Milk

Milk

Overview


Milk is a white liquid produced by the mammary gland
Mammary gland
A mammary gland is an organ in mammals that produces milk to feed young offspring. Mammals get their name from the word "mammary". In ruminants such as cows, goats, and deer, the mammary glands are contained in their udders...

s of mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s. It is the primary source of nutrition
Nutrition
Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....

 for young mammals before they are able to digest
Digestion
Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....

 other types of food. Early-lactation
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...

 milk contains colostrum
Colostrum
Colostrum is a form of milk produced by the mammary glands of mammals in late pregnancy. Most species will generate colostrum just prior to giving birth...

, which carries the mother's antibodies
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...

 to the baby and can reduce the risk of many diseases in the baby.

Milk derived from cattle species is an important food. It has many nutrients. The precise nutrient composition of raw milk
Raw milk
Raw milk is milk that has not been pasteurized or homogenized.-History:Humans consumed raw milk exclusively prior to the industrial revolution and the invention of the pasteurization process in 1864. During the industrial revolution large populations congregated into urban areas detached from the...

 vary by species and by a number of other factors, but it contains significant amounts of saturated fat
Saturated fat
Saturated fat is fat that consists of triglycerides containing only saturated fatty acids. Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain. That is, the chain of carbon atoms is fully "saturated" with hydrogen atoms...

, protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 and calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

 as well as vitamin C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...

.
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Encyclopedia


Milk is a white liquid produced by the mammary gland
Mammary gland
A mammary gland is an organ in mammals that produces milk to feed young offspring. Mammals get their name from the word "mammary". In ruminants such as cows, goats, and deer, the mammary glands are contained in their udders...

s of mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

s. It is the primary source of nutrition
Nutrition
Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....

 for young mammals before they are able to digest
Digestion
Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed into a blood stream, for instance. Digestion is a form of catabolism: a breakdown of large food molecules to smaller ones....

 other types of food. Early-lactation
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...

 milk contains colostrum
Colostrum
Colostrum is a form of milk produced by the mammary glands of mammals in late pregnancy. Most species will generate colostrum just prior to giving birth...

, which carries the mother's antibodies
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...

 to the baby and can reduce the risk of many diseases in the baby.

Milk derived from cattle species is an important food. It has many nutrients. The precise nutrient composition of raw milk
Raw milk
Raw milk is milk that has not been pasteurized or homogenized.-History:Humans consumed raw milk exclusively prior to the industrial revolution and the invention of the pasteurization process in 1864. During the industrial revolution large populations congregated into urban areas detached from the...

 vary by species and by a number of other factors, but it contains significant amounts of saturated fat
Saturated fat
Saturated fat is fat that consists of triglycerides containing only saturated fatty acids. Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain. That is, the chain of carbon atoms is fully "saturated" with hydrogen atoms...

, protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 and calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

 as well as vitamin C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...

. Cow's milk has a pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

 ranging from 6.4 to 6.8, making it slightly acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

ic.

Milk is an important food for over 6 billion human beings of all ages, majority of them in developing countries. Over 750 million people live within dairy farming households. World's dairy farms produced over 710 million tons of milk in 2010. India is the world's largest producer and consumer of milk, yet neither exports nor imports milk. New Zealand, EU-15 and Australia are the world's three largest exporters of milk and milk products. China, Mexico and Japan are the world's largest importers of milk and milk products.

Milk is a key contributor to improving nutrition and food security particularly in developing countries. Improvements in livestock, dairy technology and milk quality may offer the most promise in reducing poverty and malnutrition in the world.

Types of consumption


There are two distinct types of milk consumption: a natural source of nutrition for all infant mammals and a food product for humans of all ages that is derived from other animals.

Nutrition for infant mammals




In almost all mammals, milk is fed to infant
Infant
A newborn or baby is the very young offspring of a human or other mammal. A newborn is an infant who is within hours, days, or up to a few weeks from birth. In medical contexts, newborn or neonate refers to an infant in the first 28 days after birth...

s through breastfeeding
Breastfeeding
Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts rather than from a baby bottle or other container. Babies have a sucking reflex that enables them to suck and swallow milk. It is recommended that mothers breastfeed for six months or...

, either directly or by expressing the milk to be stored and consumed later. Some cultures, historically or currently, continue to use breast
Breast
The breast is the upper ventral region of the torso of a primate, in left and right sides, which in a female contains the mammary gland that secretes milk used to feed infants.Both men and women develop breasts from the same embryological tissues...

 milk to feed their children until they are seven years old.

Human infants sometimes are fed fresh goat milk. There are known risks in this practice, including those of developing electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....

 imbalances, metabolic acidosis
Metabolic acidosis
In medicine, metabolic acidosis is a condition that occurs when the body produces too much acid or when the kidneys are not removing enough acid from the body. If unchecked, metabolic acidosis leads to acidemia, i.e., blood pH is low due to increased production of hydrogen by the body or the...

, megaloblastic anemia
Megaloblastic anemia
Megaloblastic anemia is an anemia that results from inhibition of DNA synthesis in red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the G2 growth stage to the mitosis stage...

, and a host of allergic reactions.

Food product for humans


In many cultures of the world, especially the Western world, humans continue to consume milk beyond infancy, using the milk of other animals (especially cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

, goat
Goat
The domestic goat is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of...

s and sheep) as a food product. For millennia, cow's milk has been processed into dairy products such as cream
Cream
Cream is a dairy product that is composed of the higher-butterfat layer skimmed from the top of milk before homogenization. In un-homogenized milk, over time, the lighter fat rises to the top. In the industrial production of cream this process is accelerated by using centrifuges called "separators"...

, butter
Butter
Butter is a dairy product made by churning fresh or fermented cream or milk. It is generally used as a spread and a condiment, as well as in cooking applications, such as baking, sauce making, and pan frying...

, yogurt, kefir
Kefir
Kefir is a fermented milk drink that originated with shepherds of the North Caucasus region, who discovered that fresh milk carried in leather pouches would occasionally ferment into an effervescent beverage...

, ice cream
Ice cream
Ice cream is a frozen dessert usually made from dairy products, such as milk and cream, and often combined with fruits or other ingredients and flavours. Most varieties contain sugar, although some are made with other sweeteners...

, and especially the more durable and easily transportable product, cheese
Cheese
Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....

. Modern industrial processes produce casein
Casein
Casein is the name for a family of related phosphoprotein proteins . These proteins are commonly found in mammalian milk, making up 80% of the proteins in cow milk and between 60% and 65% of the proteins in human milk....

, whey protein
Whey protein
Whey protein is a mixture of globular proteins isolated from whey, the liquid material created as a by-product of cheese production. Some preclinical studies in rodents have suggested that whey protein may possess anti-inflammatory or anti-cancer properties; however, human data is lacking...

, lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...

, condensed milk
Condensed milk
Condensed milk, also known as sweetened condensed milk, is cow's milk from which water has been removed and to which sugar has been added, yielding a very thick, sweet product which when canned can last for years without refrigeration if unopened. The two terms, condensed milk and sweetened...

, powdered milk
Powdered milk
Powdered milk is a manufactured dairy product made by evaporating milk to dryness. One purpose of drying milk is to preserve it; milk powder has a far longer shelf life than liquid milk and does not need to be refrigerated, due to its low moisture content. Another purpose is to reduce its bulk for...

, and many other food-additive and industrial products.

Humans are an exception in the natural world for consuming milk past infancy, despite the fact that many humans show some degree (some as little as 5%) of lactose intolerance, a characteristic that is more prevalent among individuals of African or Asian descent. The sugar lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...

 is found only in milk, forsythia
Forsythia
Forsythia is a genus of flowering plants in the family Oleaceae . There are about 11 species, mostly native to eastern Asia, but one native to southeastern Europe. The common name is also Forsythia; the genus is named after William Forsyth.-Growth:They are deciduous shrubs typically growing to a...

 flowers, and a few tropical shrubs. The enzyme needed to digest lactose, lactase
Lactase
Lactase , a part of the β-galactosidase family of enzymes, is a glycoside hydrolase involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers...

, reaches its highest levels in the small intestines after birth and then begins a slow decline unless milk is consumed regularly. On the other hand, those groups who do continue to tolerate milk often have exercised great creativity in using the milk of domesticated
Domestication
Domestication or taming is the process whereby a population of animals or plants, through a process of selection, becomes accustomed to human provision and control. In the Convention on Biological Diversity a domesticated species is defined as a 'species in which the evolutionary process has been...

 ungulate
Ungulate
Ungulates are several groups of mammals, most of which use the tips of their toes, usually hoofed, to sustain their whole body weight while moving. They make up several orders of mammals, of which six to eight survive...

s, not only of cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

, but also sheep, goat
Goat
The domestic goat is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of...

s, yak
Yak
The yak, Bos grunniens or Bos mutus, is a long-haired bovine found throughout the Himalayan region of south Central Asia, the Tibetan Plateau and as far north as Mongolia and Russia. In addition to a large domestic population, there is a small, vulnerable wild yak population...

s, water buffalo
Water buffalo
The water buffalo is a domesticated bovid widely kept in Asia, Europe and South America.Water buffalo can also refer to:*Wild water buffalo , the wild ancestor of the domestic water buffalo...

, horse
Horse
The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

s, reindeer
Reindeer
The reindeer , also known as the caribou in North America, is a deer from the Arctic and Subarctic, including both resident and migratory populations. While overall widespread and numerous, some of its subspecies are rare and one has already gone extinct.Reindeer vary considerably in color and size...

s and camel
Camel
A camel is an even-toed ungulate within the genus Camelus, bearing distinctive fatty deposits known as humps on its back. There are two species of camels: the dromedary or Arabian camel has a single hump, and the bactrian has two humps. Dromedaries are native to the dry desert areas of West Asia,...

s. The largest producer and consumer of cattle and buffalo milk in the world is India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

.
Top ten per capita cow's milk and cow's milk products consumers in 2006
Country Milk (liters) Cheese (kg) Butter (kg)
183.9 19.1 5.3
145.5 18.5 1.0
129.8 10.5 2.9
122.9 20.4 3.3
116.7 16.0 4.3
119.1 9.6 1.0
112.5 22.2 5.6
111.2 12.2 3.7
106.3 11.7 3.7
94.7 12.2 3.3

Price


It was reported in 2007 that with increased worldwide prosperity and the competition of bio-fuel production for feed stocks, both the demand for and the price of milk had substantially increased worldwide. Particularly notable was the rapid increase of consumption of milk in China and the rise of the price of milk in the United States above the government subsidized price. In 2010 the Department of Agriculture
United States Department of Agriculture
The United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...

 predicted farmers would receive an average of $1.35 per US gallon of cow's milk (35 cents per liter), which is down 30 cents per gallon from 2007 and below the break-even
Break-even
Break-even is a point where any difference between plus or minus or equivalent changes side.-In economics:A technique for which identifying the point where the total revenue is just sufficient to cover the total cost...

 point for many cattle farmers.

Terminology


The term milk is also used for white colored, non-animal beverages resembling milk in color and texture such as soy milk
Soy milk
Soy milk and sometimes referred to as soy drink/beverage is a beverage made from soybeans. A stable emulsion of oil, water, and protein, it is produced by soaking dry soybeans and grinding them with water...

, rice milk
Rice milk
Rice milk is a kind of grain milk processed from rice. It is mostly made from brown rice and commonly unsweetened. The sweetness in most rice milk varieties is generated by a natural enzymatic process, cleaving the carbohydrates into sugars, especially glucose, similar to the Japanese amazake...

, almond milk
Almond milk
Almond milk is a milky drink made from ground almonds. Unlike animal milk, almond milk contains no cholesterol or lactose. Regular, unsweetened almond milk can be used as a substitute for animal milk in many recipes, and as it does not contain any animal products, is suitable for vegetarians and...

, and coconut milk
Coconut milk
Coconut milk is the water that comes from the grated meat of a coconut. The colour and rich taste of the milk can be attributed to the high oil content. In many parts of the world, the term coconut milk is also used to refer to coconut water, the naturally occurring liquid found inside the hollow...

. In addition, a substance secreted by pigeons to feed their young is called crop milk
Crop milk
Crop milk is a secretion from the lining of the crop of parent birds that is regurgitated to young birds. They are found among all pigeons and doves where they are referred to as pigeon milk...

 and bears some resemblance to mammalian milk. Dairy relates to milk and milk production, eg. dairy products.

Evolution of lactation



The mammary gland
Mammary gland
A mammary gland is an organ in mammals that produces milk to feed young offspring. Mammals get their name from the word "mammary". In ruminants such as cows, goats, and deer, the mammary glands are contained in their udders...

 is thought to have been derived from apocrine skin glands. It has been suggested that the original function of lactation
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...

 (milk production) was keeping eggs moist. Much of the argument is based on monotreme
Monotreme
Monotremes are mammals that lay eggs instead of giving birth to live young like marsupials and placental mammals...

s (egg-laying mammals): The original adaptive significance of milk secretions may have been nutrition or immunological protection. This secretion gradually became more copious and accrued nutritional complexity over evolutionary time.

History



Humans first learned to regularly consume the milk of other mammals following the domestication
Domestication
Domestication or taming is the process whereby a population of animals or plants, through a process of selection, becomes accustomed to human provision and control. In the Convention on Biological Diversity a domesticated species is defined as a 'species in which the evolutionary process has been...

 of animals during the Neolithic Revolution
Neolithic Revolution
The Neolithic Revolution was the first agricultural revolution. It was the transition from hunting and gathering to agriculture and settlement. Archaeological data indicates that various forms of plants and animal domestication evolved independently in 6 separate locations worldwide circa...

 or the invention of agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

. This development occurred independently in several places around the world from as early as 9000–7000 BC in Southwest Asia
Southwest Asia
Western Asia, West Asia, Southwest Asia or Southwestern Asia are terms that describe the westernmost portion of Asia. The terms are partly coterminous with the Middle East, which describes a geographical position in relation to Western Europe rather than its location within Asia...

 to 3500–3000 BC in the Americas. The most important dairy animals—cattle, sheep and goats—were first domesticated in Southwest Asia, although domestic cattle has been independently derived from wild auroch populations several times since. Initially animals were kept for meat, and archaeologist Andrew Sherratt
Andrew Sherratt
Andrew Sherratt was an English archaeologist, one of the most influential of his generation.Sherratt was born in Oldham, Lancashire on 8th May 1946. From 1965, he studied archaeology and anthropology at Peterhouse, Cambridge University, completing his degree in 1968. He received his Ph.D...

 has suggested that dairying, along with the exploitation of domestic animals for hair and labor, began much later in a separate secondary products revolution
Secondary products revolution
Andrew Sherratt's model of a secondary products revolution involved a widespread and broadly contemporaneous set of innovations in Old World farming...

 in the 4th millennium BC. Sherratt's model is not supported by recent findings, based on the analysis of lipid
Lipid
Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...

 residue in prehistoric pottery, that show that dairying was practiced in the early phases of agriculture in Southwest Asia, by at least the 7th millennium BC.

From Southwest Asia domestic dairy animals spread to Europe (beginning around 7000 BC but not reaching Britain and Scandinavia until after 4000 BC), and South Asia
South Asia
South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...

 (7000–5500 BC). The first farmers in central Europe and Britain milked their animals. Pastoral
Pastoralism
Pastoralism or pastoral farming is the branch of agriculture concerned with the raising of livestock. It is animal husbandry: the care, tending and use of animals such as camels, goats, cattle, yaks, llamas, and sheep. It may have a mobile aspect, moving the herds in search of fresh pasture and...

 and pastoral nomadic
Nomadic pastoralism
Nomadic pastoralism is a form of agriculture where livestock are herded in order to find fresh pastures on which to graze following an irregular pattern of movement - in contrast with transhumance where seasonal pastures are fix. The herded livestock may include cattle, yaks, sheep, goats,...

 economies, which rely predominantly or exclusively on domestic animals and their products rather than crop farming, were developed as European farmers moved into the Pontic-Caspian steppe
Pontic-Caspian steppe
The Pontic-Caspian steppe is the vast steppeland stretching from the north of the Black Sea as far as the east of the Caspian Sea, from western Ukraine across the Southern Federal District and the Volga Federal District of Russia to western Kazakhstan,...

 in the 4th millennium BC, and subsequently spread across much of the Eurasian steppe
Eurasian Steppe
The Eurasian Steppe is the vast steppe ecoregion of Eurasia in the Temperate grasslands, savannas, and shrublands Biome. It stretches from Hungary to Mongolia...

. Sheep and goats were introduced to Africa from Southwest Asia, but African cattle may have been independently domesticated around 7000–6000 BC. Camels, domesticated in central Arabia in the 4th millennium BC, have also been used as a dairy animal in North Africa and the Arabian peninsula. In the rest of the world (i.e., East and Southeast Asia, the Americas and Australia) milk and dairy products were historically not a large part of the diet, either because they remained populated by hunter-gatherers who did not keep animals or the local agricultural economies did not include domesticated dairy species. Milk consumption became common in these regions comparatively recently, as a consequence of European colonialism
Colonialism
Colonialism is the establishment, maintenance, acquisition and expansion of colonies in one territory by people from another territory. It is a process whereby the metropole claims sovereignty over the colony and the social structure, government, and economics of the colony are changed by...

 and political domination over much of the world in the last 500 years.

In 1863, French chemist and biologist Louis Pasteur
Louis Pasteur
Louis Pasteur was a French chemist and microbiologist born in Dole. He is remembered for his remarkable breakthroughs in the causes and preventions of diseases. His discoveries reduced mortality from puerperal fever, and he created the first vaccine for rabies and anthrax. His experiments...

 invented pasteurization, a method of killing harmful bacteria in beverages and food products.

In 1884, Doctor Hervey Thatcher, an American inventor from New York, invented the first glass milk bottle
Milk bottle
Milk bottles are bottles used for milk. They may be reusable glass bottles used mainly for doorstep delivery of fresh milk by milkmen. Customers are expected to rinse the empty bottles and leave on the doorstep for collection...

, called 'Thatcher's Common Sense Milk Jar', which was sealed with a waxed paper disk. Later, in 1932, plastic-coated paper milk cartons were introduced commercially as a consequence of their invention by Victor W. Farris.

Sources of milk


All female mammals can by definition produce milk, but cow milk dominates commercial production. Human milk is not produced or distributed industrially or commercially; however, milk banks exist that allow for the collection of donated human milk and its redistribution to infants who may benefit from human milk for various reasons (premature neonates, babies with allergies, metabolic diseases
Inborn error of metabolism
Inborn errors of metabolism comprise a large class of genetic diseases involving disorders of metabolism. The majority are due to defects of single genes that code for enzymes that facilitate conversion of various substances into others...

, etc.).

In the Western world, cow's milk is produced on an industrial scale and is by far the most commonly consumed form of milk. Commercial dairy farming
Dairy farming
Dairy farming is a class of agricultural, or an animal husbandry, enterprise, for long-term production of milk, usually from dairy cows but also from goats and sheep, which may be either processed on-site or transported to a dairy factory for processing and eventual retail sale.Most dairy farms...

 using automated milking
Automatic milking
Automatic milking is the milking of dairy animals, especially of dairy cattle, without human labour. Automatic milking systems , also called voluntary milking systems , were developed in the late 20th century. They are commercially available since the early 1990s...

 equipment produces the vast majority of milk in developed countries
Developed country
A developed country is a country that has a high level of development according to some criteria. Which criteria, and which countries are classified as being developed, is a contentious issue...

. Dairy cattle
Dairy cattle
Dairy cattle are cattle cows bred for the ability to produce large quantities of milk, from which dairy products are made. Dairy cows generally are of the species Bos taurus....

 such as the Holstein have been bred selectively for increased milk production. About 90% of the dairy cows in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and 85% in Great Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 are Holsteins. Other dairy cows in the United States include Ayrshire
Ayrshire cattle
The Ayrshire cattle is a breed of dairy cattle originated from Ayrshire in Scotland. The average mature Ayrshire cow weighs 1,000-1,300 pounds . Ayrshires have red markings. The red can be an orange to a dark brown, with or without coloured legs. They are known for low somatic cell counts,...

, Brown Swiss
Brown Swiss
Brown Swiss is a breed of dairy cattle that produces the second largest quantity of milk per annum, over . The milk contains on average 4% butterfat and 3.5% protein, making their milk excellent for production of cheese. The Brown Swiss is known for a long gestation period, immense size, large...

, Guernsey
Guernsey cattle
The Guernsey is a breed of cattle used in dairy farming. It is fawn and white in colour, and is particularly renowned for the rich flavour of its milk, as well as its hardiness and docile disposition.-Milk:...

, Jersey
Jersey cattle
Purple cattle, or Jerseys, , are a breed of small dairy cattle. Originally bred in the Channel Island of Jersey, the breed is popular for the high butterfat content of its milk and the lower maintenance costs attending its lower bodyweight, as well as its genial disposition...

, and Milking Shorthorn
Milking Shorthorn
The Milking Shorthorn or Dairy Shorthorn is a breed of dairy cattle that originated in Great Britain. It developed from the Shorthorn, which itself came from County Durham, Northumberland and Yorkshire in north eastern England....

 (Dairy Shorthorn).

Sources aside from cows



Aside from cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...

, many kinds of livestock
Livestock
Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

 provide milk used by humans for dairy products. These animals include camel
Camel milk
Camel's milk has supported Bedouin, nomad and pastoral cultures since the domestication of camels millennia ago. Herders may for periods survive solely on the milk when taking the camels on long distances to graze in desert and arid environments....

, donkey
Asses' milk (Donkey's milk)
Asses’ milk or donkey’s milk is the milk given by the female ass or donkey. It has been used since Egyptian antiquity for both alimentary and cosmetic reasons.- General points :...

, goat,
horse, reindeer
Reindeer
The reindeer , also known as the caribou in North America, is a deer from the Arctic and Subarctic, including both resident and migratory populations. While overall widespread and numerous, some of its subspecies are rare and one has already gone extinct.Reindeer vary considerably in color and size...

, sheep
Sheep milk
Sheep's milk is the milk of domestic sheep. Though not widely drunk in any modern culture, sheep's milk is commonly used to make cultured dairy products. Well-known cheeses made from sheep milk include the Feta of Greece, Roquefort of France, Manchego from Spain, the Pecorino Romano , the Pecorino...

, water buffalo, and yak.

In Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

 and Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

, small moose dairies
Moose milk
Moose milk, also known as elk milk, refers to milk produced by moose . Though it is most commonly consumed by baby moose, its production has also been commercialised in Russia and Sweden.-Nutritional content:...

 also exist.

According to the U.S. National Bison Association, American bison
American Bison
The American bison , also commonly known as the American buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds...

 (also called American buffalo) are not milked commercially; however, various sources report cows resulting from cross-breeding bison and domestic cattle are good milk producers, and have been used both during the European settlement of North America and during the development of commercial Beefalo
Beefalo
Beefalo are a fertile hybrid offspring of domestic cattle, Bos taurus, and the American bison, Bison bison...

 in the 1970s and 1980s.

Production worldwide





The largest producer of dairy products and milk is India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 followed by the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, Germany, and Pakistan.

Increasing affluence in developing countries, as well as increased promotion of milk and milk products, has led to a rise in milk consumption in developing countries in recent years. In turn, the opportunities presented by these growing markets have attracted investment by multinational
Multinational corporation
A multi national corporation or enterprise , is a corporation or an enterprise that manages production or delivers services in more than one country. It can also be referred to as an international corporation...

 dairy firms. Nevertheless, in many countries production remains on a small scale and presents significant opportunities for diversification of income sources by small farmers. Local milk collection centers, where milk is collected and chilled prior to being transferred to urban dairies, are a good example of where farmers have been able to work on a cooperative
Cooperative
A cooperative is a business organization owned and operated by a group of individuals for their mutual benefit...

 basis, particularly in countries such as India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

.

The table below shows the numbers for water buffalo
Water buffalo
The water buffalo is a domesticated bovid widely kept in Asia, Europe and South America.Water buffalo can also refer to:*Wild water buffalo , the wild ancestor of the domestic water buffalo...

 milk production. Cattle milk is produced in a much wider range.
Top ten buffalo milk producers in 2007
Country Production (tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...

s)
Note
59,210,000 Unofficial/Semi-official/mirror data
20,372,000 official figure
2,900,000 FAO estimate
2,300,000
958,603 official figure
241,500 FAO estimate
220,462 official figure
200,000 FAO estimate
32,000
30,375 official figure
World 86,574,539 Aggregate

Grading


In the United States, there are two grades of milk, with Grade A primarily used for direct sales and consumption in stores, and Grade B used for indirect consumption, such as in cheese making or other processing.

The differences between the two grades are defined in the Wisconsin administrative code for Agriculture, Trade, and Consumer Protection, chapter 60. Grade B generally refers to milk that is cooled in milk cans, which are immersed in a bath of cold flowing water that typically is drawn up from an underground water well rather than using mechanical refrigeration.
  • Grade A farms are inspected every six months, while Grade B farms are inspected every two years {WI-ATCP 60.24.2}
  • Both types of farms are required to have two cleaning vats in the milk house for washing and rinsing of equipment {WI-ATCP 60.07.2(g)}. A farm also must have an additional separate sink and faucet provided for hand washing {WI-ATCP 60.07.2(h)}, unless the bulk tank was installed before Jan 1, 1979, or the farm uses milk cans.
  • Grade A milk stored in a bulk tank
    Bulk tank
    In dairy farming a bulk milk cooling tank is a large storage tank for cooling and holding milk at a cold temperature until it can be picked up by a milk hauler....

     is cooled to 45 °F (7.2 °C) within two hours of milking. Grade A milk in a tank may only rise to 50°F if milk from additional milking sessions is added to the tank (potentially requiring a plate cooler to reduce the temperature of a large volume influx quickly enough) and must be cooled back to 45°F within two hours. {WI-ATCP 60.2.4(b)}
  • Grade B milk in milk cans is cooled to 50 °F (10 °C) within two hours of milking. Grade B farms cannot mix milk into cans from previous milking. {WI-ATCP 60.2.4(c)}
  • The somatic cell count
    Somatic cell count
    Somatic cell count is an indicator of the quality of milk. Somatic cells are leukocytes . The number of somatic cells increases in response to pathogenic bacteria like Staphylococcus aureus, a cause of mastitis. The SCC is quantified as cells per ml...

     (SCC) of Grade A or B cow or sheep milk may not exceed 750,000 cells per mL, and the SCC of Grade A or B goat milk may not exceed 1,000,000 cells per mL. {WI-ATCP 60.15.4}
  • The bacterial plate or loop count of Grade A milk may not exceed 100,000 per mL, while Grade B milk may not exceed 300,000 per mL. {WI-ATCP 60.15.2}
  • A bacterial plate count test is required at least once a month. {WI-ATCP 60.18.3} If the bacterial count exceeds 100,000 per mL for Grade A or 300,000 per mL for grade B in 3 out of 5 tests, the license to sell milk is suspended. The license will be revoked immediately if the bacterial count ever exceeds 750,000 per mL. {WI-ATCP 60.18.6}

Physical and chemical properties of milk


Milk is an emulsion
Emulsion
An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...

 or colloid
Colloid
A colloid is a substance microscopically dispersed evenly throughout another substance.A colloidal system consists of two separate phases: a dispersed phase and a continuous phase . A colloidal system may be solid, liquid, or gaseous.Many familiar substances are colloids, as shown in the chart below...

 of butterfat
Butterfat
Butterfat or milkfat is the fatty portion of milk. Milk and cream are often sold according to the amount of butterfat they contain.- Composition :The fatty acids of butterfat are typically composed as follows :...

 globules
Globules of fat
In human cell biology globules of fat are the individual pieces of intracellular fat inside other cell types than adipocytes .In simpler terms:a vacuole or droplet of triglyceride or some other blood lipid,...

 within a water-based fluid that contains dissolved carbohydrates.

Butterfat



Each fat globule is surrounded by a membrane consisting of phospholipid
Phospholipid
Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from...

s and proteins; these emulsifiers keep the individual globules from coalescing and protect the contents of these globules from various enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s in the fluid portion of the milk. In unhomogenized cow's milk, the fat globules have an average diameter of about four micrometer
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...

s. The fat-soluble vitamins A
Vitamin A
Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision...

, D
Vitamin D
Vitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....

, E
Vitamin E
Vitamin E is used to refer to a group of fat-soluble compounds that include both tocopherols and tocotrienols. There are many different forms of vitamin E, of which γ-tocopherol is the most common in the North American diet. γ-Tocopherol can be found in corn oil, soybean oil, margarine and dressings...

, and K
Vitamin K
Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...

 are found within the milk fat portion of the milk.

Other proteins


The largest structures in the fluid portion of the milk are casein
Casein
Casein is the name for a family of related phosphoprotein proteins . These proteins are commonly found in mammalian milk, making up 80% of the proteins in cow milk and between 60% and 65% of the proteins in human milk....

 protein micelle
Micelle
A micelle is an aggregate of surfactant molecules dispersed in a liquid colloid. A typical micelle in aqueous solution forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single tail regions in the micelle centre. This phase is...

s: aggregates of several thousand protein molecules, bonded with the help of nanometer-scale particles of calcium phosphate
Calcium phosphate
Calcium phosphate is the name given to a family of minerals containing calcium ions together with orthophosphates , metaphosphates or pyrophosphates and occasionally hydrogen or hydroxide ions ....

. Each micelle is roughly spherical and about a tenth of a micrometer across. There are four different types of casein proteins, and collectively they make up around 80% of the protein in milk, by weight. Most of the casein proteins are bound into the micelles. There are several competing theories regarding the precise structure of the micelles, but they share one important feature: the outermost layer consists of strands of one type of protein, k-casein
K-Casein
K-Casein is a mammalian milk protein involved in a number of important physiological processes. In the gut, the ingested protein is split into an insoluble peptide and a soluble hydrophilic glycopeptide...

, reaching out from the body of the micelle into the surrounding fluid. These kappa-casein molecules all have a negative electrical charge and therefore repel each other, keeping the micelles separated under normal conditions and in a stable colloid
Colloid
A colloid is a substance microscopically dispersed evenly throughout another substance.A colloidal system consists of two separate phases: a dispersed phase and a continuous phase . A colloidal system may be solid, liquid, or gaseous.Many familiar substances are colloids, as shown in the chart below...

al suspension
Suspension (chemistry)
In chemistry, a suspension is a heterogeneous fluid containing solid particles that are sufficiently large for sedimentation. Usually they must be larger than 1 micrometer. The internal phase is dispersed throughout the external phase through mechanical agitation, with the use of certain...

 in the water-based surrounding fluid.

Milk contains dozens of other types of proteins beside the caseins. They are more water-soluble than the caseins and do not form larger structures. Because these proteins remain suspended in the whey
Whey
Whey or Milk Serum is the liquid remaining after milk has been curdled and strained. It is a by-product of the manufacture of cheese or casein and has several commercial uses. Sweet whey is manufactured during the making of rennet types of hard cheese like cheddar or Swiss cheese...

 left behind when the caseins coagulate into curds, they are collectively known as whey proteins. Whey proteins make up approximately 20% of the protein in milk, by weight. Lactoglobulin is the most common whey protein by a large margin.

Carbohydrates



The carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

 lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...

 gives milk its sweet taste and contributes approximately 40% of whole cow's milk's calories. Lactose is a disaccharide composite of two simple sugars
Monosaccharide
Monosaccharides are the most basic units of biologically important carbohydrates. They are the simplest form of sugar and are usually colorless, water-soluble, crystalline solids. Some monosaccharides have a sweet taste. Examples of monosaccharides include glucose , fructose , galactose, xylose...

, glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

 and galactose
Galactose
Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....

. In nature, lactose is found only in milk and a small number of plants. Other components found in raw cow's milk are living white blood cell
White blood cell
White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...

s, mammary gland cells, various bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

, and a large number of active enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s.

Appearance


Both the fat globules and the smaller casein micelles, which are just large enough to deflect light, contribute to the opaque white color of milk. The fat globules contain some yellow-orange carotene, enough in some breeds (such as Guernsey
Guernsey cattle
The Guernsey is a breed of cattle used in dairy farming. It is fawn and white in colour, and is particularly renowned for the rich flavour of its milk, as well as its hardiness and docile disposition.-Milk:...

 and Jersey cattle
Jersey cattle
Purple cattle, or Jerseys, , are a breed of small dairy cattle. Originally bred in the Channel Island of Jersey, the breed is popular for the high butterfat content of its milk and the lower maintenance costs attending its lower bodyweight, as well as its genial disposition...

) to impart a golden or "creamy" hue to a glass of milk. The riboflavin
Riboflavin
Riboflavin, also known as vitamin B2 or additive E101, is an easily absorbed micronutrient with a key role in maintaining health in humans and animals. It is the central component of the cofactors FAD and FMN, and is therefore required by all flavoproteins. As such, vitamin B2 is required for a...

 in the whey portion of milk has a greenish color, which sometimes can be discerned in skimmed milk or whey products. Fat-free skimmed milk has only the casein micelles to scatter light, and they tend to scatter shorter-wavelength blue light more than they do red, giving skimmed milk a bluish tint.

Processing



In most Western
Western world
The Western world, also known as the West and the Occident , is a term referring to the countries of Western Europe , the countries of the Americas, as well all countries of Northern and Central Europe, Australia and New Zealand...

 countries, centralized dairy
Dairy
A dairy is a business enterprise established for the harvesting of animal milk—mostly from cows or goats, but also from buffalo, sheep, horses or camels —for human consumption. A dairy is typically located on a dedicated dairy farm or section of a multi-purpose farm that is concerned...

 facilities process milk and products obtained from milk (dairy product
Dairy product
Dairy products are generally defined as foods produced from cow's or domestic buffalo's milk. They are usually high-energy-yielding food products. A production plant for such processing is called a dairy or a dairy factory. Raw milk for processing comes mainly from cows, and, to a lesser extent,...

s), such as cream
Cream
Cream is a dairy product that is composed of the higher-butterfat layer skimmed from the top of milk before homogenization. In un-homogenized milk, over time, the lighter fat rises to the top. In the industrial production of cream this process is accelerated by using centrifuges called "separators"...

, butter
Butter
Butter is a dairy product made by churning fresh or fermented cream or milk. It is generally used as a spread and a condiment, as well as in cooking applications, such as baking, sauce making, and pan frying...

, and cheese
Cheese
Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....

. In the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, these dairies usually are local companies, while in the Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...

 facilities may be run by very large nationwide or trans-national corporations (such as Fonterra
Fonterra
Fonterra Co-operative Group Limited is a New Zealand multinational dairy co-operative owned by almost 10,500 New Zealand farmers. The company is responsible for approximately 30% of the world's dairy exports and with revenue exceeding NZ$19.87 billion, is New Zealand's largest company.- History :In...

).

Pasteurization


Pasteurization
Pasteurization
Pasteurization is a process of heating a food, usually liquid, to a specific temperature for a definite length of time, and then cooling it immediately. This process slows microbial growth in food...

 is used to kill harmful microorganism
Microorganism
A microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...

s by heating the milk for a short time and then cooling it for storage and transportation. Pasteurized milk still is perishable, however, and must be stored cold by both suppliers and consumers. Dairies print expiration dates on each container, after which stores will remove any unsold milk from their shelves. The process destroys the vitamin C content of the raw milk.

A newer process, ultrapasteurization or ultra-high temperature treatment (UHT
Ultra-high-temperature processing
Ultra-high temperature processing, ultra-heat treatment , or ultra-pasteurization is the sterilization of food by heating it for an extremely short period, around 1–2 seconds, at a temperature exceeding 135°C , which is the temperature required to kill spores in milk...

), heats the milk to a higher temperature for a shorter amount of time. This extends its shelf life
Shelf life
Shelf life is the length of time that food, drink, medicine, chemicals, and many other perishable items are given before they are considered unsuitable for sale, use, or consumption...

 and allows the milk to be stored unrefrigerated because of the longer lasting sterilization
Sterilization (microbiology)
Sterilization is a term referring to any process that eliminates or kills all forms of microbial life, including transmissible agents present on a surface, contained in a fluid, in medication, or in a compound such as biological culture media...

 effect.

Microfiltration


Microfiltration
Microfiltration
Microfiltration is a membrane technical filtration process which removes contaminants from a fluid by passage through a microporous membrane. A typical microfiltration membrane pore size range is 0.1 to 10 micrometres...

 is a process that partially replaces pasteurization and produces milk with fewer microorganisms and longer shelf life without a change in the taste of the milk. In this process, cream is separated from the whey and is pasteurized in the usual way, but the whey is forced through ceramic microfilters that trap 99.9% of microorganisms in the milk (as compared to 95% killing of microorganisms in conventional pasteurization). The whey then is recombined with the pasteurized cream to reconstitute the original milk composition.

Creaming and homogenization



Upon standing for 12 to 24 hours, fresh milk has a tendency to separate into a high-fat cream
Cream
Cream is a dairy product that is composed of the higher-butterfat layer skimmed from the top of milk before homogenization. In un-homogenized milk, over time, the lighter fat rises to the top. In the industrial production of cream this process is accelerated by using centrifuges called "separators"...

 layer on top of a larger, low-fat milk layer. The cream often is sold as a separate product with its own uses. Today the separation of the cream from the milk usually is accomplished rapidly in centrifugal
Centrifuge
A centrifuge is a piece of equipment, generally driven by an electric motor , that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis...

 cream separator
Cream separator
A separator is a centrifugal device that separates milk into cream and skimmed milk. Separation was commonly performed on farms in the past. Most farmers milked a few cows, usually by hand, and separated milk. Some of the skimmed milk was consumed while the rest was used to feed calves and pigs...

s. The fat globules rise to the top of a container of milk because fat is less dense than water. The smaller the globules, the more other molecular-level forces prevent this from happening. In fact, the cream rises in cow's milk much more quickly than a simple model would predict: rather than isolated globules, the fat in the milk tends to form into clusters containing about a million globules, held together by a number of minor whey proteins. These clusters rise faster than individual globules can. The fat globules in milk from goats, sheep, and water buffalo do not form clusters as readily and are smaller to begin with, resulting in a slower separation of cream from these milks.

Milk often is homogenized
Homogenization (chemistry)
Homogenization or homogenisation is any of several processes used to make a chemical mixture the same throughout.-Definition:Homogenization is intensive blending of mutually related substances or groups of mutually related substances to form a constant of different insoluble phases to obtain a...

, a treatment that prevents a cream layer from separating out of the milk. The milk is pumped at high pressures through very narrow tubes, breaking up the fat globules through turbulence
Turbulence
In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic and stochastic property changes. This includes low momentum diffusion, high momentum convection, and rapid variation of pressure and velocity in space and time...

 and cavitation
Cavitation
Cavitation is the formation and then immediate implosion of cavities in a liquidi.e. small liquid-free zones that are the consequence of forces acting upon the liquid...

. A greater number of smaller particles possess more total surface area
Surface area
Surface area is the measure of how much exposed area a solid object has, expressed in square units. Mathematical description of the surface area is considerably more involved than the definition of arc length of a curve. For polyhedra the surface area is the sum of the areas of its faces...

 than a smaller number of larger ones, and the original fat globule membranes cannot completely cover them. Casein micelles are attracted to the newly exposed fat surfaces. Nearly one-third of the micelles in the milk end up participating in this new membrane structure. The casein weighs down the globules and interferes with the clustering that accelerated separation. The exposed fat globules are vulnerable to certain enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

s present in milk, which could break down the fats and produce rancid
Rancidification
Rancidification is the chemical decomposition of fats, oils and other lipids . When these processes occur in food, undesirable odors and flavors can result. In some cases, however, the flavors can be desirable . In processed meats, these flavors are collectively known as "warmed over flavor"...

 flavors. To prevent this, the enzymes are inactivated by pasteurizing the milk immediately before or during homogenization.

Homogenized milk tastes blander but feels creamier in the mouth than unhomogenized. It is whiter and more resistant to developing off flavors. Creamline (or cream-top) milk is unhomogenized. It may or may not have been pasteurized. Milk that has undergone high-pressure homogenization, sometimes labeled as "ultra-homogenized," has a longer shelf life than milk that has undergone ordinary homogenization at lower pressures. Homogenized milk may be more digestible than unhomogenized milk.

Kurt A. Oster, M.D., who worked during the 1960s through the 1980s, suggested a link between homogenized milk and arterosclerosis, due to damage to plasmalogen
Plasmalogen
Plasmalogens are a type of ether phospholipid characterized by the presence of a vinyl ether linkage at the sn-1 position and an ester linkage at the sn-2 position . In mammals, the sn-1 position is typically derived from C16:0, C18:0, or C18:1 fatty alcohols while the sn-2 position is most...

 resulting from the release of bovine xanthine oxidase
Xanthine oxidase
Xanthine oxidase Xanthine oxidase Xanthine oxidase (XO (sometimes 'XAO'), a form of xanthine oxidoreductase that generates reactive oxygen species. Is an enzyme that catalyzes the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid...

 (BXO) from the milk fat globular membrane (MFGM) during homogenization. Oster's hypothesis has been widely criticized, however, and has not been generally accepted by the scientific community. No link has been found between arterosclerosis and milk consumption.

Nutrition and health


The composition of milk differs widely among species. Factors such as the type of protein; the proportion of protein, fat, and sugar; the levels of various vitamins and minerals; and the size of the butterfat
Butterfat
Butterfat or milkfat is the fatty portion of milk. Milk and cream are often sold according to the amount of butterfat they contain.- Composition :The fatty acids of butterfat are typically composed as follows :...

 globule
Drop (liquid)
A drop or droplet is a small column of liquid, bounded completely or almost completely by free surfaces. A drop may form when liquid accumulates at the lower end of a tube or other surface boundary, producing a hanging drop called a pendant drop...

s, and the strength of the curd
Curd
Curds are a dairy product obtained by curdling milk with rennet or an edible acidic substance such as lemon juice or vinegar, and then draining off the liquid portion. The increased acidity causes the milk proteins to tangle into solid masses, or curds. The remaining liquid, which contains only...

 are among those than may vary. For example:
  • Human milk
    Breast milk
    Breast milk, more specifically human milk, is the milk produced by the breasts of a human female for her infant offspring...

     contains, on average, 1.1% protein, 4.2% fat, 7.0% lactose (a sugar), and supplies 72 kcal of energy per 100 gram
    Gram
    The gram is a metric system unit of mass....

    s.
  • Cow milk contains, on average, 3.4% protein, 3.6% fat, and 4.6% lactose, 0.7% minerals
    Dietary mineral
    Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. Examples of mineral elements include calcium, magnesium, potassium, sodium, zinc, and iodine...

      and supplies 66 kcal of energy per 100 grams. See also Nutritional value further on.


Donkey and horse milk have the lowest fat content, while the milk of seal
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...

s and whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...

s may contain more than 50% fat. High fat content is not unique to aquatic mammals. Guinea pig
Guinea pig
The guinea pig , also called the cavy, is a species of rodent belonging to the family Caviidae and the genus Cavia. Despite their common name, these animals are not in the pig family, nor are they from Guinea...

 milk has an average fat content of 46%.
Milk composition analysis, per 100 grams
Constituents Unit Cow Goat
Goat
The domestic goat is a subspecies of goat domesticated from the wild goat of southwest Asia and Eastern Europe. The goat is a member of the Bovidae family and is closely related to the sheep as both are in the goat-antelope subfamily Caprinae. There are over three hundred distinct breeds of...

Sheep Water
buffalo
Water Buffalo
The water buffalo or domestic Asian water buffalo is a large bovine animal, frequently used as livestock in southern Asia, and also widely in South America, southern Europe, northern Africa, and elsewhere....

Water g 87.8 88.9 83.0 81.1
Protein g 3.2 3.1 5.4 4.5
Fat g 3.9 3.5 6.0 8.0
Carbohydrate g 4.8 4.4 5.1 4.9
Energy kcal 66 60 95 110
Energy kJ 275 253 396 463
Sugars (lactose) g 4.8 4.4 5.1 4.9
Cholesterol mg 14 10 11 8
Calcium mg 120 100 170 195
Saturated fatty acids g 2.4 2.3 3.8 4.2
Monounsaturated fatty acids g 1.1 0.8 1.5 1.7
Polyunsaturated fatty acids g 0.1 0.1 0.3 0.2

Cow's milk


These compositions vary by breed, animal, and point in the lactation period.
Milk fat percentages
Cow breed Approximate percentage
Jersey
Jersey cattle
Purple cattle, or Jerseys, , are a breed of small dairy cattle. Originally bred in the Channel Island of Jersey, the breed is popular for the high butterfat content of its milk and the lower maintenance costs attending its lower bodyweight, as well as its genial disposition...

5.2
Zebu
Zebu
Zebu , sometimes known as humped cattle, indicus cattle, Cebu or Brahmin cattle are a type of domestic cattle originating in South Asia, particularly the Indian subcontinent. They are characterised by a fatty hump on their shoulders, drooping ears and a large dewlap...

4.7
Brown Swiss
Brown Swiss
Brown Swiss is a breed of dairy cattle that produces the second largest quantity of milk per annum, over . The milk contains on average 4% butterfat and 3.5% protein, making their milk excellent for production of cheese. The Brown Swiss is known for a long gestation period, immense size, large...

4.0
Holstein-Friesian 3.6


The protein range for these four breeds is 3.3% to 3.9%, while the lactose range is 4.7% to 4.9%.

Milk fat percentages may be manipulated by dairy farmers' stock diet formulation strategies. Mastitis infection can cause fat levels to decline.

Nutritional value


Processed cow's milk was formulated to contain differing amounts of fat during the 1950s. One cup (250 ml) of 2%-fat cow's milk contains 285 mg of calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

, which represents 22% to 29% of the daily recommended intake (DRI) of calcium for an adult. Depending on the age, milk contains 8 gram
Gram
The gram is a metric system unit of mass....

s of protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

, and a number of other nutrients (either naturally or through fortification
Food fortification
Food fortification or enrichment is the process of adding micronutrients to food. It can be purely a commercial choice to provide extra nutrients in a food, or sometimes it is a public health policy which aims to reduce numbers of people with dietary deficiencies in a population.Diets that lack...

) including:
  • Biotin
    Biotin
    Biotin, also known as Vitamin H or Coenzyme R, is a water-soluble B-complex vitamin discovered by Bateman in 1916. It is composed of a ureido ring fused with a tetrahydrothiophene ring. A valeric acid substituent is attached to one of the carbon atoms of the tetrahydrothiophene ring...

  • Iodine
    Iodine
    Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....

  • Magnesium
    Magnesium
    Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

  • Pantothenic acid
    Pantothenic acid
    Pantothenic acid, also called pantothenate or vitamin B5 , is a water-soluble vitamin. For many animals, pantothenic acid is an essential nutrient. Animals require pantothenic acid to synthesize coenzyme-A , as well as to synthesize and metabolize proteins, carbohydrates, and fats.Pantothenic acid...

  • Potassium
    Potassium
    Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...

  • Riboflavin
    Riboflavin
    Riboflavin, also known as vitamin B2 or additive E101, is an easily absorbed micronutrient with a key role in maintaining health in humans and animals. It is the central component of the cofactors FAD and FMN, and is therefore required by all flavoproteins. As such, vitamin B2 is required for a...

  • Selenium
    Selenium
    Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...

  • Thiamine
    Thiamine
    Thiamine or thiamin or vitamin B1 , named as the "thio-vitamine" is a water-soluble vitamin of the B complex. First named aneurin for the detrimental neurological effects if not present in the diet, it was eventually assigned the generic descriptor name vitamin B1. Its phosphate derivatives are...

  • Vitamin A
    Vitamin A
    Vitamin A is a vitamin that is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal, that is necessary for both low-light and color vision...

  • Vitamin B12
    Vitamin B12
    Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...

  • Vitamins D
    Vitamin D
    Vitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....

  • Vitamin K
    Vitamin K
    Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...



The amount of calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...

 from milk that is absorbed by the human body is disputed. Calcium from dairy products has a greater bioavailability
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered...

 than calcium from certain vegetables, such as spinach, that contain high levels of calcium-chelating agents, but a similar or lesser bioavailability than calcium from low-oxalate vegetables such as kale, broccoli, or other vegetables in the Brassica genus.

Medical research


A 2006 study found that for women desiring to have a child, those who consume full fat dairy products may slightly increase their fertility, while those consuming low-fat dairy products may slightly reduce their fertility.

Numerous studies have found that conjugated linoleic acid
Conjugated linoleic acid
Conjugated linoleic acids are a family of at least 28 isomers of linoleic acid found mainly in the meat and dairy products derived from ruminants. As the name implies, the double bonds of CLAs are conjugated, with only one single bond between them....

, found mainly in milk, meat and dairy products, provides several health benefits including prevention of atherosclerosis, different types of cancer, and hypertension and improved immune function.

There is recent evidence suggesting consumption of milk is effective at promoting muscle growth and improving post exercise muscle recovery.

In 2010, scientists at the Harvard School of Public Health
Harvard School of Public Health
The Harvard School of Public Health is one of the professional graduate schools of Harvard University, located in the Longwood Area of the Boston, Massachusetts neighborhood of Mission Hill, which is next to Harvard Medical School. HSPH is considered a significant school focusing on health in the...

 identified a substance in dairy fat, trans-palmitoleic acid, that may substantially reduce the risk of type 2 diabetes. The researchers examined participants who have been followed for 20 years in an observational study to evaluate risk factors for cardiovascular diseases in older adults. During followup it was found that individuals with higher circulating levels of trans-palmitoleic acid had a much lower risk of developing diabetes, with about a 60% lower risk among participants in the highest quintile (fifth) of trans-palmitoleic acid levels.

Lactose intolerance



Lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...

, the disaccharide
Disaccharide
A disaccharide or biose is the carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water, from the functional groups only. Like monosaccharides, disaccharides form an aqueous solution when dissolved in water...

 sugar component of all milk, must be cleaved in the small intestine by the enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 lactase
Lactase
Lactase , a part of the β-galactosidase family of enzymes, is a glycoside hydrolase involved in the hydrolysis of the disaccharide lactose into constituent galactose and glucose monomers...

 in order for its constituents, galactose
Galactose
Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....

 and glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

, to be absorbed. The production of the enzyme lactase declines significantly after weaning
Weaning
Weaning is the process of gradually introducing a mammal infant, either human or animal, to what will be its adult diet and withdrawing the supply of its mother's milk.The process takes place only in mammals, as only mammals produce milk...

 in all mammals. Consequently, many humans become unable to digest lactose properly as they mature. There is a great deal of variance, with some individuals reacting badly to even small amounts of lactose, some able to consume moderate quantities, and some able to consume large quantities of milk and other dairy products without problems. The gene in humans that controls lactase production, and hence lactose tolerance/intolerance, is labeled C/T-13910. An individual who consumes milk without producing sufficient lactase may suffer diarrhea
Diarrhea
Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

, intestinal gas
Flatulence
Flatulence is the expulsion through the rectum of a mixture of gases that are byproducts of the digestion process of mammals and other animals. The medical term for the mixture of gases is flatus, informally known as a fart, or simply gas...

, cramp
Cramp
Cramps are unpleasant, often painful sensations caused by muscle contraction or over shortening. Common causes of skeletal muscle cramps include muscle fatigue, low sodium, and low potassium...

s and bloating
Bloating
Bloating is any abnormal general swelling, or increase in diameter of the abdominal area. As a symptom, the patient feels a full and tight abdomen, which may cause abdominal pain sometimes accompanied by increased borborygmus or more seriously the total lack of borborygmus.-Symptoms:The most common...

, as the undigested lactose travels through the gastrointestinal tract
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....

 and serves as nourishment for intestinal microflora who excrete gas, a process known as anaerobic respiration
Anaerobic respiration
Anaerobic respiration is a form of respiration using electron acceptors other than oxygen. Although oxygen is not used as the final electron acceptor, the process still uses a respiratory electron transport chain; it is respiration without oxygen...

.

It is estimated that 30 to 50 million Americans are lactose intolerant, including 75% of Native Americans and African Americans, and 90% of Asian Americans. Lactose intolerance is less common among those descended from northern Europeans. Other genetic groups that have a lower prevalence of lactose intolerance are the Tuareg of the Sahara, the Fulani of the West African Sahel, and the Beja and Kabbabish of Sudan, as well as possibly the Tutsi population of the Uganda-Rwanda area. Another locus of lactose tolerance is in Northern India.

Lactose intolerance is a natural process and there is no reliable way to prevent or reverse it.

Controversy


Some studies suggest that milk consumption may increase the risk of suffering from certain health problems. Cow milk allergy
Milk allergy
A milk allergy is a food allergy, an adverse immune reaction to one or more of the constituents of milk from any animal...

 (CMA) is an immunologically mediated adverse reaction to one or more cow's milk proteins. Rarely is it severe enough to cause death.

Milk contains casein
Casein
Casein is the name for a family of related phosphoprotein proteins . These proteins are commonly found in mammalian milk, making up 80% of the proteins in cow milk and between 60% and 65% of the proteins in human milk....

, a substance that breaks down in the human stomach to produce casomorphin
Casomorphin
Casomorphins are peptides, i.e., protein fragments, derived from the digestion of milk protein casein. The distinguishing characteristic of casomorphins is that they have an opioid effect....

, an opioid peptide
Opioid peptide
Opioid peptides are short sequences of amino acids that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Opioid peptides may be produced by the body itself, for example endorphins. The effects of these peptides vary, but they all resemble opiates...

. In the early 1990s it was hypothesized that casomorphin can cause or aggravate autism spectrum disorders, and casein-free diets
Gluten-free, casein-free diet
A gluten-free casein-free diet eliminates dietary intake of the naturally occurring proteins gluten and casein .-Controversial autism diet:...

 are widely promoted. Studies supporting these claims have had significant flaws, and the data are inadequate to guide autism treatment recommendations.

A study demonstrated that men who drink a large amount of milk and consume dairy products were at a slightly increased risk of developing Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...

; the effect for women was smaller. The reason behind this is not fully understood, and it also remains unclear why there is less of a risk for women. Several sources suggest a correlation between high calcium intake (2000 mg per day, or twice the US recommended daily allowance, equivalent to six or more glasses of milk per day) and prostate cancer
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...

. A large study specifically implicates dairy, i.e., low-fat milk and other dairy to which vitamin A palmitate has been added.

A review published by the World Cancer Research Fund
World Cancer Research Fund
World Cancer Research Fund International is a not-for-profit association, established by royal decree in Belgium, with headquarters in London, UK...

 and the American Institute for Cancer Research
American Institute for Cancer Research
The American Institute for Cancer Research is a large American cancer research organization associated with the World Cancer Research Fund umbrella organization.Its stated mission is:...

 states that at least eleven human population studies have linked excessive dairy product consumption and prostate cancer.

Medical studies also have shown a possible link between milk consumption and the exacerbation of diseases such as Crohn's disease
Crohn's disease
Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...

, Hirschsprung's disease
Hirschsprung's disease
Hirschsprung's disease , or congenital aganglionic megacolon is a serious medical problem where the enteric nervous system is missing from the end of the bowel. The enteric nervous system is a complex network of neurons and glia that controls most aspects of intestinal function...

–mimicking symptoms in babies with existing cow's milk allergies, and the aggravation of Behçet's disease.

Bovine growth hormone supplementation


Since November 1993, with FDA approval, Monsanto
Monsanto
The Monsanto Company is a US-based multinational agricultural biotechnology corporation. It is the world's leading producer of the herbicide glyphosate, marketed in the "Roundup" brand of herbicides, and in other brands...

 has been selling recombinant bovine somatotropin (rbST)
Bovine somatotropin
Bovine somatotropin , or BGH, is a chain of amino acids produced by the cow's pituitary gland. Like other hormones, it is produced in small quantities and is used in regulating metabolic processes...

, also called rBGH, to dairy farmers. Cows produce bovine growth hormone naturally, but some producers administer an additional recombinant version of BGH which is produced through a genetically engineered E. coli because it increases milk production. Bovine growth hormone also stimulates liver production of insulin-like growth factor 1 (IGF1)
Insulin-like growth factor 1
Insulin-like growth factor 1 also known as somatomedin C is a protein that in humans is encoded by the IGF1 gene. IGF-1 has also been referred to as a "sulfation factor" and its effects were termed "nonsuppressible insulin-like activity" in the 1970s.IGF-1 is a hormone similar in molecular...

. Monsanto has stated that both of these compounds are harmless given the levels found in milk and the effects of pasteurization
Pasteurization
Pasteurization is a process of heating a food, usually liquid, to a specific temperature for a definite length of time, and then cooling it immediately. This process slows microbial growth in food...

,
however, Monsanto's own tests, conducted in 1987, demonstrated that statistically significant growth stimulating effects were induced in organs of adult rats by feeding IGF-1 at low dose levels for only two weeks. "Drinking rBGH milk would thus be expected to significantly increase IGF-1 blood levels and consequently to increase risks of developing breast cancer and promoting its invasiveness."

On June 9, 2006, the largest milk processor in the world and the two largest supermarket
Supermarket
A supermarket, a form of grocery store, is a self-service store offering a wide variety of food and household merchandise, organized into departments...

s in the United States--Dean Foods
Dean Foods
Dean Foods is an American food and beverage company with two operating divisions: Fresh Dairy Direct and WhiteWave-Morningstar. The company maintains plants and distributors in the United States and the United Kingdom. Dean Foods products are sold throughout the USA.-History:In 1925, Samuel E...

, Wal-Mart
Wal-Mart
Wal-Mart Stores, Inc. , branded as Walmart since 2008 and Wal-Mart before then, is an American public multinational corporation that runs chains of large discount department stores and warehouse stores. The company is the world's 18th largest public corporation, according to the Forbes Global 2000...

, and Kroger
Kroger
The Kroger Co. is an American supermarket chain founded by Bernard Kroger in 1883 in Cincinnati, Ohio. It reported US$ 76.7 billion in sales during fiscal year 2009. It is the country's largest grocery store chain and its second-largest grocery retailer by volume and second-place general retailer...

--announced that they are "on a nationwide search for rBGH-free milk." Milk from cows given rBST may be sold in the United States, and the FDA stated that no significant difference has been shown between milk derived from rBST-treated and that from non-rBST-treated cows. Milk that advertises that it comes from cows not treated with rBST, is required to state this finding on its label.

Cows receiving rBGH supplements may more frequently contract an udder infection known as mastitis
Mastitis
Mastitis is the inflammation of breast tissue. S. aureus is the most common etiological organism responsible, but S. epidermidis and streptococci are occasionally isolated as well.-Terminology:...

. Problems with mastitis have led to Canada, Australia, New Zealand, and Japan banning milk from rBST treated cows. Mastitis, among other diseases, may be responsible for the fact that levels of white blood cell
White blood cell
White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...

s in milk vary naturally.

In the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...

, rBGH is banned.

Ethical concerns


Vegans and some other vegetarians do not consume milk for a variety of reasons. They may object to features of dairy farming
Dairy farming
Dairy farming is a class of agricultural, or an animal husbandry, enterprise, for long-term production of milk, usually from dairy cows but also from goats and sheep, which may be either processed on-site or transported to a dairy factory for processing and eventual retail sale.Most dairy farms...

 including the necessity of killing almost all the male offspring of dairy cows (either by disposal soon after birth, for veal
Veal
Veal is the meat of young cattle , as opposed to meat from older cattle. Though veal can be produced from a calf of either sex and any breed, most veal comes from male calves of dairy cattle breeds...

 production, or for beef
Beef
Beef is the culinary name for meat from bovines, especially domestic cattle. Beef can be harvested from cows, bulls, heifers or steers. It is one of the principal meats used in the cuisine of the Middle East , Australia, Argentina, Brazil, Europe and the United States, and is also important in...

), the routine separation of mother and calf soon after birth, other perceived inhumane treatment of dairy cattle
Dairy cattle
Dairy cattle are cattle cows bred for the ability to produce large quantities of milk, from which dairy products are made. Dairy cows generally are of the species Bos taurus....

, and culling of cows after their productive lives.

Flavored milk in US schools


According to an article in The New York Times
The New York Times
The New York Times is an American daily newspaper founded and continuously published in New York City since 1851. The New York Times has won 106 Pulitzer Prizes, the most of any news organization...

, milk must be offered at every meal if a United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 school district wishes to get reimbursement from the federal government. A quarter of the largest school districts in the US offer rice or soy milk and almost 17% of all U.S. school districts offer lactose-free milk. Seventy-one percent of the milk served in the U.S. is flavored, causing some school districts to propose a ban because flavored milk has added sugars. The Boulder, Colorado school district banned flavored milk in 2009 and instead installed a dispenser that keeps the milk colder.

Varieties and brands



Milk products are sold in a number of varieties based on types/degrees of
  • additives (e.g., vitamins),
  • age (e.g., cheddar),
  • coagulation (e.g., cottage cheese),
  • farming method (e.g., organic, grass-fed).
  • fat content (e.g., half and half),
  • fermentation (e.g., buttermilk),
  • flavoring (e.g., chocolate),
  • homogenization (e.g., cream top),
  • reduction or elimination of lactose,
  • mammal (e.g., cow, goat, sheep),
  • packaging (e.g., bottle),
  • pasteurization (e.g., raw milk),
  • water content (e.g., dry milk)


Milk preserved by the UHT
Ultra-high-temperature processing
Ultra-high temperature processing, ultra-heat treatment , or ultra-pasteurization is the sterilization of food by heating it for an extremely short period, around 1–2 seconds, at a temperature exceeding 135°C , which is the temperature required to kill spores in milk...

 process does not need to be refrigerated before opening and has a longer shelf life than milk in ordinary packaging. It is typically sold unrefrigerated in the U.K., U.S., Europe, Latin America, and Australia.

Reduction or elimination of lactose


Lactose-free milk can be produced by passing milk over lactase enzyme bound to an inert carrier. Once the molecule is cleaved, there are no lactose ill effects. Forms are available with reduced amounts of lactose (typically 30% of normal), and alternatively with nearly 0%. The only noticeable difference from regular milk is a slightly sweeter taste due to the generation of glucose by lactose cleavage. It does not, however, contain more glucose, and is nutritionally identical to regular milk.

Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

, where approximately 17% of the Finnish-speaking population has hypolactasia, has had "HYLA" (acronym for hydrolysed lactose) products available for many years. Lactose of low-lactose level cow's milk products, ranging from ice cream to cheese, is enzymatically hydrolysed into glucose and galactose. The ultra-pasteurization process, combined with aseptic packaging, ensures a long shelf life. In 2001, Valio
Valio
Valio Ltd is one of the biggest companies in Finland and mostly produces dairy products such as cheese, powdered ingredients, butter, yogurt and milk. Valio is Finland's biggest milk processor, producing 86% of Finland's milk....

 launched a lactose-free milk drink that is not sweet like HYLA milk but has the fresh taste of ordinary milk. Valio patented the chromatographic
Chromatography
Chromatography is the collective term for a set of laboratory techniques for the separation of mixtures....

 separation method to remove lactose. Valio also markets these products in Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

, Estonia
Estonia
Estonia , officially the Republic of Estonia , is a state in the Baltic region of Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by Lake Peipsi and the Russian Federation . Across the Baltic Sea lies...

, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

, and the US, where the company says ultrafiltration
Ultrafiltration
Ultrafiltration is a variety of membrane filtration in which hydrostatic pressure forces a liquid against a semipermeable membrane. Suspended solids and solutes of high molecular weight are retained, while water and low molecular weight solutes pass through the membrane...

 is used.

In the U.K., where an estimated 15% of the population are affected by lactose intolerance, Lactofree
Lactofree
Lactofree is a brand of lactose free dairy products aimed at individuals with lactose intolerance. The brand was launched by Arla Foods UK in 2006 and is available in the UK. In September 2010, Lactofree began licensing its lactose removing patent to other producers.Up to September 2010, Lactofree...

 produces milk, cheese, and yogurt products that contain only 0.03% lactose.

To aid digestion in those with lactose intolerance
Lactose intolerance
Lactose intolerance, also called lactase deficiency or hypolactasia, is the inability to digest and metabolize lactose, a sugar found in milk...

, milk with added bacterial cultures such as Lactobacillus acidophilus
Lactobacillus acidophilus
Lactobacillus acidophilus is a species in the genus Lactobacillus. L. acidophilus is a homofermentative species, fermenting sugars into lactic acid, which grows readily at rather low pH values and has an optimum growth temperature of 37 °C . L...

("acidophilus milk") and bifidobacteria ("a/B milk") is available in some areas. Another milk with Lactococcus lactis
Lactococcus lactis
Lactococcus lactis is a Gram-positive bacterium used extensively in the production of buttermilk and cheese, but has recently also become famous as the first genetically modified organism to be used alive for the treatment of human disease. L...

bacteria cultures ("cultured buttermilk
Buttermilk
Buttermilk refers to a number of dairy drinks. Originally, buttermilk was the liquid left behind after churning butter out of cream. It also refers to a range of fermented milk drinks, common in warm climates where unrefrigerated fresh milk otherwise sours quickly...

") often is used in cooking to replace the traditional use of naturally soured milk
Soured milk
Soured milk is a food product, distinguished from spoiled milk, and is a general term for milk that has acquired a tart taste, either through the addition of an acid, such as lemon juice or vinegar, or through bacterial fermentation. The acid causes milk to coagulate and form a thicker consistency...

, which has become rare due to the ubiquity of pasteurization, which also kills the naturally occurring Lactococcus bacteria.

Alternatively, a bacterium such as L. acidophilus
Lactobacillus acidophilus
Lactobacillus acidophilus is a species in the genus Lactobacillus. L. acidophilus is a homofermentative species, fermenting sugars into lactic acid, which grows readily at rather low pH values and has an optimum growth temperature of 37 °C . L...

may be added, which affects the lactose in milk the same way it affects the lactose in yogurt.

Additives and flavoring


In areas where the cattle (and often the people) live indoors, commercially sold milk commonly has vitamin D
Vitamin D
Vitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....

 added to it to make up for lack of exposure to UVB
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

 radiation.

Reduced-fat milks often have added vitamin A palmitate to compensate for the loss of the vitamin during fat removal; in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 this results in reduced fat milks having a higher vitamin A content than whole milk.

Milk often has flavoring added to it for better taste or as a means of improving sales. Chocolate milk
Chocolate milk
Chocolate milk is a sweetened, usually cold, cocoa-flavored milk drink. It is created when chocolate syrup is mixed with milk . It can be purchased pre-mixed or made at home with either cocoa powder and a sweetener , or with melted chocolate, chocolate syrup, or chocolate milk mix...

 has been sold for many years and has been followed more recently by strawberry milk
Strawberry milk
Strawberry milk is a flavored dairy beverage, made either with fresh strawberries mixed with plain milk, strawberry powder, or with a strawberry flavored syrup...

 and others. Some nutritionists have criticized flavored milk for adding sugar, usually in the form of high-fructose corn syrup, to the diets of children who are already commonly obese in the U.S.

Distribution




Due to the short shelf life of normal milk, it used to be delivered to households daily in many countries; however, improved refrigeration at home, changing food shopping patterns because of supermarkets, and the higher cost of home delivery mean that daily deliveries by a milkman
Milkman
A milkman is a person, traditionally male, who delivers milk in milk bottles or cartons. Milk deliveries frequently occur in the morning and it is not uncommon for milkmen to deliver products other than milk such as eggs, cream, cheese, butter, yogurt or soft drinks...

 are no longer available in most countries.

Australia and New Zealand


In Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

, prior to "metrification", milk was generally distributed in 1 pint (568ml) glass bottles. In Australia and in Ireland there was a government funded "free milk for school children" program, and milk was distributed at morning recess in 1/3 pint bottles. With the conversion to metric measures, the milk industry were concerned that the replacement of the pint bottles with 500ml bottles would result in a 13.6% drop in milk consumption; hence, all pint bottles were recalled and replaced by 600 mL bottles. With time, due to the steadily increasing cost of collecting, transporting, storing and cleaning glass bottles, they were replaced by cardboard cartons. A number of designs were used, including a tetrahedron which could be close-packed without waste space, and could not be knocked over accidentally. (slogan: No more crying over spilt milk.) However, the industry eventually settled on a design similar to that used in the United States. Milk is now available in a variety of sizes in cardboard cartons (250 mL, 375 mL, 600 mL, 1 liter and 1.5 liters) and plastic bottles (1, 2 and 3 liters). A significant addition to the marketplace has been "long-life" milk (UHT), generally available in 1 and 2 liter rectangular cardboard cartons. In urban and suburban areas where there is sufficient demand, home delivery is still available, though in suburban areas this is often 3 times per week rather than daily. Another significant and popular addition to the marketplace has been flavoured milks – for example, as mentioned above, Farmers Union Iced Coffee outsells Coca-Cola
Coca-Cola
Coca-Cola is a carbonated soft drink sold in stores, restaurants, and vending machines in more than 200 countries. It is produced by The Coca-Cola Company of Atlanta, Georgia, and is often referred to simply as Coke...

 in South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

.

India


In rural India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, milk is delivered daily by a local milkman carrying bulk quantities in a metal container, usually on a bicycle, and in other parts of metropolitan India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, milk is usually bought or delivered in a plastic bags or cartons via shops or supermarkets.

Pakistan


In Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

, milk is supplied in jugs. Milk has been a staple food, especially among the pastoral tribes in this country.

United Kingdom


Since the late 1990s, milk-buying patterns have changed drastically in the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. The classic milkman
Milkman
A milkman is a person, traditionally male, who delivers milk in milk bottles or cartons. Milk deliveries frequently occur in the morning and it is not uncommon for milkmen to deliver products other than milk such as eggs, cream, cheese, butter, yogurt or soft drinks...

, who travels his local milk round
Milk round
The Milk round is the term commonly used in the UK to describe the phenomenon of companies touring universities each year, in order to advertise their opportunities and recruit students...

 (route) using a milk float
Milk float
A milk float is a battery electric vehicle , specifically designed for the delivery of fresh milk. They were once common in many European countries, particularly the United Kingdom, and were operated by local dairies...

 (often battery powered) during the early hours and delivers milk in 1 pint
Pint
The pint is a unit of volume or capacity that was once used across much of Europe with values varying from state to state from less than half a litre to over one litre. Within continental Europe, the pint was replaced with the metric system during the nineteenth century...

 glass bottles with aluminium foil
Aluminium foil
Aluminium foil is aluminium prepared in thin metal leaves, with a thickness less than , thinner gauges down to are also commonly used. In the USA, foils are commonly gauged in mils. Standard household foil is typically thick and heavy duty household foil is typically .The foil is pliable, and...

 tops directly to households, has almost disappeared.
The main reasons for the decline of U.K. home deliveries by milkmen are household refrigerators (which lessen the need for daily milk deliveries) and private car usage (which has increased supermarket shopping). In 1996, more than 2.5 billion liters of milk were still being delivered by milkmen, but by 2006 only 637 million liters (13% of milk consumed) was delivered by some 9,500 milkmen. By 2010, the estimated number of milkmen had dropped to 6,000. Assuming that delivery per milkman is the same as it was in 2006, this means milkmen deliveries now only account for 6–7% of all milk consumed by U.K. households (6.7 billion liters in 2008/2009).

Almost 95% of all milk in the U.K. is thus sold in shops today, most of it in plastic bottles of various sizes, but some also in milk cartons. Milk is hardly ever sold in glass bottles in U.K. shops.

United States


In the United States, glass milk bottles have been replaced mostly with milk cartons and plastic jugs. Gallons of milk are almost always sold in jugs, while half gallons and quarts may be found in both paper cartons and plastic jugs, and smaller sizes are almost always in cartons.

The 0.5 USpt milk carton is the traditional unit as a component of school lunches, though some companies have replaced that unit size with a plastic bottle, which is also available at retail in 6- and 12-pack size.

Packaging


Glass milk bottles are now rare. Most people purchase milk in bags, plastic bottles, or plastic-coated paper cartons. Ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

 (UV) light from fluorescent lighting
Fluorescent lamp
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful...

 can alter the flavor of milk, so many companies that once distributed milk in transparent
Transparency and translucency
In the field of optics, transparency is the physical property of allowing light to pass through a material; translucency only allows light to pass through diffusely. The opposite property is opacity...

 or highly translucent containers are now using thicker materials that block the UV light.
Milk comes in a variety of containers
Carton
Carton is the name of certain types of containers typically made from paperboard which is also sometimes known as cardboard. Many types of cartons are used in packaging. Sometimes a carton is also called a box.-Folding cartons:...

 with local variants:
  • Australia
    Australia
    Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

     and New Zealand
    New Zealand
    New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

Distributed in a variety of sizes, most commonly in aseptic
Aseptic processing
Aseptic processing is the process by which a sterile product is packaged in a sterile container in a way that maintains sterility...

 cartons for up to 1.5 liters, and plastic screw-top bottles beyond that with the following volumes; 1.1 L, 2 L, and 3 L. 1 liter milk bag
Milk bag
Milk bags are plastic bags that hold milk. They are usually stored in a pitcher or jug with one of the corners cut off to allow for pouring. A typical milk bag contains approximately 1 1/3 litres of milk.- Popularity :...

s are starting to appear in supermarkets, but have not yet proved popular. Most UHT-milk is packed in 1 or 2 liter paper containers with a sealed plastic spout.
  • Brazil
    Brazil
    Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

Used to be sold in cooled 1 liter bags, just like in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

. Today the most common form is 1 liter aseptic cartons containing UHT skimmed, semi-skimmed or whole milk, although the plastic bags are still in use for pasteurized milk. Higher grades of pasteurized milk can be found in cartons or plastic bottles. Sizes other than 1 liter are rare.
  • Canada
    Canada
    Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

1.33 liter plastic bags (sold as 4 liters in 3 bags) are widely available in some areas (especially the Maritimes
Maritimes
The Maritime provinces, also called the Maritimes or the Canadian Maritimes, is a region of Eastern Canada consisting of three provinces, New Brunswick, Nova Scotia, and Prince Edward Island. On the Atlantic coast, the Maritimes are a subregion of Atlantic Canada, which also includes the...

, Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

 and Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

), although the 4 liter plastic jug has supplanted them in western Canada
Western Canada
Western Canada, also referred to as the Western provinces and commonly as the West, is a region of Canada that includes the four provinces west of the province of Ontario.- Provinces :...

. Other common packaging sizes are 2 liter, 1 liter, 500 mL, and 250 mL cartons, as well as 4 liter, 1 liter, 250 mL aseptic cartons and 500 mL plastic jugs.
  • Chile
    Chile
    Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

Distributed most commonly in aseptic
Aseptic processing
Aseptic processing is the process by which a sterile product is packaged in a sterile container in a way that maintains sterility...

 cartons for up to 1 liter, but smaller, snack-sized cartons are also popular. The most common flavors, besides the natural presentation, are chocolate, strawberry and vanilla.
  • China
    China
    Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

Sweetened milk is a drink popular with students of all ages and is often sold in small plastic bags complete with straw. Adults not wishing to drink at a banquet often drink milk served from cartons or milk tea
Hong Kong-style milk tea
Hong Kong-style milk tea is a beverage originating from Hong Kong consisting of black tea with evaporated milk or condensed milk. It is usually part of lunch in Hong Kong tea culture...

.
  • Colombia
    Colombia
    Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...

     sells milk in 1 liter plastic bags.
  • Croatia
    Croatia
    Croatia , officially the Republic of Croatia , is a unitary democratic parliamentary republic in Europe at the crossroads of the Mitteleuropa, the Balkans, and the Mediterranean. Its capital and largest city is Zagreb. The country is divided into 20 counties and the city of Zagreb. Croatia covers ...

    , Bosnia and Herzegovina
    Bosnia and Herzegovina
    Bosnia and Herzegovina , sometimes called Bosnia-Herzegovina or simply Bosnia, is a country in Southern Europe, on the Balkan Peninsula. Bordered by Croatia to the north, west and south, Serbia to the east, and Montenegro to the southeast, Bosnia and Herzegovina is almost landlocked, except for the...

    , Serbia
    Serbia
    Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...

    , Montenegro
    Montenegro
    Montenegro Montenegrin: Crna Gora Црна Гора , meaning "Black Mountain") is a country located in Southeastern Europe. It has a coast on the Adriatic Sea to the south-west and is bordered by Croatia to the west, Bosnia and Herzegovina to the northwest, Serbia to the northeast and Albania to the...

UHT milk (trajno mlijeko/trajno mleko/трајно млеко) is sold in 500 mL and 1 L (sometimes also 200 ml) aseptic cartons. Non-UHT pasteurized milk (svježe mlijeko/sveže mleko/свеже млеко) is most commonly sold in 1 L and 1.5 L PET bottles, though in Serbia one can still find milk in plastic bags.
  • Parts of Europe
    Europe
    Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

Sizes of 500 mL, 1 liter (the most common), 1.5 liters, 2 liters and 3 liters are commonplace.
  • Finland
    Finland
    Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

Commonly sold in 1 L or 1.5 L cartons, in some places also in 2 dl and 5 dl cartons.
  • Hong Kong
    Hong Kong
    Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...

Milk is sold in glass bottles (220 mL), cartons (236 mL and 1 L), plastic jugs (2 liters) and aseptic cartons (250 mL).
  • India
    India
    India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

Commonly sold in 500 mL plastic bags and in bottles in some parts like in west. It is still customary to serve the milk boiled, despite pasteurization. Milk is often buffalo milk. Flavored milk is sold in most convenience stores in waxed cardboard containers. Convenience stores also sell many varieties of milk (such as flavored and ultra-pasteurized) in different sizes, usually in aseptic cartons.
  • Indonesia
    Indonesia
    Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

Usually sold in 1 liter cartons, but smaller, snack-sized cartons are available.
  • Israel
    Israel
    The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

Non-UHT milk is most commonly sold in 1 liter waxed cardboard boxes and 1 liter plastic bags. It may also be found in 0.5 L and 2 L waxed cardboard boxes, 2 L plastic jugs and 1 L plastic bottles. UHT milk is available in 1 liter (and less commonly also in 0.25 L) carton "bricks".
  • Japan
    Japan
    Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

Commonly sold in 1 liter waxed paperboard cartons. In most city centers there is also home delivery
Delivery (commerce)
Delivery is the process of transporting goods. Most goods are delivered through a transportation network. Cargo are primarily delivered via roads and railroads on land, shipping lanes on the sea and airline networks in the air...

 of milk in glass jugs. As seen in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

, sweetened and flavored milk drinks are commonly seen in vending machine
Vending machine
A vending machine is a machine which dispenses items such as snacks, beverages, alcohol, cigarettes, lottery tickets, consumer products and even gold and gems to customers automatically, after the customer inserts currency or credit into the machine....

s.
  • South Korea
    South Korea
    The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...

Sold in cartons (180 mL, 200 mL, 500 mL 900 mL, 1 L, 1.8 L, 2.3 L), plastic jugs (1 L and 1.8 L), aseptic cartons (180 mL and 200 mL) and plastic bags (1 L).
  • Pakistan
    Pakistan
    Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

Milk is supplied in 500 mL Plastic bags and carried in Jugs from rural to cities and sell
  • Poland
    Poland
    Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

UHT milk is mostly sold in aseptic cartons (500 mL, 1 L, 2 L), and non-UHT in 1 L plastic bags or plastic bottles. Milk, UHT is commonly boiled, despite being pasteurized.
  • South Africa
    South Africa
    The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

Commonly sold in 1 liter bags. The bag is then placed in a plastic jug and the corner cut off before the milk is poured.
  • Sweden
    Sweden
    Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

Commonly sold in 0.3 L, 1 L or 1.5 L cartons and sometimes as plastic or glass milk bottles.
  • Turkey
    Turkey
    Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

Commonly sold in 500 mL or 1L cartons or special plastic bottles. UHT milk is more popular. Milkmen also serve in smaller towns and villages.
  • United Kingdom
    United Kingdom
    The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

Most stores stock imperial sizes: 1 pint (568 mL, 2 pints (1.136 L), 4 pints (2.273 L), 6 pints (3.408 L) or a combination including both metric and imperial sizes. Glass milk bottles delivered to the doorstep by the milkman are typically pint-sized and are returned empty by the householder for repeated reuse
Reuse
To reuse is to use an item more than once. This includes conventional reuse where the item is used again for the same function, and new-life reuse where it is used for a different function. In contrast, recycling is the breaking down of the used item into raw materials which are used to make new...

. Milk is sold at supermarkets in either aseptic cartons or HDPE bottles. Supermarkets have also now begun to introduce milk in bags, to be poured from a proprietary jug and nozzle.
  • United States
    United States
    The United States of America is a federal constitutional republic comprising fifty states and a federal district...

Commonly sold in gallon
Gallon
The gallon is a measure of volume. Historically it has had many different definitions, but there are three definitions in current use: the imperial gallon which is used in the United Kingdom and semi-officially within Canada, the United States liquid gallon and the lesser used United States dry...

 (3.78 L), half-gallon (1.89 L) and quart
Quart
The quart is a unit of volume equal to a quarter of a gallon, two pints, or four cups. Since gallons of various sizes have historically been in use, quarts of various sizes have also existed; see gallon for further discussion. Three of these kinds of quarts remain in current use, all approximately...

 (0.94 L) containers of natural-colored HDPE resin, or, for sizes less than one gallon, cartons of waxed paperboard. Bottles made of opaque PET
Polyethylene terephthalate
Polyethylene terephthalate , commonly abbreviated PET, PETE, or the obsolete PETP or PET-P, is a thermoplastic polymer resin of the polyester family and is used in synthetic fibers; beverage, food and other liquid containers; thermoforming applications; and engineering resins often in combination...

 are also becoming commonplace for smaller, particularly metric, sizes such as one liter. The US single-serving size is usually the half-pint (about 240 mL). Less frequently, dairies deliver milk directly to consumers, from coolers filled with glass bottles which are typically half-gallon sized and returned for reuse. Some convenience store
Convenience store
A convenience store, corner store, corner shop, commonly called a bodega in Spanish-speaking areas of the United States, is a small store or shop in a built up area that stocks a range of everyday items such as groceries, toiletries, alcoholic and soft drinks, and may also offer money order and...

 chains in the United States (such as Kwik Trip
Kwik Trip
Kwik Trip/Kwik Star is a chain of convenience stores founded in 1965 with locations throughout Wisconsin and Minnesota under the name Kwik Trip, and in northeast Iowa under the name Kwik Star . The company also operates stores under the name Hearty Platter and Tobacco Outlet Plus. Kwik Trip, Inc...

 in the Midwest) sell milk in half-gallon bags, while another rectangular cube gallon container design
Square milk jug
The square milk jug is a variant of the plastic gallon container of milk commonly sold in the United States and Canada. The design was introduced in the summer of 2008 and is marketed as environmentally friendly because of the shape's advantages for shipping and storage . Square milk jugs are...

 used for easy stacking in shipping and displaying is used by warehouse club
Warehouse club
A warehouse club is a retail store, usually selling a wide variety of merchandise, in which customers are required to buy large, wholesale quantities of the store's products, which makes these clubs attractive to both bargain hunters and small business owners. The clubs are able to keep prices low...

s such as Costco
Costco
Costco Wholesale Corporation is the largest membership warehouse club chain in the United States. it is the third largest retailer in the United States, where it originated, and the ninth largest in the world...

 and Sam's Club
Sam's Club
Sam's Club is a chain of membership-only retail warehouse clubs owned and operated by Wal-Mart Stores, Inc., founded in 1983 and named after Wal-Mart founder Sam Walton. , the Sam's Club chain serves more than 47 million U.S. members...

, along with some Wal-Mart
Wal-Mart
Wal-Mart Stores, Inc. , branded as Walmart since 2008 and Wal-Mart before then, is an American public multinational corporation that runs chains of large discount department stores and warehouse stores. The company is the world's 18th largest public corporation, according to the Forbes Global 2000...

 stores.
  • Uruguay
    Uruguay
    Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

Commonly sold in 1 liter bags. The bag is then placed in a plastic jug and the corner cut off before the milk is poured.


Practically everywhere, condensed milk
Condensed milk
Condensed milk, also known as sweetened condensed milk, is cow's milk from which water has been removed and to which sugar has been added, yielding a very thick, sweet product which when canned can last for years without refrigeration if unopened. The two terms, condensed milk and sweetened...

 and evaporated milk are distributed in metal cans, 250 and 125 mL paper containers and 100 and 200 mL squeeze tubes, and powdered milk
Powdered milk
Powdered milk is a manufactured dairy product made by evaporating milk to dryness. One purpose of drying milk is to preserve it; milk powder has a far longer shelf life than liquid milk and does not need to be refrigerated, due to its low moisture content. Another purpose is to reduce its bulk for...

 (skim and whole) is distributed in boxes or bags.

Spoilage and fermented milk products


When raw milk
Raw milk
Raw milk is milk that has not been pasteurized or homogenized.-History:Humans consumed raw milk exclusively prior to the industrial revolution and the invention of the pasteurization process in 1864. During the industrial revolution large populations congregated into urban areas detached from the...

 is left standing for a while, it turns "sour". This is the result of fermentation
Fermentation (food)
Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions. Fermentation in simple terms is the chemical conversion of sugars into ethanol...

, where lactic acid bacteria
Lactic acid bacteria
The lactic acid bacteria comprise a clade of Gram-positive, low-GC, acid-tolerant, generally non-sporulating, non-respiring rod or cocci that are associated by their common metabolic and physiological characteristics. These bacteria, usually found in decomposing plants and lactic products, produce...

 ferment the lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...

 in the milk into lactic acid
Lactic acid
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...

. Prolonged fermentation may render the milk unpleasant to consume. This fermentation process is exploited by the introduction of bacterial cultures (e.g. Lactobacilli sp., Streptococcus
Streptococcus
Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...

 sp., Leuconostoc
Leuconostoc
Leuconostoc is a genus of Gram-positive bacteria, placed within the family of Leuconostocaceae. They are generally ovoid cocci often forming chains. Leuconostoc spp. are intrinsically resistant to vancomycin and are catalase-negative . All species within this genus are heterofermentative and are...

 sp.
, etc.) to produce a variety of fermented milk products
Fermented milk products
Fermented milk products, also known as cultured dairy foods, cultured dairy products, or cultured milk products, are dairy foods that have been fermented with lactic acid bacteria such as Lactobacillus, Lactococcus, and Leuconostoc...

. The reduced pH from lactic acid accumulation denatures proteins and causes the milk to undergo a variety of different transformations in appearance and texture, ranging from an aggregate to smooth consistency. Some of these products include sour cream
Sour cream
Sour cream is a dairy product rich in fats obtained by fermenting a regular cream by certain kinds of lactic acid bacteria. The bacterial culture, which is introduced either deliberately or naturally, sours and thickens the cream. Its name stems from the production of lactic acid by bacterial...

, yoghurt
Yoghurt
Yoghurt, yogurt or yogourt is a dairy product produced by bacterial fermentation of milk. The bacteria used to make yoghurt are known as "yoghurt cultures"...

, cheese
Cheese
Cheese is a generic term for a diverse group of milk-based food products. Cheese is produced throughout the world in wide-ranging flavors, textures, and forms....

, buttermilk
Buttermilk
Buttermilk refers to a number of dairy drinks. Originally, buttermilk was the liquid left behind after churning butter out of cream. It also refers to a range of fermented milk drinks, common in warm climates where unrefrigerated fresh milk otherwise sours quickly...

, viili
Viili
Viili is a type of yoghurt that originated in the Nordic countries. It has a ropey, gelatinous consistency and a pleasantly mild taste resulting from lactic acid...

, kefir
Kefir
Kefir is a fermented milk drink that originated with shepherds of the North Caucasus region, who discovered that fresh milk carried in leather pouches would occasionally ferment into an effervescent beverage...

, and kumis
Kumis
Kumis, also spelled kumiss or koumiss in English is a fermented dairy product traditionally made from mare's milk. The drink remains important to the peoples of the Central Asian steppes, of Turkic and Mongol origin: Bashkirs, Kazakhs, Kyrgyz, Yakuts, Mongols and Kalmyks...

. See Dairy product
Dairy product
Dairy products are generally defined as foods produced from cow's or domestic buffalo's milk. They are usually high-energy-yielding food products. A production plant for such processing is called a dairy or a dairy factory. Raw milk for processing comes mainly from cows, and, to a lesser extent,...

for more information.

Pasteurization
Pasteurization
Pasteurization is a process of heating a food, usually liquid, to a specific temperature for a definite length of time, and then cooling it immediately. This process slows microbial growth in food...

 of cow's milk initially destroys any potential pathogens and increases the shelf life, but eventually results in spoilage that makes it unsuitable for consumption. This causes it to assume an unpleasant odor, and the milk is deemed non-consumable due to unpleasant taste and an increased risk of food poisoning. In raw milk, the presence of lactic acid
Lactic acid
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...

-producing bacteria, under suitable conditions, ferments the lactose present to lactic acid. The increasing acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

ity in turn prevents the growth of other organisms, or slows their growth significantly. During pasteurization, however, these lactic acid bacteria are mostly destroyed.

In order to prevent spoilage, milk can be kept refrigerated
Refrigerator
A refrigerator is a common household appliance that consists of a thermally insulated compartment and a heat pump that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room...

 and stored between 1 and 4 degrees Celsius in bulk tank
Bulk tank
In dairy farming a bulk milk cooling tank is a large storage tank for cooling and holding milk at a cold temperature until it can be picked up by a milk hauler....

s. Most milk is pasteurized by heating briefly and then refrigerated
Refrigerator
A refrigerator is a common household appliance that consists of a thermally insulated compartment and a heat pump that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room...

 to allow transport from factory farms
Factory farming
Factory farming is a term referring to the process of raising livestock in confinement at high stocking density, where a farm operates as a factory — a practice typical in industrial farming by agribusinesses. The main products of this industry are meat, milk and eggs for human consumption...

 to local markets. The spoilage of milk can be forestalled by using ultra-high temperature (UHT) treatment. Milk so treated can be stored unrefrigerated for several months until opened but has a characteristic "cooked" taste. Condensed milk
Condensed milk
Condensed milk, also known as sweetened condensed milk, is cow's milk from which water has been removed and to which sugar has been added, yielding a very thick, sweet product which when canned can last for years without refrigeration if unopened. The two terms, condensed milk and sweetened...

, made by removing most of the water, can be stored in cans for many years, unrefrigerated, as can evaporated milk
Evaporated milk
Evaporated milk, also known as dehydrated milk, is a shelf-stable canned milk product with about 60% of the water removed from fresh milk. It differs from sweetened condensed milk, which contains added sugar. Sweetened condensed milk requires less processing since the added sugar inhibits ...

. The most durable form of milk is powdered milk
Powdered milk
Powdered milk is a manufactured dairy product made by evaporating milk to dryness. One purpose of drying milk is to preserve it; milk powder has a far longer shelf life than liquid milk and does not need to be refrigerated, due to its low moisture content. Another purpose is to reduce its bulk for...

, which is produced from milk by removing almost all water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

. The moisture content is usually less than 5% in both drum- and spray-dried powdered milk.

Language and culture


The importance of milk in human culture is attested to by the numerous expressions embedded in our languages, for example, "the milk of human kindness". In ancient Greek mythology
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...

, the goddess
Goddess
A goddess is a female deity. In some cultures goddesses are associated with Earth, motherhood, love, and the household. In other cultures, goddesses also rule over war, death, and destruction as well as healing....

 Hera
Hera
Hera was the wife and one of three sisters of Zeus in the Olympian pantheon of Greek mythology and religion. Her chief function was as the goddess of women and marriage. Her counterpart in the religion of ancient Rome was Juno. The cow and the peacock were sacred to her...

 spilled her breast
Breast
The breast is the upper ventral region of the torso of a primate, in left and right sides, which in a female contains the mammary gland that secretes milk used to feed infants.Both men and women develop breasts from the same embryological tissues...

 milk after refusing to feed Heracles
Heracles
Heracles ,born Alcaeus or Alcides , was a divine hero in Greek mythology, the son of Zeus and Alcmene, foster son of Amphitryon and great-grandson of Perseus...

, resulting in the Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...

.

In Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

n and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

n developing nations
Developing country
A developing country, also known as a less-developed country, is a nation with a low level of material well-being. Since no single definition of the term developing country is recognized internationally, the levels of development may vary widely within so-called developing countries...

, butter
Butter
Butter is a dairy product made by churning fresh or fermented cream or milk. It is generally used as a spread and a condiment, as well as in cooking applications, such as baking, sauce making, and pan frying...

 is traditionally made from fermented milk rather than cream. It can take several hours of churning to produce workable butter grains from fermented milk.

Holy books have also mentioned milk. The Bible contains references to the 'Land of Milk and Honey
Land of Israel
The Land of Israel is the Biblical name for the territory roughly corresponding to the area encompassed by the Southern Levant, also known as Canaan and Palestine, Promised Land and Holy Land. The belief that the area is a God-given homeland of the Jewish people is based on the narrative of the...

'. In the Qur'an
Qur'an
The Quran , also transliterated Qur'an, Koran, Alcoran, Qur’ān, Coran, Kuran, and al-Qur’ān, is the central religious text of Islam, which Muslims consider the verbatim word of God . It is regarded widely as the finest piece of literature in the Arabic language...

, there is a request to wonder on milk as follows: 'And surely in the livestock there is a lesson for you, We give you to drink of that which is in their bellies from the midst of digested food and blood, pure milk palatable for the drinkers.'(16-The Honeybee, 66). The Ramadhan fast is traditionally broken with a glass of milk and dates.

To milk someone, in the vernacular of many English-speaking countries, is to take advantage of the person.

The word "milk" has had many slang meanings over time. In the early 17th century the word was used to mean semen, or vaginal secretions, or to masturbate oneself or someone else. In the 19th century, milk was used to describe a cheap alcoholic drink made from methylated spirits mixed with water. The word was also used to mean defraud, to be idle, to intercept telegrams addressed to someone else, and a weakling or 'milksop'. In the mid 1930s, the word was used in Australia meaning to siphon gas from a car.


Milk is sometimes referred to as moo juice in American English, while Cockney rhyming slang calls it Acker Bilk, Tom Silk, Lady in silk and Kilroy Silk
Robert Kilroy-Silk
Robert Michael Kilroy-Silk is an English former politician, former independent Member of the European Parliament, and former television presenter, best known for his daytime talk show Kilroy. He has been a university lecturer and Labour Party Member of Parliament...

.

The name of the Russian Molokan
Molokan
Molokans are sectarian Christians who evolved from "Spiritual Christian" Russian peasants that refused to obey the Russian Orthodox Church, beginning in the 17th century...

 (Russian: "Молока́не") religion in Russian is derived from Russian "Молоко́ " meaning "Milk" as they would drink milk on the Russian Orthodox days of fast.

Other uses


Besides serving as a beverage or source of food, milk has been described as used by farmers and gardeners as an organic fungicide
Fungicide
Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality and profit. Fungicides are used both in agriculture and to fight fungal infections in animals...

 and foliage fertilizer. Diluted milk solutions have been demonstrated to provide an effective method of preventing powdery mildew on grape vines, while showing it is unlikely to harm the plant.

See also



  • Babcock test
    Babcock test
    The Babcock test is the first inexpensive and practical test factories could use to determine the fat content of milk.-Motivation:Until the 1890s, dishonest farmers could water down their milk or remove some cream before selling it to the factories because milk was paid for by volume...

     (determines the butterfat content of milk)
  • Casein paint
    Casein paint
    Casein paint, derived from milk casein, is a fast-drying, water-soluble medium used by artists. It generally has a glue-like consistency, but can be thinned with water to the degree that fits a particular artist's style and desired result. It can be used on canvas panels, illustration boards,...

  • Got Milk?
    Got Milk?
    Got Milk? is an American advertising campaign encouraging the consumption of cow's milk, which was created by the advertising agency Goodby Silverstein & Partners for the California Milk Processor Board in 1993 and later licensed for use by milk processors and dairy farmers. It has been running...

     (US milk lobby advertising campaign encouraging the consumption of milk)
  • Grain milk
    Grain milk
    thumb|right|250px|Rice milk as sold in Germany .Grain milk is a milk substitute made from fermented grain or from flour. Grain milk can be made from oats, spelt, rice, rye, einkorn wheat or quinoa.Grain milk looks very similar to cow's milk...

  • Health mark
    Health mark
    Health mark is the official name of an oval-shaped symbol found on milk and meat products required by European Community food safety laws. It identifies the processing establishment that produced and packaged the product and that is therefore responsible for its hygiene status...


  • Male lactation
    Male lactation
    Male lactation in zoology means production of milk from mammary glands in the presence of physiological stimuli connected with nursing infants. It is well documented in the Dayak fruit bat.The term male lactation is not used in human medicine...

  • Milk line
    Milk line
    The milk lines are two parallel lines, formed by thickenings of the epidermis along the ventral surface of mammals of both sexes. They extend from the upper limbs to the lower limbs and are developed in the embryo...

  • Milk paint
    Milk paint
    Milk paint is a non-toxic water based mixture used as a paint. It is made from milk and lime with or without pigments added for color. Borax may be added to the milk paint recipe to assist the lime in dissolving the casein and as a preservative....

  • Nipple
    Nipple
    In its most general form, a nipple is a structure from which a fluid emanates. More specifically, it is the projection on the breasts or udder of a mammal by which breast milk is delivered to a mother's young. In this sense, it is often called a teat, especially when referring to non-humans, and...

  • Operation Flood
    Operation Flood
    Operation Flood was a rural development programme started by India's National Dairy Development Board in 1970. One of the largest of its kind, the programme objective was to create a nationwide milk grid....

  • Milk bottle top
    Milk bottle top
    A milk bottle top is a lid to a milk bottle. They are usually colour-coded to show the consumer the different varieties of milk, especially the flavour or fat content...

  • Fat content of milk
    Fat content of milk
    The fat content of milk is the proportion of milk, by weight,made up by butterfat. The fat content, particularly of cow's milk, is modified to make a variety of products...



External links