出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/09/19 06:10:29」(JST)
Livestock are domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. This article does not discuss poultry or farmed fish, although these, especially poultry, are commonly included within the meaning of "livestock".
Livestock generally are raised for profit. Raising animals (animal husbandry) is a component of modern agriculture. It has been practiced in many cultures since the transition to farming from hunter-gather lifestyles.
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Animal-rearing has its origins in the transition of cultures to settled farming communities rather than hunter-gatherer lifestyles. Animals are ‘domesticated’ when their breeding and living conditions are controlled by humans. Over time, the collective behaviour, life cycle, and physiology of livestock have changed radically. Many modern farm animals are unsuited to life in the wild. Dogs were domesticated in East Asia about 15,000 years ago, Goats and sheep were domesticated around 8000 BCE in Asia. Swine or pigs were domesticated by 7000 BCE in the Middle East and China. The earliest evidence of horse domestication dates to around 4000 BCE[1]
Older English sources, such as the King James Version of the Bible, refer to livestock in general as "cattle", as opposed to the word "deer", which then was used for wild animals which were not owned. The word cattle is derived from Middle English chatel, which meant all kinds of movable personal property,[2] including of course livestock, which was differentiated from non-movable real-estate ("real property"). In later English, sometimes smaller livestock was called "small cattle" in that sense of movable property on land, which was not automatically bought or sold with the land. Today, the modern meaning of "cattle", without a qualifier, usually refers to domesticated bovines (see Cattle).[citation needed] Other species of the genus Bos sometimes are called wild cattle.
The term "livestock" is nebulous and may be defined narrowly or broadly. On a broader view, livestock refers to any breed or population of animal kept by humans for a useful, commercial purpose. This can mean domestic animals, semi-domestic animals, or captive wild animals. Semi-domesticated refers to animals which are only lightly domesticated or of disputed status. These populations may also be in the process of domestication. Some people may use the term livestock to refer to only domestic animals or even to only red meat animals.
| Animal / Type | Domestication status | Wild ancestor | Time of first captivity, domestication | Area of first captivity, domestication | Current commercial uses | Picture |
|---|---|---|---|---|---|---|
| Alpaca Mammal, herbivore |
domestic | Vicuña | Between 5000 BC and 4000 BC | Andes | wool | |
| Banteng Mammal, herbivore |
domestic | Banteng | Unknown | Southeast Asia, Java | meat, milk, draught | |
| Bison Mammal, herbivore |
captive (see also Beefalo) | N/A | Late 19th Century | North America | meat, leather | |
| Camel Mammal, herbivore |
domestic | Wild Dromedary and Bactrian camels | Between 4000 BC and 1400 BC | Asia | mount, pack animal, meat, dairy, camel hair | |
| Cat Mammal, carnivore |
domestic | African Wildcat | 7500 BC [3][4][5] | Near East | pest control, companionship, meat | |
| Cattle Mammal, herbivore |
domestic | Aurochs (extinct) | 6000 BC | Southwest Asia, India, North Africa (?) | Meat (beef, veal, blood), dairy, leather, draught | |
| Deer Mammal, herbivore |
captive | N/A | 1970[citation needed] | North America[citation needed] | Meat (venison), leather, antlers, antler velvet | |
| Dog Mammal, omnivore |
domestic | Wolf | 12000 BC | pack animal, draught, hunting, herding, searching/gathering, watching/guarding, meat | ||
| Donkey Mammal, herbivore |
domestic | African Wild Ass | 4000 BC | Egypt | mount, pack animal, draught, meat, dairy | |
| Gayal Mammal, herbivore |
domestic | Gaur | Unknown | Southeast Asia | meat, draught | |
| Goat Mammal, herbivore |
domestic | Wild Goat | 8000 BC | Southwest Asia | Dairy, meat, wool, leather, light draught | |
| Guinea pig Mammal, herbivore |
domestic | Cavia tschudii | 5000 BC | South America | Meat | |
| Horse Mammal, herbivore |
domestic | Wild horse | 4000 BC | Eurasian Steppes | Mount, draught, dairy, meat, pack animal | |
| Llama Mammal, herbivore |
domestic | Guanaco | 3500 BC | Andes | light mount, pack animal, draught, meat, wool | |
| Mule Mammal, herbivore |
domestic | Sterile hybrid of donkey and horse | mount, pack animal, draught | |||
| Pig Mammal, omnivore |
domestic | Wild boar | 7000 BC | Eastern Anatolia | Meat (pork, bacon, etc.), leather, pet, research | |
| Rabbit Mammal, herbivore |
domestic | Wild rabbit | between AD 400-900 | France | Meat, fur, leather, pet, research | |
| Reindeer Mammal, herbivore |
semi-domestic | reindeer | 3000 BC | Northern Russia | Meat, leather, antlers, dairy, draught, | |
| Sheep Mammal, herbivore |
domestic | Asiatic mouflon sheep | Between 11000 BC-9000 BC | Southwest Asia | Wool, dairy, leather, meat (mutton, lamb) | |
| Water buffalo Mammal, herbivore |
domestic | Wild Asian Water buffalo, (Arni) | 4000 BC | South Asia | mount, draught, meat, dairy | |
| Yak Mammal, herbivore |
domestic | Yak | 2500 BC | Tibet, Nepal | Meat, dairy, wool, mount, pack animal, draught |
‘Livestock’ are defined, in part, by their end purpose as the production of food, fiber and/or labor.
The economic value of livestock includes:
During the history of animal husbandry, many secondary products have arisen in an attempt to increase carcass utilization and reduce waste. For example, animal offal and non-edible parts may be transformed into products such as pet food and fertilizer. In the past, such waste products were sometimes also fed to livestock as well. However, intra-species recycling poses a disease risk, threatening animal and even human health (see bovine spongiform encephalopathy (BSE), scrapie and prion). Due primarily to BSE (mad cow disease), feeding animal scraps to animals has been banned in many countries, at least in regards to ruminants and pigs.
Farming practices vary dramatically worldwide and between types of animals. Livestock are generally kept in an enclosure, are fed by human-provided food[citation needed] and are intentionally bred, but some livestock are not enclosed, or are fed by access to natural foods, or are allowed to breed freely, or any combination thereof. Livestock raising historically was part of a nomadic or pastoral form of material culture. The herding of camels and reindeer in some parts of the world remains unassociated with sedentary agriculture. The transhumance form of herding in the Sierra Nevada Mountains of California still continues, as cattle, sheep or goats are moved from winter pasture in lower elevation valleys to spring and summer pasture in the foothills and alpine regions, as the seasons progress. Cattle were raised on the open range in the Western United States and Canada, on the Pampas of Argentina, and other prairie and steppe regions of the world.
The enclosure of livestock in pastures and barns is a relatively new development in the history of agriculture. When cattle are enclosed, the type of ‘enclosure’ may vary from a small crate, a large fenced pasture or a paddock. The type of feed may vary from natural growing grass, to highly sophisticated processed feed. Animals are usually intentionally bred through artificial insemination or through supervised mating. Indoor production systems are generally used only for pigs and poultry, as well as for veal cattle. Indoor animals are generally farmed intensively, as large space requirements would make indoor farming unprofitable and impossible. However, indoor farming systems are controversial due to the waste they produce, odour problems, the potential for groundwater contamination and animal welfare concerns. (For further discussion on intensively farmed livestock, see factory farming, and intensive pig farming).
Other livestock are farmed outside, although the size of enclosure and level of supervision may vary. In large open ranges animals may be only occasionally inspected or yarded in "round-ups" or a muster (livestock). Herding dogs may be used for mustering livestock as are cowboys, stockmen and jackaroos on horses, or with vehicles and also by helicopters. Since the advent of barbed wire (in the 1870s) and electric fence technology, fencing pastures has become much more feasible and pasture management simplified. Rotation of pasturage is a modern technique for improving nutrition and health while avoiding environmental damage to the land. In some cases very large numbers of animals may be kept in indoor or outdoor feeding operations (on feedlots), where the animals' feed is processed, offsite or onsite, and stored on site then fed to the animals.
Livestock - especially cattle - may be branded to indicate ownership and age, but in modern farming identification is more likely to be indicated by means of ear tags than branding. Sheep are also frequently marked by means of ear marks and/or ear tags. As fears of mad cow disease and other epidemic illnesses mount, the use of implants to monitor and trace animals in the food production system is increasingly common, and sometimes required by government regulations.
Modern farming techniques seek to minimize human involvement, increase yield, and improve animal health. Economics, quality and consumer safety all play a role in how animals are raised. Drug use and feed supplements (or even feed type) may be regulated, or prohibited, to ensure yield is not increased at the expense of consumer health, safety or animal welfare. Practices vary around the world, for example growth hormone use is permitted in the United States, but not in stock to be sold to the European Union. The improvement of health, using modern farming techniques, on the part of animals has come into question. Feeding corn to cattle, which have historically eaten grasses, is an example; where the cattle are less adapted, the rumen pH changes to more acidic, leading to liver damage and other difficulties.[citation needed] The US F.D.A. still allows feedlots to feed nonruminant animal proteins to cattle. For example, feeding chicken manure and poultry meal is acceptable for cattle, and beef or pork meat and bone meal is being fed to chickens.
Livestock farmers have suffered from wild animal predation and theft by rustlers. In North America, gray wolf, grizzly bear, cougar, black bear, and coyote are sometimes considered a threat to livestock. In Eurasia and Africa, wolf, brown bear, leopard, tiger, lion, dhole, black bear, spotted hyena, and others cause livestock deaths to varying degrees. In Australia, the dingo, foxes, wedge-tailed eagles, hunting and domestic dogs (especially) cause problems for livestock farmers because they may kill seemingly for fun, leaving the carcass uneaten.[6][7] In Latin America, feral dogs cause livestock deaths in nightfall.
Livestock diseases compromise animal welfare, reduce productivity, and can infect humans. Animal diseases may be tolerated, reduced through animal husbandry, or reduced through antibiotics and vaccines. In developing countries, animal diseases are tolerated in animal husbandry, resulting in considerably reduced productivity, especially given the low health-status of many developing country herds. Disease management for gains in productivity is often the first step taken in implementing an agriculture policy.
Disease management can be achieved through changes in animal husbandry. These measures may aim to control spread using biosecurity measures, such as controlling animal mixing, controlling entry to farm lots and the use of protective clothing, and quarantining sick animals. Diseases also may be controlled by the use of vaccines and antibiotics. Antibiotics in sub-therapeutic doses may also be used as a growth-promoter, increasing growth by 10-15%.[8] The issue of antibiotic resistance has limited the practices of preventative dosing such as antibiotic-laced feed. Countries will often require the use of veterinary certificates before transporting, selling or showing animals. Disease-free areas often rigorously enforce rules for entry of potentially diseased animals, including quarantine.
Since many livestock are herd animals, they were historically driven to market "on the hoof" to a town or other central location. During the period after the American Civil War, the abundance of Longhorn cattle in Texas, and the demand for beef in Northern markets, led to the implementation of the Old West cattle drive. The method is still used in some parts of the world. Truck transport is now common in developed countries. Local and regional livestock auctions and commodity markets facilitate trade in livestock. In other areas, livestock may be bought and sold in a bazaar, such as may be found in many parts of Central Asia, or a flea market type setting.
Stock shows and fairs are events where people bring their best livestock to compete with one another. Organizations like 4-H, Block & Bridle, and FFA encourage young people to raise livestock for show purposes. Special feeds are purchased and hours may be spent prior to the show grooming the animal to look its best. In cattle, sheep, and swine shows, the winning animals are frequently auctioned off to the highest bidder, and the funds are placed into a scholarship fund for its owner. The movie Grand Champion, released in 2004, is the story of a young Texas boy's experience raising a prize steer.
The issue of raising livestock for human benefit raises the issue of the relationship between humans and animals, in terms of the status of animals and obligations of people. Animal welfare is the viewpoint that animals under human care should be treated in such a way that they do not suffer unnecessarily. What is ‘unnecessary’ suffering may vary. Generally, though, the animal welfare perspective is based on an interpretation of scientific research on farming practices. By contrast, animal rights is the viewpoint that using animals for human benefit is, by its nature, generally exploitation, regardless of the farming practices used. Animal rights activists would generally be vegan or vegetarian, whereas it is consistent with the animal welfare perspective to eat meat, depending on production processes.
Animal welfare groups generally seek to generate public discussion on livestock raising practices and secure greater regulation and scrutiny of livestock industry practices. Animal rights groups usually seek the abolition of livestock farming, although some groups may recognise the necessity of achieving more stringent regulation first. Animal welfare groups, such as the RSPCA, are often, in first world countries, given a voice at governmental level in the development of policy. Animal rights groups find it harder to find methods of input, and may go further and advocate civil disobedience or violence.
A number of animal husbandry practices have been the subject of campaigns in the 1990s and 2000s and have led to legislation in some countries. Confinement of livestock in small and unnatural spaces is often done for economic or health reasons. Animals may be kept in the minimum size of cage or pen with little or no space to exercise. Where livestock are used as a source of power, they may be pushed beyond their limits to the point of exhaustion. The public visibility of this abuse meant it was one of the first areas to receive legislation in the nineteenth century in European countries, but it still goes on in parts of Asia. Broiler hens may be de-beaked, pigs may have deciduous teeth pulled, cattle may be de-horned and branded, dairy cows and sheep may have tails cropped, merino sheep may be mulesed, and many types of male animals are castrated. Animals may be transported long distances to market and slaughter. Overcrowded conditions, heat from tropical-area shipping and lack of food, water and rest breaks have been subject to legislation and protest. (See Live Export) Slaughter of livestock was an early target for legislation. Campaigns continue to target Halal and Kosher religious ritual slaughter.
At first reports like the United Nations report "Livestock's Long Shadow" cast a pall over the livestock sector (primarily cattle, chickens, and pigs) for 'emerging as one of the top two or three most significant contributors to our most serious environmental problems.' The United Nations controversially[citation needed] included emissions from deforestation as part of its methodology. Rather than the 18% figure that placed on the sector as major contributor to emissions, the real figure, less deforestation is actually 12%[citation needed]. In April 2008, the [United States Environmental Protection Agency] released a major stocktake of emissions in the United States entitled Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006.[9] On 6.1 it found "In 2006, the agricultural sector was responsible for emissions of 454.1 teragrams of CO2 equivalent (Tg CO2 Eq.), or 6 percent of total U.S. greenhouse gas emissions." By way of comparison, transportation in the US produces more than 25% of all emissions. In 2009, Worldwatch Institute released a report which revealed 51% of Greenhouse Gas emissions were from the animal agriculture sector[10].
The issue of livestock as a major policy focus remains, especially when dealing with problems of deforestation in neotropical areas, land degradation, climate change and air pollution, water shortage and water pollution, and loss of biodiversity. A research team at Obihiro University of Agriculture and Veterinary Medicine in Hokkaidō found that supplementing the animals' diet with cysteine, a type of amino acid, and nitrate can reduce the methane gas produced, without jeopardising the cattle's productivity or the quality of their meat and milk.[11]
Deforestation Deforestation impacts the carbon cycle (and global and regional climate) and causes habitat loss of many species. Forests that are sinks for the carbon cycle are lost through deforestation. Forests are either logged or burned to make room for grasslands, often the area needed is extensive. Deforestation can also create fragmentation, allowing only patches of habitat for species to live. If patches are distant and small, gene flow is reduced, habitat is altered, edge effects will occur and there will be more opportunities for invasive species to intrude.[12]
Land Degradation Research from the University of Botswana in 2008 has found that farmers' common practice of overstocking cattle to cope with drought losses made ecosystems more vulnerable and risked long term damage to cattle herds, in turn, by actually depleting scarce biomass. The study of the Kgatleng district of Botswana predicted that by 2050, the cycle of mild drought is likely to become shorter for the region (18 months instead of two years) due to climate change.[13]
Climate Change & Air Pollution Methane is one of the gasses emitted from livestock manure; it persists for long periods of time and is a green house gas. It is the second most abundant green house gas after carbon dioxide.[14] Even though there is less methane then carbon dioxide its ability to warm the atmosphere is 25 times greater.[14]
Water Shortage Livestock require water for consumption but also for watering drops necessary for feed. Grains are often used to feed live stock about 50% of US grains produced does and 40% of world grains produced does as well.[15] Grain and in general crop production requires various amounts of water, it takes 100,000 liters of water for a kilogram of grain fed beef, compared to wheat, which takes 900 liters.[15]
Water Pollution Fertilizers that often contain manure are used to grow such crops (as cereal and fodder) that have phosphorus and nitrogen in them, 95% of which is estimated to be lost to the environment.[16] The pollutants then cause dead zones for plants and aquatic animals due to the lack of oxygen in the water.[17] The lack of oxygen is known as eutrophication, where organisms present in the water grow excessively and then later decompose using up the oxygen in the water. The most prominent example of such is the Gulf of Mexico, where much of the nutrients in fertilizer used in the mid west are funneled down the Mississippi River into the Gulf causing massive dead zones. Another pollutant not most commonly though of is antibiotics and hormones. In southern Asia vultures that consumed carcasses of livestock declined 95% due to antibiotic known as Diclofenac.[12]
Alternatives Researchers in Australia are looking into the possibility of reducing methane from cattle and sheep by introducing digestive bacteria from kangaroo intestines into livestock.[18]
In semi arid rangelands such as the Great Plains in the U.S., there has been research that provides evidence that livestock can be beneficial to maintaining grassland habitats. Livestock create and maintain habitat for big game species [19]
United States federal legislation sometimes more narrowly defines the term to make specified agricultural commodities either eligible, or ineligible, for a program or activity. For example, the Livestock Mandatory Reporting Act of 1999 (P.L. 106-78, Title IX) defines livestock only as cattle, swine, and lambs. However, 1988 disaster assistance legislation defined the term as “cattle, sheep, goats, swine, poultry (including egg-producing poultry), equine animals used for food or in the production of food, fish used for food, and other animals designated by the Secretary.”[20]
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| リンク元 | 「livestock」「domestic animal」「家畜」 |
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