
Meat is animal
tissue, often
muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
, that is eaten as food. Humans have hunted and farmed other animals for meat since prehistory. The
Neolithic Revolution allowed the
domestication of vertebrates, including
chicken
The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...
s,
sheep,
goat
The goat or domestic goat (''Capra hircus'') is a species of Caprinae, goat-antelope that is mostly kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the ...
s,
pigs,
horse
The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...
s, 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, health, and nutritional status of the animal involved. Without preservation, bacteria and fungi decompose and
spoil unprocessed meat within hours or days. Meat is
edible raw, but it is mostly eaten cooked, such as by
stewing or
roasting, or
processed, such as by
smoking
Smoking is a practice in which a substance is combusted, and the resulting smoke is typically inhaled to be tasted and absorbed into the bloodstream of a person. Most commonly, the substance used is the dried leaves of the tobacco plant, whi ...
or
salting.
The consumption of meat (especially
red and processed meat, as opposed to
fish
A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...
and
poultry
Poultry () are domesticated birds kept by humans for the purpose of harvesting animal products such as meat, Eggs as food, eggs or feathers. The practice of animal husbandry, raising poultry is known as poultry farming. These birds are most typ ...
) increases the risk of certain negative health outcomes including cancer,
coronary heart disease, and
diabetes. Meat production is a major contributor to
environmental issues including
global warming
Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...
, pollution, and
biodiversity loss, at local and global scales, but meat is important to economies and cultures around the world. Some people (
vegetarians and
vegans) choose not to eat meat for
ethical
Ethics is the philosophical study of moral phenomena. Also called moral philosophy, it investigates normative questions about what people ought to do or which behavior is morally right. Its main branches include normative ethics, applied e ...
, environmental, health or religious reasons.
Etymology
The word ''meat'' comes from the
Old English
Old English ( or , or ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the Early Middle Ages. It developed from the languages brought to Great Britain by Anglo-S ...
word , meaning food in general. In modern usage, ''meat'' primarily means
skeletal muscle
Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous system, voluntary muscular system and typically are a ...
with its associated fat and connective tissue, but it can include
offal, other edible organs such as
liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...
and
kidney
In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...
. The term is sometimes used in a more restrictive sense to mean the flesh of
mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
ian species (pigs, cattle, sheep, goats, etc.) raised and prepared for human consumption, to the exclusion of
fish
A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...
, other seafood,
insects
Insects (from Latin ') are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed ...
, poultry, or other animals.
History
Domestication
Paleontological evidence suggests that meat constituted a substantial proportion of the diet of the earliest humans. Early
hunter-gatherer
A hunter-gatherer or forager is a human living in a community, or according to an ancestrally derived Lifestyle, lifestyle, in which most or all food is obtained by foraging, that is, by gathering food from local naturally occurring sources, esp ...
s depended on the organized hunting of large animals such as
bison
A bison (: bison) is a large bovine in the genus ''Bison'' (from Greek, meaning 'wild ox') within the tribe Bovini. Two extant taxon, extant and numerous extinction, extinct species are recognised.
Of the two surviving species, the American ...
and
deer. Animals were
domesticated in the
Neolithic
The Neolithic or New Stone Age (from Ancient Greek, Greek 'new' and 'stone') is an archaeological period, the final division of the Stone Age in Mesopotamia, Asia, Europe and Africa (c. 10,000 BCE to c. 2,000 BCE). It saw the Neolithic Revo ...
, enabling the systematic production of meat and the
breeding of animals to improve meat production.
Intensive animal farming
In the
postwar period
A post-war or postwar period is the interval immediately following the end of a war. The term usually refers to a varying period of time after World War II, which ended in 1945. A post-war period can become an interwar period or interbellum, w ...
, 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.
Intensive animal farming became globalized in the later years of the 20th century, replacing traditional stock rearing in countries around the world.
In 1990 intensive animal farming accounted for 30% of world meat production and by 2005, this had risen to 40%.
Selective breeding
Modern agriculture employs techniques such as
progeny testing to speed
selective breeding, allowing the rapid acquisition of the qualities desired by meat producers. For instance, in the wake of well-publicized health concerns associated with
saturated fats in the 1980s, the fat content of United Kingdom beef, pork and lamb fell from 20–26 percent to 4–8 percent within a few decades, due to both selective breeding for leanness and changed methods of butchery. Methods of
genetic engineering
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of Genetic engineering techniques, technologies used to change the genet ...
that could improve the meat-producing qualities of animals are becoming available.
Meat production continues to be shaped by the demands of customers. The trend towards selling meat in pre-packaged cuts has increased the demand for larger breeds of cattle, better suited to producing such cuts. Animals not previously exploited for their meat are now being farmed, including mammals such as
antelope
The term antelope refers to numerous extant or recently extinct species of the ruminant artiodactyl family Bovidae that are indigenous to most of Africa, India, the Middle East, Central Asia, and a small area of Eastern Europe. Antelopes do ...
, zebra,
water buffalo and camel, as well as non-mammals, such as crocodile,
emu
The emu (; ''Dromaius novaehollandiae'') is a species of flightless bird endemism, endemic to Australia, where it is the Tallest extant birds, tallest native bird. It is the only extant taxon, extant member of the genus ''Dromaius'' and the ...
and ostrich.
Organic farming supports an increasing demand for meat produced to that standard.
File:Lamb meat.jpg, A shoulder of lamb
File:Hereford bull large.jpg, A Hereford
Hereford ( ) is a cathedral city and the county town of the ceremonial county of Herefordshire, England. It is on the banks of the River Wye and lies east of the border with Wales, north-west of Gloucester and south-west of Worcester. With ...
bull, a breed of beef cattle
File:SelectionOfPackageMeats.jpg, Supermarket meat, North America
Animal growth and development
Several factors affect the growth and development of meat.
Genetics
Some economically important traits in meat animals are heritable to some degree, and can thus be selected for by
animal breeding
Animal breeding is a branch of animal science that addresses the evaluation (using best linear unbiased prediction and other methods) of the genetic value (estimated breeding value, EBV) of livestock. Selecting for breeding animals with superior ...
. In cattle, certain growth features are controlled by
recessive genes which have not so far been excluded, complicating breeding. One such trait is
dwarfism; another is the doppelender or "
double muscling" condition, which causes
muscle hypertrophy and thereby increases the animal's commercial value.
Genetic analysis continues to reveal the mechanisms that control numerous aspects of the
endocrine system
The endocrine system is a messenger system in an organism comprising feedback loops of hormones that are released by internal glands directly into the circulatory system and that target and regulate distant Organ (biology), organs. In vertebrat ...
and, through it, meat growth and quality.
Genetic engineering
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of Genetic engineering techniques, technologies used to change the genet ...
can shorten breeding programs significantly because they allow for the identification and isolation of
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
s coding for desired traits, and for the reincorporation of these genes into the animal
genome
A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...
. To enable this, the genomes of many animals
are being mapped. Some research has already seen commercial application. For instance, a
recombinant bacterium has been developed which improves the digestion of grass in the
rumen
The rumen, also known as a paunch, is the largest stomach compartment in ruminants. The rumen and the reticulum make up the reticulorumen in ruminant animals. The diverse microbial communities in the rumen allows it to serve as the primary si ...
of cattle, and some features of muscle fibers have been genetically altered. Experimental
reproductive cloning of commercially important meat animals such as sheep, pig or cattle has been successful. Asexual reproduction of animals bearing desirable traits is anticipated.
Environment
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 field
A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...
s, for reasons still unknown, retard animal development.
Animal nutrition
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.
Ruminant
Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...
s, which may digest
cellulose
Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important s ...
, 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 acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...
s during their passage through the
rumen
The rumen, also known as a paunch, is the largest stomach compartment in ruminants. The rumen and the reticulum make up the reticulorumen in ruminant animals. The diverse microbial communities in the rumen allows it to serve as the primary si ...
, the recycling of
manure by feeding it back to cattle mixed with feed concentrates, or the conversion of petroleum
hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and Hydrophobe, hydrophobic; their odor is usually fain ...
s to protein through microbial action.
In plant feed, environmental factors influence the availability of crucial
nutrient
A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...
s or
micronutrients, a lack or excess of which can cause a great many ailments. In Australia, where the soil contains limited
phosphate
Phosphates are the naturally occurring form of the element phosphorus.
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...
, 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
toxin
A toxin is a naturally occurring poison produced by metabolic activities of living cells or organisms. They occur especially as proteins, often conjugated. The term was first used by organic chemist Ludwig Brieger (1849–1919), derived ...
s 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
Methylmercury is an organometallic cation with the formula . It is the simplest organomercury compound. Methylmercury is extremely toxic, and its derivatives are the major source of organic mercury for humans. It is a bioaccumulative environment ...
and some
pesticide
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others (see table). The most common of these are herbicides, which account for approximately 50% of all p ...
residues present a particular hazard as they
bioaccumulate in meat, potentially poisoning consumers.
Animal welfare

Practices such as confinement in
factory farming have generated concerns for
animal welfare
Animal welfare is the quality of life and overall well-being of animals. Formal standards of animal welfare vary between contexts, but are debated mostly by animal welfare groups, legislators, and academics. Animal welfare science uses measures ...
. Animals have
abnormal behaviors such as tail-biting, cannibalism, and
feather pecking.
Invasive procedures such as
beak trimming,
castration
Castration is any action, surgery, surgical, chemical substance, chemical, or otherwise, by which a male loses use of the testicles: the male gonad. Surgical castration is bilateral orchiectomy (excision of both testicles), while chemical cas ...
, 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.
Human intervention
Meat producers may seek to improve the
fertility of female animals through the administration of
gonadotrophic or
ovulation-inducing
hormone
A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...
s. 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
Artificial insemination is the deliberate introduction of sperm into a female's cervix or uterine cavity for the purpose of achieving a pregnancy through in vivo fertilization by means other than sexual intercourse. It is a fertility treatment ...
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
steroid
A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration.
Steroids have two principal biological functions: as important components of cell membranes t ...
s, 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
Castration is any action, surgery, surgical, chemical substance, chemical, or otherwise, by which a male loses use of the testicles: the male gonad. Surgical castration is bilateral orchiectomy (excision of both testicles), while chemical cas ...
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
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...
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
Antimicrobial resistance (AMR or AR) occurs when microbes evolve mechanisms that protect them from antimicrobials, which are drugs used to treat infections. This resistance affects all classes of microbes, including bacteria (antibiotic resista ...
in
pathogen
In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...
ic microorganisms.
Composition
Biochemical
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
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
consists of roughly 75 percent water, 19 percent protein, 2.5 percent intramuscular fat, 1.2 percent
carbohydrate
A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ...
s and 2.3 percent other soluble substances. These include organic compounds, especially
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...
s, 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 (
myofibril
A myofibril (also known as a muscle fibril or sarcostyle) is a basic rod-like organelle of a muscle cell. Skeletal muscles are composed of long, tubular cells known as Skeletal muscle#Skeletal muscle cells, muscle fibers, and these cells contain ...
lar proteins, about 5.5 percent of mass). There are several hundred sarcoplasmic proteins. Most of them – the glycolytic
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
s – are involved in
glycolysis, the conversion of sugars into high-energy molecules, especially
adenosine triphosphate
Adenosine triphosphate (ATP) is a nucleoside triphosphate that provides energy to drive and support many processes in living cell (biology), cells, such as muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all known ...
(ATP). The two most abundant myofibrillar proteins,
myosin and
actin
Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of ...
, 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
Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a trip ...
and
elastin
Elastin is a protein encoded by the ''ELN'' gene in humans and several other animals. Elastin is a key component in the extracellular matrix of gnathostomes (jawed vertebrates). It is highly Elasticity (physics), elastic and present in connective ...
). Fat in meat can be either
adipose tissue, used by the animal to store energy and consisting of "true fats" (
ester
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...
s of
glycerol
Glycerol () is a simple triol compound. It is a colorless, odorless, sweet-tasting, viscous liquid. The glycerol backbone is found in lipids known as glycerides. It is also widely used as a sweetener in the food industry and as a humectant in pha ...
with
fatty acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an ...
s), or intramuscular fat, which contains
phospholipid
Phospholipids are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typ ...
s and
cholesterol
Cholesterol is the principal sterol of all higher animals, distributed in body Tissue (biology), tissues, especially the brain and spinal cord, and in Animal fat, animal fats and oils.
Cholesterol is biosynthesis, biosynthesized by all anima ...
.
Meat can be broadly classified as "red" or "white" depending on the concentration of
myoglobin
Myoglobin (symbol Mb or MB) is an iron- and oxygen-binding protein found in the cardiac and skeletal muscle, skeletal Muscle, muscle tissue of vertebrates in general and in almost all mammals. Myoglobin is distantly related to hemoglobin. Compar ...
in muscle fiber. When myoglobin is exposed to
oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...
, 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
The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...
and
turkey
Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...
breast meat is considered white.
File:Blade steak (cropped).jpg, "Red" meat:
beef steak
File:Hühnerbrustfilet 20090502 001 (cropped).JPG, "White" meat:
chicken breast (flight muscle)
Nutritional
Muscle
Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...
tissue is high in protein, containing all of the
essential amino acids, and in most cases is a good source of
zinc
Zinc is a chemical element; it has symbol Zn and atomic number 30. It is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic tabl ...
,
vitamin B12,
selenium
Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...
,
phosphorus
Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...
,
niacin,
vitamin B6,
choline,
riboflavin
Riboflavin, also known as vitamin B2, is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in ...
and iron.
Several forms of meat are high in
vitamin K
Vitamin K is a family of structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-translational modification, post-synthesis modification of certain proteins ...
.
Muscle tissue is very low in carbohydrates and does not contain dietary fiber.
The fat content of meat varies widely with the
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
and
breed
A breed is a specific group of breedable domestic animals having homogeneous appearance (phenotype), homogeneous behavior, and/or other characteristics that distinguish it from other organisms of the same species. In literature, there exist seve ...
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
A game is a structured type of play usually undertaken for entertainment or fun, and sometimes used as an educational tool. Many games are also considered to be work (such as professional players of spectator sports or video games) or art ...
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
Cholesterol is the principal sterol of all higher animals, distributed in body Tissue (biology), tissues, especially the brain and spinal cord, and in Animal fat, animal fats and oils.
Cholesterol is biosynthesis, biosynthesized by all anima ...
. The increase in meat consumption after 1960 is associated with significant imbalances of fat and cholesterol in the human diet.
Production
File:World production of meat, main items.svg, World production of meat, main items
File:World production of main meat items, main producers (2019).svg, World production of main meat items, main producers (2019)
Transport
Upon reaching a predetermined age or weight, livestock are usually transported ''en masse'' to the slaughterhouse. Depending on its length and circumstances, this may exert stress and injuries on the animals, and some may die ''en route''. Unnecessary stress in transport may adversely affect the quality of the meat. In particular, the muscles of stressed animals are low in water and
glycogen, and their
pH fails to attain acidic values, all of which results in poor meat quality.
Slaughter
Animals are usually slaughtered by being first
stunned and then
exsanguinated (bled out). Death results from the one or the other procedure, depending on the methods employed. Stunning can be effected through
asphyxiating the animals with
carbon dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...
, shooting them with a gun or a
captive bolt pistol, or shocking them with electric current. The exsanguination is accomplished by severing the
carotid artery and the
jugular vein in cattle and sheep, and the
anterior vena cava in pigs. Draining as much blood as possible from the carcass is necessary because blood causes the meat to have an unappealing appearance and is a breeding ground for microorganisms.
Dressing and cutting
After exsanguination, the carcass is dressed; that is, the head, feet, hide (except hogs and some veal), excess fat,
viscera and
offal are removed, leaving only bones and edible muscle. Cattle and pig carcases, but not those of sheep, are then split in half along the mid ventral axis, and the carcase is cut into wholesale pieces. The dressing and cutting sequence, long a province of manual labor, is being progressively automated.
Conditioning
Under hygienic conditions and without other treatment, meat can be stored at above its freezing point (−1.5 °C) for about six weeks without spoilage, during which time it undergoes an aging process that increases its tenderness and flavor. During the first day after death,
glycolysis continues until the accumulation of
lactic acid causes the
pH to reach about 5.5. The remaining
glycogen, about 18 g per kg, increases the water-holding capacity and tenderness of cooked meat.
''
Rigor mortis'' sets in a few hours after death as
adenosine triphosphate
Adenosine triphosphate (ATP) is a nucleoside triphosphate that provides energy to drive and support many processes in living cell (biology), cells, such as muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all known ...
is used up. This causes the muscle proteins
actin
Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of ...
and
myosin to combine into rigid
actomyosin. This in turn lowers the meat's water-holding capacity, so the meat loses water or "weeps". In muscles that enter ''rigor'' in a contracted position, actin and myosin filaments overlap and cross-bond, resulting in meat that becomes tough when cooked. Over time, muscle proteins
denature in varying degree, with the exception of the collagen and
elastin
Elastin is a protein encoded by the ''ELN'' gene in humans and several other animals. Elastin is a key component in the extracellular matrix of gnathostomes (jawed vertebrates). It is highly Elasticity (physics), elastic and present in connective ...
of
connective tissue, and ''rigor mortis'' resolves. These changes mean that meat is tender and pliable when cooked just after death or after the resolution of ''rigor'', but tough when cooked during ''rigor.''
As the muscle pigment
myoglobin
Myoglobin (symbol Mb or MB) is an iron- and oxygen-binding protein found in the cardiac and skeletal muscle, skeletal Muscle, muscle tissue of vertebrates in general and in almost all mammals. Myoglobin is distantly related to hemoglobin. Compar ...
denatures, its iron
oxidizes, which may cause a brown discoloration near the surface of the meat. Ongoing
proteolysis contributes to conditioning:
hypoxanthine, a breakdown product of ATP, contributes to meat's flavor and odor, as do other products of the decomposition of muscle fat and protein.
File:Atria slaughterhouse in Nurmo Seinajoki.JPG, A slaughterhouse, Finland
File:MIN Rungis viandes de boucherie veau.jpg, Rungis International Market, France
File:Sucuk-1.jpg, The word "sausage
A sausage is a type of meat product usually made from ground meat—often pork, beef, or poultry—along with salt, spices and other flavourings. Other ingredients, such as grains or breadcrumbs, may be included as fillers or extenders.
...
" is derived from Old French
Old French (, , ; ) was the language spoken in most of the northern half of France approximately between the late 8th , from -4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ...
.
(specifically, isotopic analysis">Bioarchaeology">bioarchaeological (specifically, isotopic analysis) study of early medieval England found, based on the funerary record, that high-meat protein diets were extremely rare, and that (contrary to previously held assumptions) elites did not consume more meat than non-elites, and men did not consume more meat than women.
In the nineteenth century, meat consumption in Britain was the highest in Europe, exceeded only by that in British colonies. In the 1830s consumption per head in Britain was about a year, rising to in 1912. In 1904, laborers consumed a year while aristocrats ate . There were some 43,000 butcher's shops in Britain in 1910, with "possibly more money invested in the meat industry than in any other British business" except finance.
The US was a meat importing country by 1926.
Truncated lifespan as a result of intensive breeding allows more meat to be produced from fewer animals. The world cattle population was about 600 million in 1929, with 700 million sheep and goats and 300 million pigs.
has increased from the 20th to the 21st centuries. Poultry meat has increased by 76.6% per kilo per capita and pig meat by 19.7%. Bovine meat has decreased from per capita in 1990 to per capita in 2009. FAO analysis found that 357 million tonnes of meat were produced in 2021, 53% more than in 2000, with chicken meat representing more than half the increase.
Overall, diets that include meat are the most common worldwide according to the results of a 2018
study of 16–64 years olds in 28 countries. Ipsos states "An omnivorous diet is the most common diet globally, with non-meat diets (which can include fish) followed by over a tenth of the global population." Approximately 87% of people include meat in their diet in some frequency. 73% of meat eaters included it in their diet regularly and 14% consumed meat only occasionally or infrequently.
The type of meat consumed varies between different cultures. The amount and kind of meat consumed varies by income, both between countries and within a given country.
are commonly eaten in countries such as France, Italy, Germany and Japan. Horses and other large
in western Europe.
are consumed in China, South Korea and Vietnam. Dogs are occasionally eaten in the
regions. Historically, dog meat has been consumed in various parts of the world, such as Hawaii,
and Mexico.
are sometimes eaten, such as in Peru.
.
s are hunted, partly for their flesh, in several countries. Misidentification is a risk; in 2013, products in Europe labelled as beef
. Meat can be
, which preserves and flavors food by exposing it to smoke from burning or smoldering wood. Other methods of curing include
, and air-drying. Some recipes call for raw meat;
is made from minced raw beef.
Meat, in particular red and processed meat, is linked to a variety of health risks.
'' asked men and teenage boys to increase their consumption of vegetables or other underconsumed foods (fruits, whole grains, and dairy) while reducing intake of protein foods (meats, poultry, and eggs) that they currently overconsume.
can contaminate meat. Processed, smoked and cooked meat may contain
.