Мясо: история, производство и влияние на здоровье и окружающую среду.

Animal flesh eaten as food

Meat is animal tissue, often muscle, that is eaten as food. Humans have hunted and farmed other animals for meat since prehistory. The Neolithic Revolution allowed the domestication of animals, including chickens, sheep, goats, pigs, horses, and cattle, starting around 11,000 years ago. Since then, selective breeding has enabled farmers to produce meat with the qualities desired by producers and consumers. Meat is mainly composed of water, protein, and fat. Its quality is affected by many factors, including the genetics and nutritional status of the animal involved. It is edible raw, but is normally eaten cooked, such as by stewing or roasting, or processed, such as by smoking or salting. Bacteria and fungi decompose and spoil unprocessed meat within hours or days. The consumption of meat, especially red and processed meat, causes health effects including increased risks of cancer, coronary heart disease, and diabetes. Meat production is a major contributor to environmental issues including global warming, pollution, and biodiversity loss, at every scale from local to global. Meat is important to economies and cultures around the world. Some people choose not to eat meat (vegetarians) for reasons such as ethics, environmental effects, health concerns, or religious dietary rules.

The word meat comes from the Old English word mete, meaning food in general. In modern usage, meat primarily means skeletal muscle with its associated fat and connective tissue, but it can include offal, other edible organs such as liver and kidney. The term is sometimes used in a more restrictive sense to mean the flesh of mammalian species (pigs, cattle, sheep, goats, etc.) raised and prepared for human consumption, to the exclusion of fish, other seafood, insects, poultry, or other animals. English has specialized terms for the meat of particular animals, deriving from the Norman conquest of England in 1066: while the animals retained their English names, their meat as brought to the tables of the invaders was named in Norman French. These names came to be used by the entire population. +Meat of is called:Chicken East Asia Cockfighting 7,000Horse Central Asia Draft, riding 5,500

In the postwar period, governments gave farmers guaranteed prices to increase animal production. The effect was to raise output at the cost of increased inputs such as of animal feed and veterinary medicines, as well as of animal disease and environmental pollution. In 1966, the United States, the United Kingdom and other industrialized nations, began factory farming of beef and dairy cattle and domestic pigs. In 1990 intensive animal farming accounted for 30% of world meat production and by 2005, this had risen to 40%.

Several factors affect the growth and development of meat.

Heat regulation in livestock is of economic significance, as mammals attempt to maintain a constant optimal body temperature. Low temperatures tend to prolong animal development and high temperatures tend to delay it. Depending on their size, body shape and insulation through tissue and fur, some animals have a relatively narrow zone of temperature tolerance and others (e. g. cattle) a broad one. Static magnetic fields, for reasons still unknown, retard animal development.

The quality and quantity of usable meat depends on the animal's plane of nutrition, i. e., whether it is over or underfed. Scientists disagree about how exactly the plane of nutrition influences carcase composition. The composition of the diet, especially the amount of protein provided, is an important factor regulating animal growth. Ruminants, which may digest cellulose, are better adapted to poor quality diets, but their ruminal microorganisms degrade high quality protein if supplied in excess. Because producing high quality protein animal feed is expensive, several techniques are employed or experimented with to ensure maximum utilization of protein. These include the treatment of feed with formalin to protect amino acids during their passage through the rumen, the recycling of manure by feeding it back to cattle mixed with feed concentrates, or the conversion of petroleum hydrocarbons to protein through microbial action. In plant feed, environmental factors influence the availability of crucial nutrients or micronutrients, a lack or excess of which can cause a great many ailments. In Australia, where the soil contains limited phosphate, cattle are fed additional phosphate to increase the efficiency of beef production. Also in Australia, cattle and sheep in certain areas were often found losing their appetite and dying in the midst of rich pasture; this was found to be a result of cobalt deficiency in the soil. Plant toxins are a risk to grazing animals; for instance, sodium fluoroacetate, found in some African and Australian plants, kills by disrupting the cellular metabolism. Some man made pollutants such as methylmercury and some pesticide residues present a particular hazard as they bioaccumulate in meat, potentially poisoning consumers.

Practices such as confinement in factory farming have generated concerns for animal welfare. Animals have abnormal behaviors such as tail biting, cannibalism, and feather pecking. Invasive procedures such as beak trimming, castration, and ear notching have similarly been questioned. Breeding for high productivity may affect welfare, as when broiler chickens are bred to be very large and to grow rapidly. Broilers often have leg deformities and become lame, and many die from the stress of handling and transport.

Meat producers may seek to improve the fertility of female animals through the administration of gonadotrophic or ovulation inducing hormones. In pig production, sow infertility is a common problem – possibly due to excessive fatness. No methods currently exist to augment the fertility of male animals. Artificial insemination is now routinely used to produce animals of the best possible genetic quality, and the efficiency of this method is improved through the administration of hormones that synchronize the ovulation cycles within groups of females. Growth hormones, particularly anabolic agents such as steroids, are used in some countries to accelerate muscle growth in animals. This practice has given rise to the beef hormone controversy, an international trade dispute. It may decrease the tenderness of meat, although research on this is inconclusive, and have other effects on the composition of the muscle flesh. Where castration is used to improve control over male animals, its side effects can be counteracted by the administration of hormones. Myostatin has been used to produce muscle hypertrophy. Sedatives may be administered to animals to counteract stress factors and increase weight gain. The feeding of antibiotics to certain animals increases growth rates. This practice is particularly prevalent in the US, but has been banned in the EU, partly because it causes antimicrobial resistance in pathogenic microorganisms.

The biochemical composition of meat varies in complex ways depending on the species, breed, sex, age, plane of nutrition, training and exercise of the animal, as well as on the anatomical location of the musculature involved. Even between animals of the same litter and sex there are considerable differences in such parameters as the percentage of intramuscular fat. Adult mammalian muscle consists of roughly 75 percent water, 19 percent protein, 2.5 percent intramuscular fat, 1.2 percent carbohydrates and 2.3 percent other soluble substances. These include organic compounds, especially amino acids, and inorganic substances such as minerals. Muscle proteins are either soluble in water (sarcoplasmic proteins, about 11.5 percent of total muscle mass) or in concentrated salt solutions (myofibrillar proteins, about 5.5 percent of mass). There are several hundred sarcoplasmic proteins. Most of them – the glycolytic enzymes – are involved in glycolysis, the conversion of sugars into high energy molecules, especially adenosine triphosphate (ATP). The two most abundant myofibrillar proteins, myosin and actin, form the muscle's overall structure and enable it to deliver power, consuming ATP in the process. The remaining protein mass includes connective tissue (collagen and elastin). Fat in meat can be either adipose tissue, used by the animal to store energy and consisting of "true fats" (esters of glycerol with fatty acids), or intramuscular fat, which contains phospholipids and cholesterol. Meat can be broadly classified as "red" or "white" depending on the concentration of myoglobin in muscle fiber. When myoglobin is exposed to oxygen, reddish oxymyoglobin develops, making myoglobin rich meat appear red. The redness of meat depends on species, animal age, and fiber type: Red meat contains more narrow muscle fibers that tend to operate over long periods without rest, while white meat contains more broad fibers that tend to work in short fast bursts, such as the brief flight of the chicken. The meat of adult mammals such as cows, sheep, and horses is considered red, while chicken and turkey breast meat is considered white.

Muscle tissue is high in protein, containing all of the essential amino acids, and in most cases is a good source of zinc, vitamin B12, selenium, phosphorus, niacin, vitamin B6, choline, riboflavin and iron. Several forms of meat are high in vitamin K. Muscle tissue is very low in carbohydrates and does not contain dietary fiber. The fat content of meat varies widely with the species and breed of animal, the way in which the animal was raised, what it was fed, the part of the body, and the methods of butchering and cooking. Wild animals such as deer are leaner than farm animals, leading those concerned about fat content to choose game such as venison. Decades of breeding meat animals for fatness is being reversed by consumer demand for leaner meat. The fatty deposits near the muscle fibers in meats soften meat when it is cooked, improve its flavor, and make the meat seem juicier. Fat around meat further contains cholesterol. The increase in meat consumption after 1960 is associated with significant imbalances of fat and cholesterol in the human diet. + Nutritional content of ; data vary widely with selection (e. g. skinless, boneless) and preparation Source Energy: kJ (kcal) Protein Carbs Fat Chicken breast25 g0 g2 g Lamb mince19 g0 g26 g Beef mince19 g0 g22 g Dog20 g0 g22 g Horse23 g0 g5 g Pork loin14 g0 g30 g Rabbit32 g0 g9 g

Meat can be cooked in many ways, including braising, broiling, frying, grilling, and roasting. Meat can be cured by smoking, which preserves and flavors food by exposing it to smoke from burning or smoldering wood. Other methods of curing include pickling, salting, and air drying. Some recipes call for raw meat; steak tartare is made from minced raw beef. Pâtés are made with ground meat and fat, often including liver.

Meat, in particular red and processed meat, is linked to a variety of health risks.

Toxic compounds including heavy metals, mycotoxins, pesticide residues, dioxins, polychlorinated biphenyl can contaminate meat. Processed, smoked and cooked meat may contain carcinogens such as polycyclic aromatic hydrocarbons.

The consumption of processed and red meat carries an increased risk of cancer. The International Agency for Research on Cancer (IARC), a specialized agency of the World Health Organization (WHO), classified processed meat (e. g., bacon, ham, hot dogs, sausages) as, "carcinogenic to humans (Group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer." IARC classified red meat as "probably carcinogenic to humans (Group 2A), based on limited evidence that the consumption of red meat causes cancer in humans and strong mechanistic evidence supporting a carcinogenic effect." Cancer Research UK, National Health Service (NHS) and the National Cancer Institute have stated that red and processed meat intake increases risk of bowel cancer. The American Cancer Society in their "Diet and Physical Activity Guideline", stated "evidence that red and processed meats increase cancer risk has existed for decades, and many health organizations recommend limiting or avoiding these foods." The Canadian Cancer Society have stated that "eating red and processed meat increases cancer risk". A 2021 review found an increase of 11–51% risk of multiple cancer per 100g/d increment of red meat, and an increase of 8–72% risk of multiple cancer per 50g/d increment of processed meat. Cooking muscle meat creates heterocyclic amines (HCAs), which are thought to increase cancer risk in humans. Researchers at the National Cancer Institute published results of a study which found that human subjects who ate beef rare or medium rare had less than one third the risk of stomach cancer than those who ate beef medium well or well done. While eating muscle meat raw may be the only way to avoid HCAs fully, the National Cancer Institute states that cooking meat below creates "negligible amounts" of HCAs. Microwaving meat before cooking may reduce HCAs by 90%. Nitrosamines, present in processed and cooked foods, are carcinogenic, being linked to colon cancer. Polycyclic aromatic hydrocarbons, present in processed, smoked and cooked foods, are similarly carcinogenic.

Bacterial contamination has been seen with meat products. A 2011 study by the Translational Genomics Research Institute showed that nearly half (47%) of the meat and poultry in U. S. grocery stores were contaminated with S. aureus, with more than half (52%) of those bacteria resistant to antibiotics. A 2018 investigation by the Bureau of Investigative Journalism and The Guardian found that around 15 percent of the US population suffers from foodborne illnesses every year. The investigation highlighted unsanitary conditions in US based meat plants, which included meat products covered in excrement and abscesses "filled with pus". Complete cooking and the careful avoidance of recontamination reduce the risk of bacterial infections from meat.

Consumption of 100 g/day of red meat and 50 g/day of processed meat is associated with an increased risk of diabetes. Diabetes UK advises people to limit their intake of red and processed meat.

Meat production and trade substantially increase risks for infectious diseases (zoonosis), including of pandemics, whether though contact with wild and farmed animals, or via husbandry's environmental impact. For example, avian influenza from poultry meat production is a threat to human health. Furthermore, the use of antibiotics in meat production contributes to antimicrobial resistance – which contributes to millions of deaths – and makes it harder to control infectious diseases.

In response to changing meat prices as well as health concerns about saturated fat and cholesterol, consumers have altered their consumption of various meats. Consumption of beef in the United States between 1970 and 1974 and 1990–1994 dropped by 21%, while consumption of chicken increased by 90%.

Except for poultry, at 50 g/day unprocessed red and processed meat are risk factors for ischemic heart disease, increasing the risk by about 9 and 18% respectively.

A multitude of serious negative environmental effects are associated with meat production. Among these are greenhouse gas emissions, fossil energy use, water use, water quality changes, and effects on grazed ecosystems. They are so significant that according to University of Oxford researchers, "a vegan diet is probably the single biggest way to reduce your impact on planet Earth far bigger than cutting down on your flights or buying an electric car". However, this is often ignored in the public consciousness and in plans to tackle serious environmental issues such as the climate crisis. The livestock sector may be the largest source of water pollution (due to animal wastes, fertilizers, pesticides), and it contributes to emergence of antibiotic resistance. It accounts for over 8% of global human water use. It is a significant driver of biodiversity loss and ecosystems, as it causes deforestation, ocean dead zones, species extinction, land degradation, pollution, overfishing and global warming. Cattle farming was estimated to be responsible for 80 per cent of Amazon deforestation in 2008 due to the clearing of forests to grow animal feed (especially soya) and cattle ranching. Environmental effects vary among livestock production systems. Grazing of livestock can be beneficial for some wildlife species, but not for others. Targeted grazing of livestock is used as a food producing alternative to herbicide use in some vegetation management.

Meat production is by far the biggest user of land, as it accounts for nearly 40% of the global land surface. Just in the contiguous United States, 34% of its land area (654 million acres (264,664,644 km2)) are used as pasture and rangeland, mostly feeding livestock, not counting 391 million acres (158,232,226 km2) of cropland (20%), some of which is used for producing feed for livestock. Roughly 75% of deforested land around the globe is used for livestock pasture. Deforestation from practices like slash and burn releases and removes the carbon sink of grown tropical forest ecosystems which substantially mitigate climate change. Land use is a major pressure on pressure on fertile soils which is important for global food security.

The rising global consumption of carbon intensive meat products has "exploded the global carbon footprint of agriculture," according to some top scientists. Meat production is responsible for some 35% of global emissions of greenhouse gases, and 60% of the greenhouse gases attributable to food production. Some nations show very different impacts to counterparts within the same group, with Brazil and Australia having emissions over 200% higher than the average of their respective income groups, driven by meat consumption. According to the Assessing the Environmental Impacts of Consumption and Production report produced by United Nations Environment Programme's (UNEP) international panel for sustainable resource management, a worldwide transition in the direction of a meat and dairy free diet is indispensable if adverse global climate change were to be prevented. A 2019 report in The Lancet recommended that global meat (and sugar) consumption be reduced by 50 percent to mitigate climate change. Meat consumption in Western societies needs to be reduced by up to 90% according to a 2018 study published in Nature. The 2019 special report by the Intergovernmental Panel on Climate Change called for significantly reducing meat consumption, particularly in wealthy countries, in order to mitigate and adapt to climate change.

Meat consumption is a primary contributor to the sixth mass extinction. A 2017 study by the World Wildlife Fund found that 60% of global biodiversity loss is attributable to meat based diets, in particular from the use of land for feed crops, resulting in large scale loss of habitats and species. Livestock make up 60% of the biomass of all mammals on earth, followed by humans (36%) and wild mammals (4%). In November 2017, 15,364 world scientists signed a Warning to Humanity calling for a drastic reduction in per capita consumption of meat and "dietary shifts towards mostly plant based foods". The 2019 Global Assessment Report on Biodiversity and Ecosystem Services recommended a reduction in meat consumption to mitigate biodiversity loss. A 2021 Chatham House report asserted that a shift towards plant based diets would free up land for the restoration of ecosystems and biodiversity. Meat consumption is predicted to rise as the human population increases and becomes more affluent; this in turn would increase greenhouse gas emissions and further reduce biodiversity.

The environmental impact of meat production can be reduced on the farm by conversion of human inedible residues of food crops. Manure from meat producing livestock is used as fertilizer; it may be composted before application to food crops. Substitution of animal manures for synthetic fertilizers in crop production can be environmentally significant, as between 43 and 88 MJ of fossil fuel energy are used per kg of nitrogen in manufacture of synthetic nitrogenous fertilizers.

The IPCC and others have stated that meat production has to be reduced substantially for any sufficient mitigation of climate change and, at least initially, largely through shifts towards plant based diets where meat consumption is high. cultured meat, microbial foods, mycoprotein, meat substitutes, and other alternatives, such as those based on mushrooms, legumes (pulses), and other food sources. Land previously used for meat production can be rewilded.

Meat is part of the human diet in most cultures, where it often has symbolic meaning and important social functions.

Ethical issues regarding the consumption of meat include objecting to the act of killing animals or to the agricultural practices used in meat production. Reasons for objecting to killing animals for consumption may include animal rights, environmental ethics, or an aversion to inflicting pain or harm on sentient animals. Some people, while not vegetarians, refuse to eat the flesh of certain animals for cultural or religious reasons. The founders of Western philosophy disagreed about the ethics of eating meat. Plato's Republic has Socrates describe the ideal state as vegetarian. Pythagoras believed that humans and animals were equal and therefore disapproved of meat consumption, as did Plutarch, whereas Zeno and Epicurus were vegetarian but allowed meat eating in their philosophy. exist to serve humans, including as food. Jewish Kashrut dietary rules allow certain kosher meats and forbid others (treif). The rules prohibit the consumption of unclean animals such as pork, and mixtures of meat and milk. Similar rules apply in Islamic dietary laws: The Quran explicitly forbids meat from animals that die naturally, blood, and the meat of pigs, which are haram, forbidden, as opposed to halal, allowed. Some Sikh groups oppose eating any meat.

Research in applied psychology has investigated meat eating in relation to morality, emotions, cognition, and personality. Psychological research suggests meat eating is correlated with masculinity, and reduced openness to experience. Research into the consumer psychology of meat is relevant both to meat industry marketing and to those advocating eating less meat.

Unlike most other foods, meat is not perceived as gender neutral: it is associated with men and masculinity. Sociological research, ranging from African tribal societies to contemporary barbecues, indicates that men are much more likely to participate in preparing meat than other food. This has been attributed to the influence of traditional male gender roles, in view of what Jack Goody calls a "male familiarity with killing", or as Claude Lévi Strauss suggests, that roasting is more violent than boiling. By and large, at least in modern societies, men tend to consume more meat than women, and men often prefer red meat whereas women tend to prefer chicken and fish.