticated, from around 13,000 BC onwards, antedating farming of the first crops. By the time of early civilisations such as ancient Egypt, cattle, sheep, goats and pigs were being raised on farms.

Major changes took place in the Columbian exchange when Old World livestock were brought to the New World, and then in the British Agricultural Revolution of the 18th century, when livestock breeds like the Dishley Longhorn cattle and Lincoln Longwool sheep were rapidly improved by agriculturalists such as Robert Bakewell to yield more meat, milk, and wool. A wide range of other species such as horse, water buffalo, llama, rabbit and guinea pig are used as livestock in some parts of the world. Insect farming, as well as aquaculture of fish, molluscs, and crustaceans, is widespread. Modern animal husbandry relies on production systems adapted to the type of land available. Subsistence farming is being superseded by intensive animal farming in the more developed parts of the world, where for example beef cattle are kept in high density feedlots, and thousands of chickens may be raised in broiler houses or batteries. On poorer soil such as in uplands, animals are often kept more extensively, and may be allowed to roam widely, foraging for themselves.

Most livestock are herbivores, except for pigs and chickens which are omnivores. Ruminants like cattle and sheep are adapted to feed on grass; they can forage outdoors, or may be fed entirely or in part on rations richer in energy and protein, such as pelleted cereals. Pigs and poultry cannot digest the cellulose in forage, and require other high-protein foods.

Part of the animal–industrial complex, animal agriculture, which kills more than 60 billion non-human land animals every year, is responsible for climate change, ocean acidification, and biodiversity loss, ultimately leading to the Holocene extinction.

Etymology

The verb to husband, meaning "to manage carefully," derives from an older meaning of husband, which in the 14th century referred to the ownership and care of a household or farm, but today means the "control or judicious use of resources," and in agriculture, the cultivation of plants or animals. Farmers and ranchers who raise livestock are considered to practice animal husbandry.

History

Birth of husbandry

Fat-tailed sheep in Afghanistan
The domestication of ruminants, like these fat-tailed sheep in Afghanistan, provided nomads across the Middle East and central Asia with a reliable source of food.

The domestication of livestock was driven by the need to have food on hand when hunting was unproductive. The desirable characteristics of a domestic animal are that it should be useful to the domesticator, should be able to thrive in his or her company, should breed freely, and be easy to tend.

Domestication was not a single event, but a process repeated at various periods in different places. Sheep and goats were the animals that accompanied the nomads in the Middle East, while cattle and pigs were associated with more settled communities.

The first wild animal to be domesticated was the dog. Half-wild dogs, perhaps starting with young individuals, may have been tolerated as scavengers and killers of vermin, and being naturally pack hunters, were predisposed to become part of the human pack and join in the hunt. Prey animals, sheep, goats, pigs and cattle, were progressively domesticated early in the history of agriculture.

Pigs were domesticated in the Near East between 8,500 and 8000 BC, sheep and goats in or near the Fertile Crescent about 8,500 BC, and cattle from wild aurochs in the areas of modern Turkey and Pakistan around 8,500 BC.

A cow was a great advantage to a villager as she produced more milk than her calf needed, and her strength could be put to use as a working animal, pulling a plough to increase production of crops, and drawing a sledge, and later a cart, to bring the produce home from the field. Draught animals were first used about 4,000 BC in the Middle East, increasing agricultural production immeasurably. In southern Asia, the elephant was domesticated by 6,000 BC.

Fossilised chicken bones dated to 5040 BC have been found in northeastern China, far from where their wild ancestors lived in the jungles of tropical Asia, but archaeologists believe that the original purpose of domestication was for the sport of cockfighting.

Meanwhile, in South America, the llama and the alpaca had been domesticated, probably before 3,000 BC, as beasts of burden and for their wool. Neither was strong enough to pull a plough which limited the development of agriculture in the New World.

Horses occur naturally on the steppes of Central Asia, and their domestication, around 3,000 BC in the Black Sea and Caspian Sea region, was originally as a source of meat; use as pack animals and for riding followed. Around the same time, the wild ass was being tamed in Egypt. Camels were domesticated soon after this, with the Bactrian camel in Mongolia and the Arabian camel becoming beasts of burden. By 1000 BC, caravans of Arabian camels were linking India with Mesopotamia and the Mediterranean.

Ancient civilisations

Egyptian hieroglyphic of cattle
Milking cattle in ancient Egypt

In ancient Egypt, cattle were the most important livestock, and sheep, goats, and pigs were also kept; poultry including ducks, geese, and pigeons were captured in nets and bred on farms, where they were force-fed with dough to fatten them.

The Nile provided a plentiful source of fish. Honey bees were domesticated from at least the Old Kingdom, providing both honey and wax.

In ancient Rome, all the livestock known in ancient Egypt were available. In addition, rabbits were domesticated for food by the first century BC. To help flush them out from their burrows, the polecat was domesticated as the ferret, its use described by Pliny the Elder.

Medieval husbandry

Painting of shepherd with sheep
Shepherd with sheep in woven hurdle pen. Medieval France. 15th century, MS Douce 195

In northern Europe, agriculture including animal husbandry went into decline when the Roman empire collapsed. Some aspects such as the herding of animals continued throughout the period. By the 11th century, the economy had recovered and the countryside was again productive.

The Domesday Book recorded every parcel of land and every animal in England: "there was not one single hide, nor a yard of land, nay, moreover ... not even an ox, nor a cow, nor a swine was there left, that was not set down in [the king's] writ." For example, the royal manor of Earley in Berkshire, one of thousands of villages recorded in the book, had in 1086 "2 fisheries worth [paying tax of] 7s and 6d [each year] and 20 acres of meadow [for livestock]. Woodland for [feeding] 70 pigs."

The improvements of animal husbandry in the medieval period in Europe went hand in hand with other developments. Improvements to the plough allowed the soil to be tilled to a greater depth. Horses took over from oxen as the main providers of traction, new ideas on crop rotation were developed and the growing of crops for winter fodder gained ground. Peas, beans and vetches became common; they increased soil fertility through nitrogen fixation, allowing more livestock to be kept.

Columbian exchange

Exploration and colonisation of North and South America resulted in the introduction into Europe of such crops as maize, potatoes, sweet potatoes and manioc, while the principal Old World livestock – cattle, horses, sheep and goats – were introduced into the New World for the first time along with wheat, barley, rice and turnips.

Agricultural Revolution

Lincoln Longwool Sheep
The Lincoln Longwool breed was improved by Robert Bakewell in the 18th century.

Selective breeding for desired traits was established as a scientific practice by Robert Bakewell during the British Agricultural Revolution in the 18th century. One of his most important breeding programs was with sheep. Using native stock, he was able to quickly select for large, yet fine-boned sheep, with long, lustrous wool. The Lincoln Longwool was improved by Bakewell and in turn the Lincoln was used to develop the subsequent breed, named the New (or Dishley) Leicester. It was hornless and had a square, meaty body with straight top lines. These sheep were exported widely and have contributed to numerous modern breeds. Under his influence, English farmers began to breed cattle for use primarily as beef. Long-horned heifers were crossed with the Westmoreland bull to create the Dishley Longhorn.

The semi-natural, unfertilised pastures formed by traditional agricultural methods in Europe were managed by grazing and mowing. As the ecological impact of this land management strategy is similar to the impact of such natural disturbances as a wildfire, this agricultural system shares many beneficial characteristics with a natural habitat, including the promotion of biodiversity. This strategy is declining in Europe today due to the intensification of agriculture. The mechanized and chemical methods used are causing biodiversity to decline.

Husbandry

Systems

Herdwick sheep
Herdwick sheep in an extensive hill farming system, Lake District, England

Traditionally, animal husbandry was part of the subsistence farmer's way of life, producing not only the food needed by the family but also the fuel, fertiliser, clothing, transport and draught power. Killing the animal for food was a secondary consideration, and wherever possible its products, such as wool, eggs, milk and blood (by the Maasai) were harvested while the animal was still alive. In the traditional system of transhumance, people and livestock moved seasonally between fixed summer and winter pastures; in montane regions the summer pasture was up in the mountains, the winter pasture in the valleys.

Animals can be kept extensively or intensively. Extensive systems involve animals roaming at will, or under the supervision of a herdsman, often for their protection from predators. Ranching in the Western United States involves large herds of cattle grazing widely over public and private lands. Similar cattle stations are found in South America, Australia and other places with large areas of land and low rainfall. Ranching systems have been used for sheep, deer, ostrich, emu, llama and alpaca.

In the uplands of the United Kingdom, sheep are turned out on the fells in spring and graze the abundant mountain grasses untended, being brought to lower altitudes late in the year, with supplementary feeding being provided in winter. In rural locations, pigs and poultry can obtain much of their nutrition from scavenging, and in African communities, hens may live for months without being fed, and still produce one or two eggs a week.

Pigs in a barn

At the other extreme, in the more developed parts of the world, animals are often intensively managed; dairy cows may be kept in zero-grazing conditions with all their forage brought to them; beef cattle may be kept in high density feedlots; pigs may be housed in climate-controlled buildings and never go outdoors; poultry may be reared in barns and kept in cages as laying birds under lighting-controlled conditions. In between these two extremes are semi-intensive, often family-run farms where livestock graze outside for much of the year, silage or hay is made to cover the times of year when the grass stops growing, and fertiliser, feed, and other inputs are brought onto the farm from outside.

Feeding

Cattle around an outdoor feeder
Cattle around an outdoor feeder

Animals used as livestock are predominantly herbivorous, the main exceptions being the pig and the chicken which are omnivorous. The herbivores can be divided into "concentrate selectors" which selectively feed on seeds, fruits and highly nutritious young foliage, "grazers" which mainly feed on grass, and "intermediate feeders" which choose their diet from the whole range of available plant material. Cattle, sheep, goats, deer and antelopes are ruminants; they digest food in two steps, chewing and swallowing in the normal way, and then regurgitating the semidigested cud to chew it again and thus extract the maximum possible food value. The dietary needs of these animals is mostly met by eating grass. Grasses grow from the base of the leaf-blade, enabling it to thrive even when heavily grazed or cut.

In many climates grass growth is seasonal, for example in the temperate summer or tropical rainy season, so some areas of the crop are set aside to be cut and preserved, either as hay (dried grass), or as silage (fermented grass). Other forage crops are also grown and many of these, as well as crop residues, can be ensiled to fill the gap in the nutritional needs of livestock in the lean season.

Cattle feed pellets
Cattle feed pellets of pressed linseed

Extensively reared animals may subsist entirely on forage, but more intensively kept livestock will require energy and protein-rich foods in addition. Energy is mainly derived from cereals and cereal by-products, fats and oils and sugar-rich foods, while protein may come from fish or meat meal, milk products, legumes and other plant foods, often the by-products of vegetable oil extraction. Pigs and poultry are non-ruminants and unable to digest the cellulose in grass and other forages, so they are fed entirely on cereals and other high-energy foodstuffs. The ingredients for the animals' rations can be grown on the farm or can be bought, in the form of pelleted or cubed, compound foodstuffs specially formulated for the different classes of livestock, their growth stages and their specific nutritional requirements. Vitamins and minerals are added to balance the diet. Farmed fish are usually fed pelleted food.

Breeding

The breeding of farm animals seldom occurs spontaneously but is managed by farmers with a view to encouraging traits seen as desirable. These include hardiness, fertility, docility, mothering abilities, fast growth rates, low feed consumption per unit of growth, better body proportions, higher yields, and better fibre qualities. Undesirable traits such as health defects and aggressiveness are selected against.

Selective breeding has been responsible for large increases in productivity. For example, in 2007, a typical broiler chicken at eight weeks old was 4.8 times as heavy as a bird of similar age in 1957, while in the thirty years to 2007, the average milk yield of a dairy cow in the United States nearly doubled.

Animal health

Vaccination of a goat

Good husbandry, proper feeding, and hygiene are the main contributors to animal health on the farm, bringing economic benefits through maximised production. When, despite these precautions, animals still become sick, they are treated with veterinary medicines, by the farmer and the veterinarian. In the European Union, when farmers treat their own animals, they are required to follow the guidelines for treatment and to record the treatments given. Animals are susceptible to a number of diseases and conditions that may affect their health. Some, like classical swine fever and scrapie are specific to one type of stock, while others, like foot-and-mouth disease affect all cloven-hoofed animals. Animals living under intensive conditions are prone to internal and external parasites; increasing numbers of sea lice are affecting farmed salmon in Scotland. Reducing the parasite burdens of livestock results in increased productivity and profitability.

Where the condition is serious, governments impose regulations on import and export, on the movement of stock, quarantine restrictions and the reporting of suspected cases. Vaccines are available against certain diseases, and antibiotics are widely used where appropriate. At one time, antibiotics were routinely added to certain compound foodstuffs to promote growth, but this practice is now frowned on in many countries because of the risk that it may lead to antimicrobial resistance in livestock and in humans.

Watercolor drawing of farmyard with cow, horse, pigs, and chickens
Familiar livestock: ink and watercolour drawing of a farmyard with cow, horse, pigs, and chickens, 1869

Governments are concerned with zoonoses, diseases that humans may acquire from animals. Wild animal populations may harbour diseases that can affect domestic animals which may acquire them as a result of insufficient biosecurity. An outbreak of Nipah virus in Malaysia in 1999 was traced back to pigs becoming ill after contact with fruit-eating flying foxes, their faeces and urine. The pigs in turn passed the infection to humans. Avian flu H5N1 is present in wild bird populations and can be carried large distances by migrating birds. This virus is easily transmissible to domestic poultry, and to humans living in close proximity with them. Other infectious diseases affecting wild animals, farm animals and humans include rabies, leptospirosis, brucellosis, tuberculosis and trichinosis.

Range of species

There is no single universally agreed definition of which species are livestock. Widely agreed types of livestock include cattle for beef and dairy, sheep, goats, pigs, and poultry. Various other species are sometimes considered livestock, such as horses, while poultry birds are sometimes excluded. In some parts of the world, livestock includes species such as buffalo, and the South American camelids, the alpaca and llama. Some authorities use much broader definitions to include fish in aquaculture, micro-livestock such as rabbits and rodents like guinea pigs, as well as insects from honey bees to crickets raised for human consumption.

Sheering merino sheep
Shearing a Merino sheep for its wool

Products

Animals are raised for a wide variety of products, principally meat, wool, milk, and eggs, but also including tallow, isinglass and rennet. Animals are also kept for more specialised purposes, such as to produce vaccines and antiserum (containing antibodies) for medical use. Where fodder or other crops are grown alongside animals, manure can serve as a fertiliser, returning minerals and organic matter to the soil in a semi-closed organic system.

Branches

Dairy

Rotary milking parlour
A modern rotary milking parlour, Germany

Although all mammals produce milk to nourish their young, the cow is predominantly used throughout the world to produce milk and milk products for human consumption. Other animals used to a lesser extent for this purpose include sheep, goats, camels, buffaloes, yaks, reindeer, horses and donkeys.

All these animals have been domesticated over the centuries, being bred for such desirable characteristics as fecundity, productivity, docility and the ability to thrive under the prevailing conditions. Whereas in the past, cattle had multiple functions, modern dairy cow breeding has resulted in specialised Holstein Friesian-type animals that produce large quantities of milk economically. Artificial insemination is widely available to allow farmers to select for the particular traits that suit their circumstances.

Whereas in the past, cows were kept in small herds on family farms, grazing pastures and being fed hay in winter, nowadays there is a trend towards larger herds, more intensive systems, the feeding of silage and "zero grazing", a system where grass is cut and brought to the cow, which is housed year-round.

In many communities, milk production is only part of the purpose of keeping an animal which may also be used as a beast of burden or to draw a plough, or for the production of fibre, meat and leather, with the dung being used for fuel or for the improvement of soil fertility. Sheep and goats may be favoured for dairy production in climates and conditions that do not suit dairy cows.

Meat

Hereford cow
The Hereford is a hardy breed of beef cattle, now raised in many countries around the world.
 

Meat, mainly from farmed animals, is a major source of dietary protein around the world, averaging about 8% of man's energy intake. The actual types eaten depend on local preferences, availability, cost and other factors, with cattle, sheep, pigs and goats being the main species involved. Cattle generally produce a single offspring annually which takes more than a year to mature; sheep and goats often have twins and these are ready for slaughter in less than a year; pigs are more prolific, producing more than one litter of up to about 11 piglets each year. Horses, donkeys, deer, buffalo, llamas, alpacas, guanacos and vicunas are farmed for meat in various regions. Some desirable traits of animals raised for meat include fecundity, hardiness, fast growth rate, ease of management and high food conversion efficiency. About half of the world's meat is produced from animals grazing on open ranges or on enclosed pastures, the other half being produced intensively in various factory-farming systems; these are mostly cows, pigs or poultry, and often reared indoors, typically at high densities.

Poultry

Battery hens
Battery hens, Brazil
 

Poultry, kept for their eggs and for their meat, include chickens, turkeys, geese and ducks. The great majority of laying birds used for egg production are chickens. Methods for keeping layers range from free-range systems, where the birds can roam as they will but are housed at night for their own protection, through semi-intensive systems where they are housed in barns and have perches, litter and some freedom of movement, to intensive systems where they are kept in cages. The battery cages are arranged in long rows in multiple tiers, with external feeders, drinkers, and egg collection facilities. This is the most labour saving and economical method of egg production but has been criticised on animal welfare grounds as the birds are unable to exhibit their normal behaviours.

In the developed world, the majority of the poultry reared for meat is raised indoors in big sheds, with automated equipment under environmentally controlled conditions. Chickens raised in this way are known as broilers, and genetic improvements have meant that they can be grown to slaughter weight within six or seven weeks of hatching. Newly hatched chicks are restricted to a small area and given supplementary heating. Litter on the floor absorbs the droppings and the area occupied is expanded as they grow. Feed and water is supplied automatically and the lighting is controlled. The birds may be harvested on several occasions or the whole shed may be cleared at one time.

A similar rearing system is usually used for turkeys, which are less hardy than chickens, but they take longer to grow and are often moved on to separate fattening units to finish. Ducks are particularly popular in Asia and Australia and can be killed at seven weeks under commercial conditions.

Aquaculture

Freshwater fish farm
Freshwater fish farming, France
 

Aquaculture has been defined as "the farming of aquatic organisms including fish, molluscs, crustaceans and aquatic plants and implies some form of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc. Farming also implies individual or corporate ownership of the stock being cultivated." In practice it can take place in the sea or in freshwater, and be extensive or intensive. Whole bays, lakes or ponds may be devoted to aquaculture, or the farmed animal may be retained in cages (fish), artificial reefs, racks or strings (shellfish). Fish and prawns can be cultivated in rice paddies, either arriving naturally or being introduced, and both crops can be harvested together.

Fish hatcheries provide larval and juvenile fish, crustaceans and shellfish, for use in aquaculture systems. When large enough these are transferred to growing-on tanks and sold to fish farms to reach harvest size. Some species that are commonly raised in hatcheries include shrimps, prawns, salmon, tilapia, oysters and scallops. Similar facilities can be used to raise species with conservation needs to be released into the wild, or game fish for restocking waterways. Important aspects of husbandry at these early stages include selection of breeding stock, control of water quality and nutrition. In the wild, there is a massive amount of mortality at the nursery stage; farmers seek to minimise this while at the same time maximising growth rates.

Insects

Crickets
Crickets being raised for human consumption, Thailand
 

Bees have been kept in hives since at least the First Dynasty of Egypt, five thousand years ago, and man had been harvesting honey from the wild long before that. Fixed comb hives are used in many parts of the world and are made from any locally available material. In more advanced economies, where modern strains of domestic bee have been selected for docility and productiveness, various designs of hive are used which enable the combs to be removed for processing and extraction of honey. Quite apart from the honey and wax they produce, honey bees are important pollinators of crops and wild plants, and in many places hives are transported around the countryside to assist in pollination.

Sericulture, the rearing of silkworms, was first adopted by the Chinese during the Shang dynasty. The only species farmed commercially is the domesticated silkmoth. When it spins its cocoon, each larva produces an exceedingly long, slender thread of silk. The larvae feed on mulberry leaves and in Europe, only one generation is normally raised each year as this is a deciduous tree. In China, Korea and Japan however, two generations are normal, and in the tropics, multiple generations are expected. Most production of silk occurs in the Far East, with a synthetic diet being used to rear the silkworms in Japan.

Insects form part of the human diet in many cultures. In Thailand, crickets are farmed for this purpose in the north of the country, and palm weevil larvae in the south. The crickets are kept in pens, boxes or drawers and fed on commercial pelleted poultry food, while the palm weevil larvae live on cabbage palm and sago palm trees, which limits their production to areas where these trees grow. Another delicacy of this region is the bamboo caterpillar, and the best rearing and harvesting techniques in semi-natural habitats are being studied.

Effects

Environmental impact

Cattle
Livestock production requires large areas of land.

Animal husbandry has a significant impact on the world environment. Being a part of the animal–industrial complex, animal agriculture is the primary driver of climate change, ocean acidification, biodiversity loss, and of the crossing of almost every other planetary boundary, in addition to killing more than 60 billion non-human land animals annually. It is responsible for somewhere between 20 and 33% of the fresh water usage in the world, and livestock, and the production of feed for them, occupy about a third of the earth's ice-free land. Livestock production is a contributing factor in species extinction, desertification, and habitat destruction. Animal agriculture contributes to species extinction in various ways and is the primary driver of the Holocene extinction. Habitat is destroyed by clearing forests and converting land to grow feed crops and for animal grazing, while predators and herbivores are frequently targeted and hunted because of a perceived threat to livestock profits; for example, animal husbandry is responsible for up to 91% of the deforestation in the Amazon region. In addition, livestock produce greenhouse gases. Cows produce some 570 million cubic metres of methane per day, that accounts for from 35 to 40% of the overall methane emissions of the planet. Livestock is responsible for 65% of all human-related emissions of the powerful and long-lived greenhouse gas nitrous oxide.

As a result, ways of mitigating animal husbandry's environmental impact are being studied. Strategies include using biogas from manure, genetic selection, immunization, rumen defaunation, outcompetition of methanogenic archaea with acetogens, introduction of methanotrophic bacteria into the rumen, diet modification and grazing management, among others. A diet change (with Asparagopsis taxiformis) allowed for a reduction of up to 99% of methane production in an experimental study with three ruminants.

Animal welfare

Since the 18th century, people have become increasingly concerned about the welfare of farm animals. Possible measures of welfare include longevity, behavior, physiology, reproduction, freedom from disease, and freedom from immunosuppression. Standards and laws for animal welfare have been created worldwide, broadly in line with the most widely held position in the western world, a form of utilitarianism: that it is morally acceptable for humans to use non-human animals, provided that no unnecessary suffering is caused, and that the benefits to humans outweigh the costs to the livestock. An opposing view is that animals have rights, should not be regarded as property, are not necessary to use, and should never be used by humans. Live export of animals has risen to meet increased global demand for livestock such as in the Middle East. Animal rights activists have objected to long-distance transport of animals; one result was the banning of live exports from New Zealand in 2003.

In culture

Cartoon of John Bull giving his breeches to save his bacon
Opening of the budget; – or – John Bull giving his breeches to save his bacon by James Gillray (d. 1815)

Since the 18th century, the farmer John Bull has represented English national identity, first in John Arbuthnot's political satires, and soon afterwards in cartoons by James Gillray and others including John Tenniel. He likes food, beer, dogs, horses, and country sports; he is practical and down to earth, and anti-intellectual.

Farm animals are widespread in books and songs for children; the reality of animal husbandry is often distorted, softened, or idealized, giving children an almost entirely fictitious account of farm life. The books often depict happy animals free to roam in attractive countryside, a picture completely at odds with the realities of the impersonal, mechanized activities involved in modern intensive farming.

Illustration of dressed pigs

Pigs, for example, appear in several of Beatrix Potter's "little books", as Piglet in A.A. Milne's Winnie the Pooh stories, and somewhat more darkly (with a hint of animals going to slaughter) as Babe in Dick King-Smith's The Sheep-Pig, and as Wilbur in E. B. White's Charlotte's Web. Pigs tend to be "bearers of cheerfulness, good humour and innocence". Many of these books are completely anthropomorphic, dressing farm animals in clothes and having them walk on two legs, live in houses, and perform human activities. The children's song "Old MacDonald Had a Farm" describes a farmer named MacDonald and the various animals he keeps, celebrating the noises they each make.

Many urban children experience animal husbandry for the first time at a petting farm; in Britain, some five million people a year visit a farm of some kind. This presents some risk of infection, especially if children handle animals and then fail to wash their hands; a strain of E. coli infected 93 people who had visited a British interactive farm in an outbreak in 2009. Historic farms such as those in the United States offer farmstays and "a carefully curated version of farming to those willing to pay for it", sometimes giving visitors a romanticised image of a pastoral idyll from an unspecified time in the pre-industrial past.

See also

Teacher

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Teacher A teacher in a classroom at a secondary school in ...