Milk is a nutrient-rich, white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for infant mammals (including humans who are breastfed) before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to its young and can reduce the risk of many diseases. It contains many other nutrients[1] including protein and lactose. Interspecies consumption of milk is not uncommon, particularly among humans, many of whom consume the milk of other mammals.[2][3]
As an agricultural product, milk, also called dairy milk, is extracted from farm animals during or soon after pregnancy. Dairy farms produced about 730 million tonnes of milk in 2011,[4] from 260 million dairy cows.[5] India is the world's largest producer of milk, and is the leading exporter of skimmed milk powder, yet it exports few other milk products.[6][7] The ever increasing rise in domestic demand for dairy products and a large demand-supply gap could lead to India being a net importer of dairy products in the future.[8] The United States, India, China and Brazil are the world's largest exporters of milk and milk products.[9] China and Russia were the world's largest importers of milk and milk products until 2016 when both countries became self-sufficient, contributing to a worldwide glut of milk.[10]
Throughout the world, more than six billion people consume milk and milk products. Over 750 million people live in dairy farming households.[11]
Etymology
The term "milk" comes from "Old English meoluc (West Saxon), milc (Anglian), from Proto-Germanic *meluks "milk" (source also of Old Norse mjolk, Old Frisian melok, Old Saxon miluk, Dutch melk, Old High German miluh, German Milch, Gothic miluks)".[12]
Types of consumption
Milk consumption occurs in two distinct overall types: a natural source of nutrition for all infant mammals and a food product obtained from other mammals for consumption by humans of all ages.
Nutrition for infant mammals

In almost all mammals, milk is fed to infants through breastfeeding, either directly or by expressing the milk to be stored and consumed later. The early milk from mammals is called colostrum. Colostrum contains antibodies that provide protection to the newborn baby as well as nutrients and growth factors.[13] The makeup of the colostrum and the period of secretion varies from species to species.[14]
For humans, the World Health Organization recommends exclusive breastfeeding for six months and breastfeeding in addition to other food for at least two years.[15] In some cultures it is common to breastfeed children for three to five years, and the period may be longer.[16]
Fresh goats' milk is sometimes substituted for breast milk, which introduces the risk of the child developing electrolyte imbalances, metabolic acidosis, megaloblastic anemia, and a host of allergic reactions.[17]
Food product for humans

In many cultures, especially in the West, humans continue to consume milk beyond infancy, using the milk of other mammals (especially cattle, goats and sheep) as a food product. Initially, the ability to digest milk was limited to children as adults did not produce lactase, an enzyme necessary for digesting the lactose in milk. People therefore converted milk to curd, cheese and other products to reduce the levels of lactose. Thousands of years ago, a chance mutation spread in human populations in Europe that enabled the production of lactase in adulthood. This mutation allowed milk to be used as a new source of nutrition which could sustain populations when other food sources failed.[18] Milk is processed into a variety of products such as cream, butter, yogurt, kefir, ice cream, and cheese. Modern industrial processes use milk to produce casein, whey protein, lactose, condensed milk, powdered milk, and many other food-additives and industrial products.
Whole milk, butter and cream have high levels of saturated fat.[19][20] The sugar lactose is found only in milk, forsythia flowers, and a few tropical shrubs. The enzyme needed to digest lactose, lactase, reaches its highest levels in the human small intestine after birth and then begins a slow decline unless milk is consumed regularly.[21] Those groups who do continue to tolerate milk, however, often have exercised great creativity in using the milk of domesticated ungulates, not only of cattle, but also sheep, goats, yaks, water buffalo, horses, reindeer and camels. India is the largest producer and consumer of cattle and buffalo milk in the world.[22]

Terminology
In food use, from 1961, the term milk has been defined under Codex Alimentarius standards as: "the normal mammary secretion of milking animals obtained from one or more milkings without either addition to it or extraction from it, intended for consumption as liquid milk or for further processing."[24] The term dairy relates to animal milk and animal milk production.
A substance secreted by pigeons to feed their young is called "crop milk" and bears some resemblance to mammalian milk, although it is not consumed as a milk substitute.[25]
Dairy milk alternatives
The definition above precludes non-animal products which resemble dairy milk in color and texture, such as almond milk, coconut milk, rice milk, and soy milk. In English, the word "milk" has been used to refer to "milk-like plant juices" since 1200 AD.[26] In the USA, (mostly plant-based) milk alternatives now command 13% of the "milk" market, leading the US dairy industry to attempt, multiple times, to sue producers of dairy milk alternatives, to have the name "milk" limited to animal milk, so far without success.[27]
Evolution of lactation
The mammary gland is thought to have derived from apocrine skin glands.[28] It has been suggested that the original function of lactation (milk production) was keeping eggs moist. Much of the argument is based on monotremes (egg-laying mammals).[28][29][30] The original adaptive significance of milk secretions may have been nutrition[31] or immunological protection.[32][33] This secretion gradually became more copious and accrued nutritional complexity over evolutionary time.[28]
Tritylodontid cynodonts seem to have displayed lactation, based on their dental replacement patterns.[34]
History

Humans first learned to consume the milk of other mammals regularly following the domestication of animals during the Neolithic Revolution or the development of agriculture. This development occurred independently in several global locations from as early as 9000–7000 BC in Mesopotamia[35] to 3500–3000 BC in the Americas.[36] People first domesticated the most important dairy animals– cattle, sheep and goats– in Southwest Asia, although domestic cattle had been independently derived from wild aurochs populations several times since.[37]  Initially animals were kept for meat, and archaeologist Andrew Sherratt has suggested that dairying, along with the exploitation of domestic animals for hair and labor, began much later in a separate secondary products revolution in the fourth millennium BC.[38] Sherratt's model is not supported by recent findings, based on the analysis of lipid residue in prehistoric pottery, that shows that dairying was practiced in the early phases of agriculture in Southwest Asia, by at least the seventh millennium BC.[39][40]
From Southwest Asia domestic dairy animals spread to Europe (beginning around 7000 BC but did not reach Britain and Scandinavia until after 4000 BC),[41] and South Asia (7000–5500 BC).[42] The first farmers in central Europe[43] and Britain[44] milked their animals. Pastoral and pastoral nomadic 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 in the fourth millennium BC, and subsequently spread across much of the Eurasian steppe.[45] Sheep and goats were introduced to Africa from Southwest Asia, but African cattle may have been independently domesticated around 7000–6000 BC.[46] Camels, domesticated in central Arabia in the fourth millennium BC, have also been used as dairy animals in North Africa and the Arabian Peninsula.[47] The earliest Egyptian records of burn treatments describe burn dressings using milk from mothers of male babies.[48] 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 and political domination over much of the world in the last 500 years.
In the Middle Ages, milk was called the "virtuous white liquor" because alcoholic beverages were safer to consume than water.[49]
Industrialization

The growth in urban population, coupled with the expansion of the railway network in the mid-19th century, brought about a revolution in milk production and supply. Individual railway firms began transporting milk from rural areas to London from the 1840s and 1850s. Possibly the first such instance was in 1846, when St Thomas's Hospital in Southwark contracted with milk suppliers outside London to ship milk by rail.[50] The Great Western Railway was an early and enthusiastic adopter, and began to transport milk into London from Maidenhead in 1860, despite much criticism. By 1900, the company was transporting over 25 million gallons annually.[51] The milk trade grew slowly through the 1860s, but went through a period of extensive, structural change in the 1870s and 1880s.

Urban demand began to grow, as consumer purchasing power increased and milk became regarded as a required daily commodity. Over the last three decades of the 19th century, demand for milk in most parts of the country doubled, or in some cases, tripled. Legislation in 1875 made the adulteration of milk illegal – this combined with a marketing campaign to change the image of milk. The proportion of rural imports by rail as a percentage of total milk consumption in London grew from under 5% in the 1860s to over 96% by the early 20th century. By that point, the supply system for milk was the most highly organized and integrated of any food product.[50]

The first glass bottle packaging for milk was used in the 1870s. The first company to do so may have been the New York Dairy Company in 1877. The Express Dairy Company in England began glass bottle production in 1880. In 1884, Hervey Thatcher, an American inventor from New York, invented a glass milk bottle, called "Thatcher's Common Sense Milk Jar," which was sealed with a waxed paper disk.[52] Later, in 1932, plastic-coated paper milk cartons were introduced commercially.[52]
In 1863, French chemist and biologist Louis Pasteur invented pasteurization, a method of killing harmful bacteria in beverages and food products.[52] He developed this method while on summer vacation in Arbois, to remedy the frequent acidity of the local wines.[53] He found out experimentally that it is sufficient to heat a young wine to only about 50–60°C (122–140°F) for a brief time to kill the microbes, and that the wine could be nevertheless properly aged without sacrificing the final quality.[53] In honor of Pasteur, the process became known as "pasteurization". Pasteurization was originally used as a way of preventing wine and beer from souring.[54] Commercial pasteurizing equipment was produced in Germany in the 1880s, and producers adopted the process in Copenhagen and Stockholm by 1885.[55][56]
Overproduction
Continued improvements in the efficiency of milk production led to a worldwide glut of milk by 2016. Russia and China became self-sufficient and stopped importing milk. Canada has tried to restrict milk production by forcing new farmers/increased capacity to "buy in" at C$24,000 per cow. Importing milk is prohibited. The European Union theoretically stopped subsidizing dairy farming in 2015. Direct subsidies were replaced by "environmental incentives" which results in the government buying milk when the price falls to €200 per 1,000 liters (220impgal; 260U.S.gal). The United States has a voluntary insurance program that pays farmers depending upon the price of milk and the cost of feed.[10]
Sources

The females of all mammal species can by definition produce milk, but cow's milk dominates commercial production. In 2011, FAO estimates 85% of all milk worldwide was produced from cows.[57] Human milk is not produced or distributed industrially or commercially; however, human milk banks collect donated human breastmilk and redistribute it to infants who may benefit from human milk for various reasons (premature neonates, babies with allergies, metabolic diseases, etc.) but who cannot breastfeed.[58]
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 using automated milking equipment produces the vast majority of milk in developed countries. Dairy cattle such as the Holstein have been bred selectively for increased milk production. About 90% of the dairy cows in the United States and 85% in Great Britain are Holsteins.[21] Other dairy cows in the United States include Ayrshire, Brown Swiss, Guernsey, Jersey and Milking Shorthorn (Dairy Shorthorn).
Other animal-based sources

Aside from cattle, many kinds of livestock provide milk used by humans for dairy products. These animals include buffalo, goat, sheep, camel, donkey, horse, reindeer and yak. The first four respectively produced about 11%, 2%, 1.4% and 0.2% of all milk worldwide in 2011.[57]
In Russia and Sweden, small moose dairies also exist.[59]
According to the U.S. National Bison Association, American bison (also called American buffalo) are not milked commercially;[60] 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[61] and during the development of commercial Beefalo in the 1970s and 1980s.[62]
Swine are almost never milked, even though their milk is similar to cow's milk and perfectly suitable for human consumption. The main reasons for this are that milking a sow's numerous small teats is very cumbersome, and that sows can not store their milk as cows can.[63] A few pig farms do sell pig cheese as a novelty item; these cheeses are exceedingly expensive.[64]
Production worldwide

In 2012, the largest producer of milk and milk products was India followed by the United States of America, China, Pakistan and Brazil.[69] All 28 European Union members together produced 153.8 million tonnes of milk in 2013, the largest by any politico-economic union.[70]
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 investments by multinational dairy firms. Nevertheless, in many countries production remains on a small scale and presents significant opportunities for diversification of income sources by small farms.[71] 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 basis, particularly in countries such as India.[72]
Production yields

FAO reports[57] Israel dairy farms are the most productive in the world, with a yield of 12,546 kilograms (27,659lb) milk per cow per year. This survey over 2001 and 2007 was conducted by ICAR (International Committee for Animal Recording)[73] across 17 developed countries. The survey found that the average herd size in these developed countries increased from 74 to 99 cows per herd between 2001 and 2007. A dairy farm had an average of 19 cows per herd in Norway, and 337 in New Zealand. Annual milk production in the same period increased from 7,726 to 8,550kg (17,033 to 18,850lb) per cow in these developed countries. The lowest average production was in New Zealand at 3,974kg (8,761lb) per cow. The milk yield per cow depended on production systems, nutrition of the cows, and only to a minor extent different genetic potential of the animals. What the cow ate made the most impact on the production obtained. New Zealand cows with the lowest yield per year grazed all year, in contrast to Israel with the highest yield where the cows ate in barns with an energy-rich mixed diet.
The milk yield per cow in the United States, the world's largest cow milk producer, was 9,954kg (21,945lb) per year in 2010. In contrast, the milk yields per cow in India and China – the second and third largest producers – were respectively 1,154kg (2,544lb) and 2,282kg (5,031lb) per year.[74]
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.[75] In 2010 the Department of Agriculture predicted farmers would receive an average of $1.35 per U.S. gallon of cow's milk (35 cents per liter), which is down 30 cents per gallon from 2007 and below the break-even point for many cattle farmers.[76]
Physical and chemical properties

Milk is an emulsion or colloid of butterfat globules within a water-based fluid that contains dissolved carbohydrates and protein aggregates with minerals.[77] Because it is produced as a food source for the young, all of its contents provide benefits for growth. The principal requirements are energy (lipids, lactose, and protein), biosynthesis of non-essential amino acids supplied by proteins (essential amino acids and amino groups), essential fatty acids, vitamins and inorganic elements, and water.[78]
pH
The pH of milk ranges from 6.4 to 6.8 and it changes over time. Milk from other bovines and non-bovine mammals varies in composition, but has a similar pH.
Lipids

Initially milk fat is secreted in the form of a fat globule surrounded by a membrane.[79] Each fat globule is composed almost entirely of triacylglycerols and is surrounded by a membrane consisting of complex lipids such as phospholipids, along with proteins. These act as emulsifiers which keep the individual globules from coalescing and protect the contents of these globules from various enzymes in the fluid portion of the milk. Although 97–98% of lipids are triacylglycerols, small amounts of di- and monoacylglycerols, free cholesterol and cholesterol esters, free fatty acids, and phospholipids are also present. Unlike protein and carbohydrates, fat composition in milk varies widely in the composition due to genetic, lactational, and nutritional factor difference between different species.[79]
Like composition, fat globules vary in size from less than 0.2 to about 15 micrometers in diameter between different species. Diameter may also vary between animals within a species and at different times within a milking of a single animal. In unhomogenized cow's milk, the fat globules have an average diameter of two to four micrometers and with homogenization, average around 0.4 micrometers.[79] The fat-soluble vitamins A, D, E, and K along with essential fatty acids such as linoleic and linolenic acid are found within the milk fat portion of the milk.[21]
Proteins
Normal bovine milk contains 30–35grams of protein per liter of which about 80% is arranged in casein micelles. Total proteins in milk represent 3.2% of its composition (nutrition table).
Caseins

The largest structures in the fluid portion of the milk are "casein micelles": aggregates of several thousand protein molecules with superficial resemblance to a surfactant micelle, bonded with the help of nanometer-scale particles of calcium phosphate. Each casein micelle is roughly spherical and about a tenth of a micrometer across. There are four different types of casein proteins: αs1-, αs2-, β-, and κ-caseins. Collectively, they make up around 76–86%[78] 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, 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 colloidal suspension in the water-based surrounding fluid.[21][80]
Milk contains dozens of other types of proteins beside caseins and including enzymes. These other proteins are more water-soluble than caseins and do not form larger structures. Because the proteins remain suspended in whey remaining when 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.[21]
Salts, minerals, and vitamins
Minerals or milk salts, are traditional names for a variety of cations and anions within bovine milk. Calcium, phosphate, magnesium, sodium, potassium, citrate, and chloride are all included as minerals and they typically occur at concentration of 5–40 mM. The milk salts strongly interact with casein, most notably calcium phosphate. It is present in excess and often, much greater excess of solubility of solid calcium phosphate.[78] In addition to calcium, milk is a good source of many other vitamins. Vitamins A, B6, B12, C, D, K, E, thiamine, niacin, biotin, riboflavin, folates, and pantothenic acid are all present in milk.
Calcium phosphate structure
For many years the most accepted theory of the structure of a micelle was that it was composed of spherical casein aggregates, called submicelles, that were held together by calcium phosphate linkages. However, there are two recent models of the casein micelle that refute the distinct micellular structures within the micelle.
The first theory attributed to de Kruif and Holt, proposes that nanoclusters of calcium phosphate and the phosphopeptide fraction of beta-casein are the centerpiece to micellular structure. Specifically in this view, unstructured proteins organize around the calcium phosphate giving rise to their structure and thus no specific structure is formed.
The second theory proposed by Horne, the growth of calcium phosphate nanoclusters begins the process of micelle formation but is limited by binding phosphopeptide loop regions of the caseins. Once bound, protein-protein interactions are formed and polymerization occurs, in which K-casein is used as an end cap, to form micelles with trapped calcium phosphate nanoclusters.
Some sources indicate that the trapped calcium phosphate is in the form of Ca9(PO4)6;
whereas, others say it is similar to the structure of the mineral brushite CaHPO4 -2H2O.[81]
Sugars and carbohydrates

Milk contains several different carbohydrate including lactose, glucose, galactose, and other oligosaccharides. The lactose 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, glucose and galactose. Bovine milk averages 4.8% anhydrous lactose, which amounts to about 50% of the total solids of skimmed milk. Levels of lactose are dependent upon the type of milk as other carbohydrates can be present at higher concentrations than lactose in milks.[78]
Miscellaneous contents
Other components found in raw cow's milk are living white blood cells, mammary gland cells, various bacteria, and a large number of active enzymes.[21]
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 and Jersey cattle) to impart a golden or "creamy" hue to a glass of milk. The riboflavin in the whey portion of milk has a greenish color, which sometimes can be discerned in skimmed milk or whey products.[21] 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.[80]
Processing

In most Western countries, centralized dairy facilities process milk and products obtained from milk, such as cream, butter, and cheese. In the U.S., these dairies usually are local companies, while in the Southern Hemisphere facilities may be run by large multi-national corporations such as Fonterra.
Pasteurization

Pasteurization is used to kill harmful pathogenic bacteria by heating the milk for a short time and then immediately cooling it. Types of pasteurized milk include full cream, reduced fat, skim milk, calcium enriched, flavored, and UHT.[82] The standard high temperature short time (HTST) process of 72°C for 15 seconds completely kills pathogenic bacteria in milk,[83] rendering it safe to drink for up to three weeks if continually refrigerated.[84] Dairies print best before dates on each container, after which stores remove any unsold milk from their shelves.
A side effect of the heating of pasteurization is that some vitamin and mineral content is lost. Soluble calcium and phosphorus decrease by 5%, thiamin and vitamin B12 by 10%, and vitamin C by 20%.[85] Because losses are small in comparison to the large amount of the two B-vitamins present, milk continues to provide significant amounts of thiamin and vitamin B12. The loss of vitamin C is not nutritionally significant, as milk is not an important dietary source of vitamin C.
Filtration
Microfiltration 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 skimmed milk and is pasteurized in the usual way, but the skimmed milk is forced through ceramic microfilters that trap 99.9% of microorganisms in the milk[86] (as compared to 99.999% killing of microorganisms in standard HTST pasteurization).[87] The skimmed milk then is recombined with the pasteurized cream to reconstitute the original milk composition.
Ultrafiltration uses finer filters than microfiltration, which allow lactose and water to pass through while retaining fats, calcium and protein.[88] As with microfiltration, the fat may be removed before filtration and added back in afterwards.[89] Ultrafiltered milk is used is cheesemaking, since it has reduced volume for a given protein content, and is sold directly to consumers as a higher protein, lower sugar content, and creamier alternative to regular milk.[90]
Creaming and homogenization

Upon standing for 12 to 24 hours, fresh milk has a tendency to separate into a high-fat cream 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 cream separators. 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.[21] 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.[21]
Milk often is homogenized, 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 and cavitation.[91] A greater number of smaller particles possess more total surface area 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 enzymes present in milk, which could break down the fats and produce rancid 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.[21] 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.[92]
The homogenization process increases the shelf life of milk because it decreases the radius of fat globules and other particles (per Stokes's law) thus delaying the rate of agglomeration.
UHT
Ultra Heat Treatment (UHT), is a type of milk processing where all bacteria are destroyed with high heat to extend its shelf life for up to 6 months, as long as the package is not opened. Milk is firstly homogenized and then is heated to 138 degrees Celsius for 1–3 seconds. The milk is immediately cooled down and packed into a sterile container. As a result of this treatment, all the pathogenic bacteria within the milk are destroyed, unlike when the milk is just pasteurised. The milk will now keep for up for 6 months if unopened. UHT milk does not need to be refrigerated until the package is opened, which makes it easier to ship and store. But in this process there is a loss of vitamin B1 and vitamin C and there is also a slight change in the taste of the milk.[93]
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 globules, and the strength of the curd are among those that may vary.[23] For example:
Human milk contains, on average, 1.1% protein, 4.2% fat, 7.0% lactose (a sugar), and supplies 72 kcal of energy per 100 grams.
Cow's milk contains, on average, 3.4% protein, 3.6% fat, and 4.6% lactose, 0.7% minerals[94] and supplies 66kcal of energy per 100grams. See also Nutritional value further on
Donkey and horse milk have the lowest fat content, while the milk of seals and whales may contain more than 50% fat.[95]

Cow's milk
These compositions vary by breed, animal, and point in the lactation period.

The protein range for these four breeds is 3.3% to 3.9%, while the lactose range is 4.7% to 4.9%.[21]
Milk fat percentages may be manipulated by dairy farmers' stock diet formulation strategies. Mastitis infection can cause fat levels to decline.[96]
Nutritional value

Processed cow's milk was formulated to contain differing amounts of fat during the 1950s. One cup (250mL) of 2%-fat cow's milk contains 285mg of calcium, which represents 22% to 29% of the daily recommended intake (DRI) of calcium for an adult. Depending on its age, milk contains 8grams of protein, and a number of other nutrients (either naturally or through fortification) including:
Biotin
Iodine
Magnesium
Pantothenic acid
Potassium
Riboflavin
Selenium
Thiamine
Vitamin A
Vitamin B12
Vitamins D
Vitamin K
The amount of calcium from milk that is absorbed by the human body is disputed.[102] Calcium from dairy products has a greater bioavailability than calcium from certain vegetables, such as spinach, that contain high levels of calcium-chelating agents,[103] but a similar or lesser bioavailability than calcium from low-oxalate vegetables such as kale, broccoli, or other vegetables in the genus Brassica.[104][105]
Milk as a calcium source has been questioned in media, but scientific research is lacking to support the hypothesis of acidosis induced by milk. The hypothesis in question being that acidosis would lead to leeching of calcium storages in bones to neutralize pH levels (also known as acid-ash hypothesis).
Research has found no link between metabolic acidosis and consumption of milk.[106][107][108]
Recommended consumption
The U.S. federal government document Dietary Guidelines for Americans, 2010[109] recommends consumption of three glasses of fat-free or low-fat milk for adults and children 9 and older (less for younger children) per day. This recommendation is disputed by some health researchers who call for more study of the issue, given that there are other sources for calcium and vitamin D. The researchers also claim that the recommendations have been unduly influenced by the American dairy industry,[110] and that whole milk may be better for health due to its increased ability to satiate hunger.
Medical research
A 2008 review found evidence suggesting that consumption of milk is effective at promoting muscle growth.[111] Some studies have suggested that conjugated linoleic acid, which can be found in dairy products, is an effective supplement for reducing body fat.[112] With regards to the claim of milk promoting stronger bones, there has been no association between milk consumption or excess calcium intake[113] and a reduced risk of bone fractures.
In 2011, The Journal of Bone and Mineral Research published a meta-analysis examining whether milk consumption might protect against hip fracture in middle-aged and older adults. Studies could find no association between drinking milk and lower rates of fractures.[114] In 2014, JAMA Pediatrics published a report after monitoring almost 100,000 men and women for more than two decades. Subjects were asked to report on how much milk they had consumed as teenagers, and were followed to see if there is any association with a reduced chance of hip fractures later in life, it found there was not any.[115][116] A study published in The BMJ that followed more than 45,000 men and 61,000 women in Sweden age 39 and older had similar results. Milk consumption in adults was associated with no protection for men, and an increased risk of fractures in women. The risk of any bone fracture increased 16% in women who drank three or more glasses daily, and the risk of a broken hip increased 60%. It was also associated with an increased risk of death in both sexes.[116]
Milk and dairy products have the potential for causing serious infection in newborn infants. Unpasteurized milk and cheeses can promote the growth of Listeria bacteria. Listeria monocytogenes can also cause serious infection in an infant and pregnant woman and can be transmitted to her infant in utero or after birth. The infection has the potential of seriously harming or even causing the death of a preterm infant, an infant of low or very low birth weight, or an infant with an immune system defect or a congenital defect of the immune system. The presence of this pathogen can sometimes be determined by the symptoms that appear as a gastrointestinal illness in the mother. The mother can also acquire infection from ingesting food that contains other animal products such as, hot dogs, delicatessen meats, and cheese.[117]
Lactose intolerance

Lactose, the disaccharide sugar component of all milk, must be cleaved in the small intestine by the enzyme lactase, in order for its constituents, galactose and glucose, to be absorbed. Lactose intolerance is a condition in which people have symptoms due to not enough of the enzyme lactase in the small intestines.[118] Those affected vary in the amount of lactose they can tolerate before symptoms develop. These may include abdominal pain, bloating, diarrhea, gas, and nausea. Severity depends on the amount a person eats or drinks.[119] Those affected are usually able to drink at least one cup of milk without developing significant symptoms, with greater amounts tolerated if drunk with a meal or throughout the day.[119][120]
Lactose intolerance does not cause damage to the gastrointestinal tract.[121] There are four types: primary, secondary, developmental, and congenital. Primary lactose intolerance is when the amount of lactase decline as people age. Secondary lactose intolerance is due to injury to the small intestine such as from infection, celiac disease, inflammatory bowel disease, or other diseases.[119][122] Developmental lactose intolerance may occur in premature babies and usually improves over a short period of time. Congenital lactose intolerance is an extremely rare genetic disorder in which little or no lactase is made from birth.[119] When lactose intolerance is due to secondary lactase deficiency, treatment of the underlying disease allows lactase activity to return to normal levels.[123] Lactose intolerance is different from a milk allergy.[119]
The number of people with lactose intolerance is unknown.[124] Some human populations have developed lactase persistence, in which lactase production continues into adulthood probably as a response to the benefits of being able to digest milk from farm animals.[118] The percentage of the population that has a decrease in lactase as they age is less than 10% in Northern Europe and as high as 95% in parts of Asia and Africa.[118]
Possible harms

Some studies suggest that milk consumption may increase the risk of suffering from certain health problems. Cow's milk allergy (CMA) is an immunologically mediated adverse reaction, rarely fatal, to one or more cow's milk proteins.[125] Milk from any mammal contains amino acids and microRNA which influence the drinker's metabolism and growth;[126] this "programming" is beneficial for milk's natural consumers, namely infants of the same species as the milk producer, but post-infancy and trans-species milk consumption affects the mTORC1 metabolic pathway and may promote diseases of civilization such as obesity and diabetes.[126][127]
Milk contains exogenous opioid peptides called exorphins which include opioid food peptides like Gluten exorphin and opioid food peptides. Exorphins mimic the actions of endorphines because they bind to the same opioid receptors in the brain. The exorphin in milk is called casein, a substance that breaks down in the human stomach to produce the opioid peptide casomorphin. In the early 1990s it was hypothesized that casomorphin can cause or aggravate autism spectrum disorders,[128][129] and casein-free diets are widely promoted. Studies supporting these claims have had significant flaws, and the data are inadequate to guide autism treatment recommendations.[129][130]
The most recent assessment by the World Cancer Research Fund and the American Institute for Cancer Research found that most individual epidemiological studies showed increased risk of prostate cancer with increased intake of milk or dairy products.[131] "Meta-analysis of cohort data produced evidence of a clear dose-response relationship between advanced/aggressive cancer risk with milk intake, and between all prostate cancer risk and milk and dairy products." Possible mechanisms proposed included inhibition of the conversion of vitamin D to its active metabolite, 1,25- dihydroxy vitamin D3 by calcium (which some evidence suggests increases cell proliferation in the prostate), and elevation of levels of insulin-like growth factor-1 (IGF-1).[131] Several sources suggest a correlation between high calcium intake from milk, in particular, and prostate cancer,[132][133][134] consistent with a calcium/vitamin D based mechanism. Overall, the WCRF/AICR panel concluded that "The evidence is inconsistent from both cohort and case-control studies. There is limited evidence suggesting that milk and dairy products are a cause of prostate cancer."[131]
Flavored milk in U.S. schools
Milk must be offered at every meal if a United States school district wishes to get reimbursement from the federal government.[135] A quarter of the largest school districts in the U.S. offer rice or soy milk and almost 17% of all U.S. school districts offer lactose-free milk. Of the milk served in U.S. school cafeterias, 71% is flavored, causing some school districts to propose a ban because flavored milk has added sugars. (Though some flavored milk products use artificial sweeteners instead.) The Boulder, Colorado, school district banned flavored milk in 2009 and instead installed a dispenser that keeps the milk colder.[135]
Bovine growth hormone supplementation
Since November 1993, recombinant bovine somatotropin (rbST), also called rBGH, has been sold to dairy farmers with FDA approval. Cows produce bovine growth hormone naturally, but some producers administer an additional recombinant version of BGH which is produced through genetically engineered E. coli to increase milk production. Bovine growth hormone also stimulates liver production of insulin-like growth factor 1 (IGF1). The U.S. Food and Drug Administration,[136] the National Institutes of Health[137] and the World Health Organization[138] have reported that both of these compounds are safe for human consumption at the amounts present.
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.[139] 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.[140] 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 cells in milk vary naturally.[141][142]
rBGH is also banned in the European Union.[143]
Criticism

Vegans and some other vegetarians do not consume milk for reasons mostly related to animal rights and environmental concerns. They may object to features of dairy farming including the necessity of keeping dairy cows pregnant, the killing of almost all the male offspring of dairy cows (either by disposal soon after birth, for veal production, or for beef), the routine separation of mother and calf soon after birth, other perceived inhumane treatment of dairy cattle, and culling of cows after their productive lives.[144]
Some have criticized the American government's promotion of milk consumption. Their main concern is the financial interest that the American government has taken in the dairy industry, promoting milk as the best source of calcium. All United States schools that are a part of the federally funded National School Lunch Act are required by the federal government to provide milk for all students. The Office of Dietary Supplements recommends that healthy adults between ages 19 and 50 get about 1,000mg of calcium per day.[145]
Milk production is also resource intensive. On a global weighted average, for the production of a given volume of milk, a thousand times as much water has to be used.[146]
Varieties and brands

Milk products are sold in a number of varieties based on types/degrees of:
additives (e.g. vitamins, flavorings)
age (e.g. cheddar, old cheddar)
coagulation (e.g. cottage cheese)
farming method (e.g. organic, grass-fed)
fat content (e.g. half and half, 3% fat milk, 2% milk, 1% milk, skim milk)
fermentation (e.g. buttermilk)
flavoring (e.g. chocolate and strawberry)
homogenization (e.g. cream top)
packaging (e.g. bottle, carton, bag)
pasteurization (e.g. raw milk, pasteurized milk)
reduction or elimination of lactose
species (e.g. cow, goat, sheep)
sweetening (e.g., chocolate and strawberry milk)
water content (e.g. dry milk powder, condensed milk, ultrafiltered milk)
Milk preserved by the UHT process does not need to be refrigerated before opening and has a much longer shelf life (six months) than milk in ordinary packaging. It is typically sold unrefrigerated in the UK, 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, where approximately 17% of the Finnish-speaking population has hypolactasia,[147] 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 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 separation method to remove lactose. Valio also markets these products in Sweden, Estonia, Belgium,[148] and the United States, where the company says ultrafiltration is used.[149]
In the UK, where an estimated 4.7% of the population are affected by lactose intolerance,[150] Lactofree produces milk, cheese, and yogurt products that contain only 0.03% lactose.
To aid digestion in those with lactose intolerance, milk with added bacterial cultures such as Lactobacillus acidophilus ("acidophilus milk") and bifidobacteria ("a/B milk") is available in some areas.[151] Another milk with Lactococcus lactis bacteria cultures ("cultured buttermilk") often is used in cooking to replace the traditional use of naturally soured milk, which has become rare due to the ubiquity of pasteurization, which also kills the naturally occurring Lactococcus bacteria.[152]
Lactose-free and lactose-reduced milk can also be produced via ultra filtration, which removes smaller molecules such as lactose and water while leaving calcium and proteins behind. Milk produced via these methods has a lower sugar content than regular milk.[88]
Additives and flavoring
In areas where the cattle (and often the people) live indoors, commercially sold milk commonly has vitamin D added to it to make up for lack of exposure to UVB 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 this results in reduced fat milks having a higher vitamin A content than whole milk.[153]
Milk often has flavoring added to it for better taste or as a means of improving sales. Chocolate milk has been sold for many years and has been followed more recently by strawberry milk 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.[154]
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 are no longer available in most countries.
Australia and New Zealand
In Australia and New Zealand, prior to metrication, milk was generally distributed in 1 pint (568mL) glass bottles. In Australia and 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 600mL 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.[155]
Milk is now available in a variety of sizes in paperboard milk cartons (250mL, 375mL, 600mL, 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 flavored milks – for example, as mentioned above, Farmers Union Iced Coffee outsells Coca-Cola in South Australia.
India
In rural India, milk is home delivered, daily, by local milkmen carrying bulk quantities in a metal container, usually on a bicycle. In other parts of metropolitan India, milk is usually bought or delivered in plastic bags or cartons via shops or supermarkets.
The current milk chain flow in India is from milk producer to milk collection agent. Then it is transported to a milk chilling center and bulk transported to the processing plant, then to the sales agent and finally to the consumer.
A 2011 survey by the Food Safety and Standards Authority of India found that nearly 70% of samples had not conformed to the standards set for milk. The study found that due to lack of hygiene and sanitation in milk handling and packaging, detergents (used during cleaning operations) were not washed properly and found their way into the milk. About 8% of samples in the survey were found to have detergents, which are hazardous to health.[156]
Pakistan
In Pakistan, 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. The classic milkman, who travels his local milk round (route) using a milk float (often battery powered) during the early hours and delivers milk in 1 pint glass bottles with aluminium foil tops directly to households, has almost disappeared. Two of the main reasons for the decline of UK home deliveries by milkmen are household refrigerators (which lessen the need for daily milk deliveries) and private car usage (which has increased supermarket shopping). Another factor is that it is cheaper to purchase milk from a supermarket than from home delivery. 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.[157] By 2010, the estimated number of milkmen had dropped to 6,000.[158] 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 UK households (6.7 billion liters in 2008/2009).[159]
Almost 95% of all milk in the UK 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 UK 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 "half pint" (237mL, 5⁄12imppt) 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 (UV) light from fluorescent lighting can alter the flavor of milk, so many companies that once distributed milk in transparent or highly translucent containers are now using thicker materials that block the UV light.
Milk comes in a variety of containers with local variants:
Argentina
Commonly sold in 1 liter bags and cardboard boxes. The bag is then placed in a plastic jug and the corner cut off before the milk is poured.
Australia and New Zealand
Distributed in a variety of sizes, most commonly in aseptic cartons for up to 1.5 liters, and plastic screw-top bottles beyond that with the following volumes; 1.1L, 2L, and 3L. 1 liter milk bags 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.[155]
Brazil
Used to be sold in cooled 1 liter bags, just like in South Africa. 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
1.33 liter plastic bags (sold as 4 liters in 3 bags) are widely available in some areas (especially the Maritimes, Ontario and Quebec), although the 4 liter plastic jug has supplanted them in western Canada. Other common packaging sizes are 2 liter, 1 liter, 500 mL, and 250 mL cartons, as well as 4 liter, 1 liter, 250mL aseptic cartons and 500mL plastic jugs.
Chile
Distributed most commonly in aseptic 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
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.
Colombia
Sells milk in 1 liter plastic bags.
Croatia, Bosnia and Herzegovina, Serbia, Montenegro
UHT milk (trajno mlijeko/trajno mleko/трајно млеко) is sold in 500mL and 1L (sometimes also 200 mL) aseptic cartons. Non-UHT pasteurized milk (svježe mlijeko/sveže mleko/свеже млеко) is most commonly sold in 1L and 1.5L PET bottles, though in Serbia one can still find milk in plastic bags.
Estonia
Commonly sold in 1 L bags or 0.33 L, 0.5 L, 1 L or 1.5 L cartons.
Parts of Europe
Sizes of 500 mL, 1 liter (the most common), 1.5 liters, 2 liters and 3 liters are commonplace.
Finland
Commonly sold in 1 L or 1.5 L cartons, in some places also in 2dl and 5dl cartons.
Germany
Commonly sold in 1-liter cartons. Sale in 1-liter plastic bags (common in the 1980s) now rare.
Hong Kong
Milk is sold in glass bottles (220 mL), cartons (236 mL and 1L), plastic jugs (2 liters) and aseptic cartons (250mL).
India
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
Usually sold in 1 liter cartons, but smaller, snack-sized cartons are available.
Israel

Non-UHT milk is most commonly sold in 1 liter waxed cardboard boxes and 1 liter plastic bags. It may also be found in 1.5L and 2L waxed cardboard boxes, 2L plastic jugs and 1 L plastic bottles. UHT milk is available in 1 liter (and less commonly also in 0.5L) carton "bricks".
Japan
Commonly sold in 1 liter waxed paperboard cartons. In most city centers there is also home delivery of milk in glass jugs. As seen in China, sweetened and flavored milk drinks are commonly seen in vending machines.
Kenya
Milk in Kenya is mostly sold in plastic-coated aseptic paper cartons supplied in 300 mL, 500 mL or 1 liter volumes. In rural areas, milk is stored in plastic bottles or gourds.[160][161] The standard unit of measuring milk quantity in Kenya is a liter.
Pakistan
Milk is supplied in 500 mL plastic bags and carried in jugs from rural to cities for selling
Philippines
Milk is supplied in 1000 mL plastic bottles and delivered from factories to cities for selling.
Poland
UHT milk is mostly sold in aseptic cartons (500mL, 1L, 2L), and non-UHT in 1L plastic bags or plastic bottles. Milk, UHT is commonly boiled, despite being pasteurized.
South Africa
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.
South Korea
Sold in cartons (180mL, 200mL, 500mL 900mL, 1L, 1.8L, 2.3L), plastic jugs (1L and 1.8L), aseptic cartons (180 mL and 200 mL) and plastic bags (1 L).
Sweden

Commonly sold in 0.3L, 1L or 1.5L cartons and sometimes as plastic or glass milk bottles.
Turkey
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
Most stores stock imperial sizes: 1 pint (568mL), 2 pints (1.136L), 4 pints (2.273L), 6 pints (3.408L) 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. 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
Commonly sold in gallon (3.78L), half-gallon (1.89L) and quart (0.94L) containers of natural-colored HDPE resin, or, for sizes less than one gallon, cartons of waxed paperboard. Bottles made of opaque PET are also becoming commonplace for smaller, particularly metric, sizes such as one liter. The U.S. 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 chains in the United States (such as Kwik Trip in the Midwest) sell milk in half-gallon bags, while another rectangular cube gallon container design used for easy stacking in shipping and displaying is used by warehouse clubs such as Costco and Sam's Club, along with some Wal-Mart stores.[162]
Uruguay
Pasteurized milk is commonly sold in 1 liter bags and ultra-pasteurized milk is sold in cardboard boxes called Tetra Briks. Non-pasteurized milk is forbidden. Until the 1960s no treatment was applied; milk was sold in bottles. As of 2017, plastic jugs used for pouring the bags, or "sachets", are in common use.
Practically everywhere, condensed milk and evaporated milk are distributed in metal cans, 250 and 125mL paper containers and 100 and 200mL squeeze tubes, and powdered milk (skim and whole) is distributed in boxes or bags.
Spoilage and fermented milk products

When raw milk is left standing for a while, it turns "sour". This is the result of fermentation, where lactic acid bacteria ferment the lactose in the milk into lactic acid. 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 sp., Leuconostoc sp., etc.) to produce a variety of fermented milk products. 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, yogurt, cheese, buttermilk, viili, kefir, and kumis. See Dairy product for more information.
Pasteurization of cow's milk initially destroys any potential pathogens and increases the shelf life,[163][164] 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-producing bacteria, under suitable conditions, ferments the lactose present to lactic acid. The increasing acidity 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 and stored between 1 and 4°C (34 and 39°F) in bulk tanks. Most milk is pasteurized by heating briefly and then refrigerated to allow transport from factory farms 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, made by removing most of the water, can be stored in cans for many years, unrefrigerated, as can evaporated milk. The most durable form of milk is powdered milk, which is produced from milk by removing almost all water. The moisture content is usually less than 5% in both drum- and spray-dried powdered milk.
Freezing of milk can cause fat globule aggregation upon thawing, resulting in milky layers and butterfat lumps. These can be dispersed again by warming and stirring the milk.[165] It can change the taste by destruction of milk-fat globule membranes, releasing oxidized flavors.[165]
Use in other food products

Milk is used to make yogurt, cheese, ice milk, pudding, hot chocolate and french toast. Milk is often added to dry breakfast cereal, porridge and granola. Milk is often served in coffee and tea. Steamed milk is used to prepare espresso-based drinks such as cafe latte.
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", the expression "there's no use crying over spilt milk" (which means don't "be unhappy about what cannot be undone"), "don't milk the ram" (this means "to do or attempt something futile") and "Why buy a cow when you can get milk for free?" (which means "why pay for something that you can get for free otherwise").[166]
In Greek mythology, the Milky Way was formed after the trickster god Hermes suckled the infant Heracles at the breast of Hera, the queen of the gods, while she was asleep.[167][168] When Hera awoke, she tore Heracles away from her breast and splattered her breast milk across the heavens.[167][168] In another version of the story, Athena, the patron goddess of heroes, tricked Hera into suckling Heracles voluntarily,[167][168] but he bit her nipple so hard that she flung him away, spraying milk everywhere.[167][168]
In many African and Asian countries, butter is traditionally made from fermented milk rather than cream. It can take several hours of churning to produce workable butter grains from fermented milk.[169]
Holy books have also mentioned milk. The Bible contains references to the "Land of Milk and Honey." In the Qur'an, 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 Ramadan fast is traditionally broken with a glass of milk and dates.
Abhisheka is conducted by Hindu and Jain priests, by pouring libations on the image of a deity being worshipped, amidst the chanting of mantras. Usually offerings such as milk, yogurt, ghee, honey may be poured among other offerings depending on the type of abhishekam being performed.
A milksop is an "effeminate spiritless man," an expression which is attested to in the late 14th century.[12] Milk toast is a dish consisting of milk and toast. Its soft blandness served as inspiration for the name of the timid and ineffectual comic strip character Caspar Milquetoast, drawn by H. T. Webster from 1924 to 1952.[170] Thus, the term "milquetoast" entered the language as the label for a timid, shrinking, apologetic person. Milk toast also appeared in Disney's Follow Me Boys as an undesirable breakfast for the aging main character Lem Siddons.
To "milk" someone, in the vernacular of many English-speaking countries, is to take advantage of the person, by analogy to the way a farmer "milks" a cow and takes its milk. The word "milk" has had many slang meanings over time. In the 19th century, milk was used to describe a cheap and very poisonous alcoholic drink made from methylated spirits (methanol) 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.[171]
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 and fertilizer,[172][173][174] however, its effectiveness is debated. 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.[175][176]
See also

A2 milk
Babcock test (determines the butterfat content of milk)
Blocked milk duct
Fermented milk products
Health mark
Human breast milk
Lactation
List of dairy products
Milk line
Milk paint
Milk substitute
Milky Way
Operation Flood
Raw milk

Further reading
Dupuis, E. Melanie. Nature's Perfect Food (2002)
Kardashian, Kirk. Milk Money: Cash, Cows, and the Death of the American Dairy Farm (2012)

Smith-Howard, Kendra. Pure and Modern Milk: An Environmental History Since 1900. Oxford, England: Oxford University Press; 2013.
Valenze, Deborah. Milk: A Local and Global History (Yale University Press, 2011) 368 pp.
Wiley, Andrea. Re-imagining Milk: Cultural and Biological Perspectives (Routledge 2010) (Series for Creative Teaching and Learning in Anthropology)
United States. Office of Dietary Supplements. Dietary Supplement Fact Sheet: Calcium. 2013. Web. <>.

 at Curlie


A baseball bat is a smooth wooden or metal club used in the sport of baseball to hit the ball after it is thrown by the pitcher. By regulation it may be no more than 2.75 inches (7.0cm) in diameter at the thickest part and no more than 42 inches (1.067m) in length. Although historically bats approaching 3 pounds (1.4kg) were swung,[1] today bats of 33 ounces (0.94kg) are common, topping out at 34 ounces (0.96kg) to 36 ounces (1.0kg).[1]
Terminology
A baseball bat is divided into several regions. The "barrel" is the thick part of the bat, where it is meant to hit the ball. The part of the barrel best for hitting the ball, according to construction and swinging style, is often called the "sweet spot." The end of the barrel is called the "top," "end," or "cap" of the bat. Opposite the cap, the barrel narrows until it meets the "handle," which is  comparatively thin, so that batters can comfortably grip the bat in their hands. Sometimes, especially on metal bats, the handle is wrapped with a rubber or tape "grip". Finally, below the handle is the "knob" of the bat, a wider piece that keeps the bat from slipping from a batter's hands.
"Lumber" is an often-used slang term for a bat, especially when wielded by a particularly able batter.
The "bat drop" of a bat is its weight, in ounces, minus its length, in inches. For example, a 30-ounce, 33-inch-long bat has a bat drop of minus 3 (30 − 33 = −3). Larger bat drops help to increase swing speed; smaller drops create more power.
History
The bat's form has become more refined over time. In the mid-19th century, baseball batters were known to shape or whittle their own bats by hand, which resulted in a wide range of shapes, sizes, and weights. For example, there were flat bats, round bats, short bats, and fat bats. Earlier bats were known to be much heavier and larger than today's regulated ones. During the 19th century, many shapes were experimented with, as well as handle designs. Today, bats are much more uniform in design.
Innovations

On June 17, 1890, Emile Kinst patented the ball-bat, or banana bat. The bat is shaped with a curve, hence the name banana bat. The creator of the bat, Kinst wrote: "The object of my invention is to provide a ball-bat which shall produce a rotary or spinning motion of the ball in its flight to a higher degree than is possible with any present known form of ball-bat, and thus to make it more difficult to catch the ball, or if caught, to hold it, and thus further to modify the conditions of the game".
The mushroom bat, made in 1906 by Spalding. With baseball bats being larger in the 1900s the Spalding company designed a larger bat with a mushroom-shaped knob on the handle. This enabled the batter to get a better distribution of weight over the entire length of the bat.
The Wright & Ditsons Lajoie baseball bat. This bat had a normal size barrel but had two knobs on the handle. The lowest knob was at the bottom of the handle and the other knob was roughly two inches above the lowest knob. This was designed to have better spacing between the hands due to the knob being in the middle of the grip. This also gave batters an advantage when they choked up on the bat, because the second knob provided a better grip.
In 1990, Bruce Leinert came up with the idea of putting an axe handle on a baseball bat. He filed a patent application for the 'Axe Bat' in 2007 and the bat started being used in the college and pro ranks over the following years. In 2012, the Marietta College Pioneers baseball team won the NCAA Division III World Series using axe handled bats.[2] Several Major League Baseball players have adopted the bat handle including Mookie Betts, Dustin Pedroia, George Springer, Kurt Suzuki and Dansby Swanson.[3][4]
Materials and manufacture
Baseball bats are made of either wood, or a metal alloy (typically aluminum). Most wooden bats are made from ash; other woods include maple, hickory, and bamboo. Hickory has fallen into disfavor over its greater weight, which slows down bat speed, while maple bats gained popularity[5] following the introduction of the first major league sanctioned model in 1997. The first player to use one was Joe Carter of the Toronto Blue Jays.[6] Barry Bonds used maple bats the seasons he broke baseball's single-season home run record in 2001, and the career home run record in 2007.[6] In 2010, the increased tendency of maple bats to shatter caused Major League Baseball to examine their use, banning some models in minor league play.[7][8]
Manufacturers position each bat's label over the mechanically weaker side of the wood.[9]
To reduce chance of fracture,[9] and maybe deliver more energy to the ball,[10] a bat is intended to be held so the label faces sky or ground when it strikes the ball during a horizontal swing.[9] In this orientation, the bat is considered stiffer and less likely to break.[11]
Different types of wood will fracture differently.[12] For bats made of ash, labels will generally be where the grain spacing is widest. For maple bats they will usually be positioned where grain is tightest.
Maple bats in particular were once known (circa 2008) to potentially shatter in a way that resulted in many sharp edges, sometimes creating more dangerous projectiles when it broke.[9][13] Maple bat manufacture evolved significantly, in cooperation with Major League Baseball,[11] paying special attention to grain slope, and including an ink spot test to confirm safest wood grain orientation.[11]
Based on consistent anecdotal reports of sales at sporting goods stores, Maple appears to be displacing Ash as most popular new baseball bat material in the United States. Next and rising in popularity is Bamboo, which has more isotropic fine grain, great strength, and less weight for a bat of any given size.
Within league standards there is ample latitude for individual variation, many batters settling on their own bat profile, or one used by a successful batter. Formerly, bats were hand-turned from a template with precise calibration points; today they are machine-turned to a fixed metal template. Historically significant templates may be kept in a bat manufacturers' vault; for example, Babe Ruth's template, which became popular among major-league players, is R43 in the Louisville Slugger archives.  Ruth favored a thinner handle than was the norm in the 1920s, and his success caused most to follow.[14]
Once the basic bat has been turned, it has the manufacturer's name, the serial number, and often the signature of the player endorsing it branded into it opposite the wood's best side. Honus Wagner was the first player to endorse and sign a bat. Next, most bats are given a rounded head, but some 30% of players prefer a "cup-balanced" head, in which a cup-shaped recess is made in the head; this lightens the bat and moves its center of gravity toward the handle. Finally, the bat is stained in one of several standard colors, including natural, red, black, and two-tone blue and white.
Environmental threat to ash wood
The emerald ash borer, an exotic beetle imported accidentally from Asia, has killed more than 50 million trees and now threatens groves in New York's Adirondack Mountains that are used to make baseball bats.[15] Global temperature rise likely allows the beetle to survive in what was once too cold of a climate.[5]
Regulations
In the American major leagues, Rule 1.10(a) states:[16]
The bat shall be a smooth, round stick not more than 2.61 inches in diameter at the thickest part and not more than 42 inches in length. The bat shall be one piece of solid wood.
Bats are not allowed to be hollowed or corked—that is, filled with an alien substance such as cork which reduces the weight. This corking is thought to increase bat speed without greatly reducing hitting power, though this idea was challenged as unlikely on the Discovery Channel series MythBusters.[17]
Both wooden and metal alloy (generally aluminum) bats are generally permitted in amateur baseball. Metal alloy bats are generally regarded as being capable of hitting a ball faster and farther with the same power. However, increasing numbers of "wooden bat leagues" have emerged in recent years, reflecting a trend back to wood over safety concerns and, in the case of collegiate summer baseball wood-bat leagues, to better prepare players for the professional leagues that require wood bats. Metal alloy bats can send a ball towards an unprotected pitcher's head up to 60ft 6in (18.44m) away at a velocity far too high for the pitcher to get out of the way in time. Some amateur baseball organizations enforce bat manufacturing and testing standards which attempt to limit maximum ball speed for wood and non-wood bats.[18][19][20]
In high school baseball in the United States:
The bat is not permitted to be more than 25⁄8 inches (67mm) in diameter.
Its "drop" (inches of length minus ounces of weight) must be no more than 3: for example, a 34‑inch (863.6‑mm) bat must weigh at least 31 ounces (880g).[21]
The bat may consist of any safe solid uniform material; the National Federation of State High School Associations rules state only "wood or non-wood" material.
To be legally used in a game, an aluminum bat has to be a BBCOR (Batted Ball Coefficient of Restitution) bat because it has been determined that a pitcher loses the ability to protect himself when this ratio is exceeded.
In some 12-year-old-and-under youth leagues (such as Little League baseball), the bat may not be more than 21⁄4 inches (57mm) in diameter.[22]  However, in many other leagues (like PONY League Baseball, and Cal Ripken League Baseball), the bat may not be more than 23⁄4 inches (70mm) in diameter.[23]
There are limitations to how much and where a baseball player may apply pine tar to a baseball bat. According to Rule 1.10(c) of the Major League Baseball Rulebook, it is not allowed more than 18inches up from the bottom handle. An infamous example of the rule in execution is the Pine Tar Incident on July 24, 1983. Rules 1.10 and 6.06 were later changed to reflect the intent of Major League Baseball, as exemplified by the league president's ruling. Rule 1.10 now only requires that the bat be removed from the game if discovered after being used in a game; it no longer necessitates any change to the results of any play which may have taken place. Rule 6.06 refers only to bats that are "altered or tampered with in such a way to improve the distance factor or cause an unusual reaction on the baseball. This includes, bats that are filled, flat-surfaced, nailed, hollowed, grooved or covered with a substance such as paraffin, wax, etc."  It no longer makes any mention of an "illegally batted ball". In 2001, MLB approved the use of Gorilla Gold Grip Enhancer in major and minor league games as an alternative to pine tar.[24][25]
Care and maintenance

Players can be very particular about their bats. Ted Williams cleaned his bats with alcohol every night and periodically took them to the post office to weigh them. "Bats pick up condensation and dirt lying around on the ground," he wrote, "They can gain an ounce or more in a surprisingly short time." Ichiro Suzuki also takes great care that his bats do not accumulate moisture and thus gain weight: he stores his bats in humidors, one in the club house and another, a portable one, for the road. Rod Carew fought moisture by storing his bats in a box full of sawdust in the warmest part of his house. "The sawdust acts as a buffer between the bats and the environment," he explained, "absorbing any moisture before it can seep into the wood."[26]
Many players "bone" their bats, meaning that before games, they rub their bats repeatedly with a hard object, believing this closes the pores on the wood and hardens the bat. Animal bones are a popular boning material, but rolling pins, soda bottles and the edge of a porcelain sink have also been used. Pete Rose had his own way of hardening his bats: he soaked them in a tub of motor oil in his basement then hung them up to dry.[26]
Fungo bat
A fungo bat is a specially designed bat used by baseball and softball coaches for practice. The etymology of the word fungo (/ˈfʌŋɡoʊ/) is uncertain, but the Oxford English Dictionary suggests it is derived from the Scots fung: to pitch, toss, or fling.[27] A fungo is longer and lighter than a regulation bat, with a smaller diameter. The bat is designed to hit balls tossed up in the air by the batter, not pitched balls.[28] Typical fungo bats are 35 to 37 inches (89 to 94cm) long and weigh 17 to 22 ounces (480 to 620g). Coaches hit many balls during fielding practice, and the weight and length allow the coach to hit balls repeatedly with high accuracy. The small diameter also allows coaches to easily hit pop-ups to catchers and infielders along with ground balls due to better control of the barrel of the bat.
As a weapon
Baseball bats are often used as a club-like weapon.
See also
Composite baseball bat
Pink bat
List of baseball bat manufacturers
Cricket bat
Softball bat

—How baseball bats work, how bat performance is measured, differences between wood, metal, and composite bats
—Making a Baseball Bat

. Talk of the Nation. National Public Radio, July 4, 2008.


Chamber pressure (firearms) is the pressure exerted by a cartridge case's outside walls on the inside of a firearm's chamber when the cartridge is fired.  It is generally expressed in PSI (pounds per square inch) or copper units of pressure.
Overview
When the firing pin in a firearm strikes the primer, it ignites the powder inside the case, creating an explosion that generates a large amount of pressure, often exceeding 50,000 PSI.[1]  This pressure in turn pushes the bullet out of the case mouth and into the barrel.  During this explosion, the brass walls of the cartridge expand and seal against the inner walls of the chamber.  This expansion is what creates chamber pressure, or the amount of force applied to the inside of the chamber by the case.  For all commercially available cartridges, the Sporting Arms and Ammunition Manufacturer's Institute () publish the maximum safe chamber pressures.
Measuring Methods
There are 3 basic methods for measuring chamber pressure:[2]
Using a copper crusher
The Piezo method
Attaching a strain gauge to the barrel forward of the chamber
Copper Crusher Method
Through the mid-1960s, the most common way of measuring pressure was drilling a hole through the chamber of the barrel and inserting a copper slug that fit flush with the chamber walls.  When a cartridge is fired, it compresses the copper slug.  It is then removed, measured, and compared to the original dimensions.  Using the known properties of copper, the chamber pressure can then be calculated and expressed in copper units of pressure (CUP).[3]  While there are now more accurate methods of measuring chamber pressure, the copper crusher method is still used for verification purposes.[2]
The Piezo Method
Developed in the late 1960s the most common method of accurately measuring chamber pressure is the Piezo method.  It is similar to the copper crusher method where a hole is drilled into the chamber, but rather than a copper slug a quartz crystal transducer is inserted and attached to sensitive measuring equipment.[4]  This method generally yields more accurate readings than the copper crusher, and is more cost efficient due to the fact that the transducer can be reused.
Strain Gauge Method
The strain gauge method is the least accurate method of measuring chamber pressure using equipment, but has the advantage of being the least expensive and requires no permanent modifications to the firearm.[2]  A strain gauge is attached to the barrel just forward of the chamber.  Upon firing, the barrel stretches briefly, and this stretch is measured by the gauge.[5]  This method is generally reserved as a way of relatively comparing different cartridge loads as the strain gauge reading is not as accurate as a copper crusher or Piezo test.
Importance in Firearm Maintenance
The force that is not exerted on the chamber walls is used to push the bullet down the barrel.  Because the volume of the case is relatively small, the pressure closest to the chamber will be higher than at any other point in the barrel.  Compared to the temperature of the powder being burned, a relatively small amount of energy and heat is transferred from the powder in the barrel to the barrel walls.  Therefore, the entire process can be considered an adiabatic process, or no heat is lost during the rapid expansion of the gases.  Thus, the ideal gas law can be used to express the difference in pressure as the bullet travels along the barrel:[6]
P1V1=P2V2
or
P2=P1V1/V2
where:
P1 is the initial pressure
P2 is the pressure acting against the tail of the bullet at a given point
V1 is the internal case capacity, or volume of the loaded cartridge
V2 is the internal case capacity plus the volume of the barrel from the chamber to the bullet
Looking at this thermodynamic equation, it can be seen that the amount of pressure acting upon the bullet decreases at it travels down the barrel, or as the volume of the explosion increases.[6]  Likewise, it should be noted that the part of the barrel that is subject to the highest pressures is the throat, or the point closest to the chamber at which the bullet engages the rifling.  Because of this, the rifling at the throat will erode faster than the rest of the barrel.
Several measures can be taken to decrease the rate of throat erosion due to pressure, some of which can be achieved by handloading.
If a bullet is seated further out (i.e. closer to the rifling) it will increase the internal volume of the case.  By examining the ideal gas law, PV=nRT, it can be seen that by increasing the case volume, the pressure inside the case is reduced.  This in turn reduces the chamber pressure and the amount of force exerted upon the throat.
If the amount of powder is decreased, the explosion inside the case will be smaller and will result in less pressure.

What gas is produced when firing a firearm?


Tūheitia Paki, KStJ, GCCT, KCLJ (born 21 April 1955), crowned as Te Arikinui Kiingi Tūheitia, is the current Māori King in New Zealand. He is the eldest son of the previous Māori monarch, Dame Te Atairangikaahu, and was announced as her successor and crowned on 21 August 2006, the same day her tangihanga (funeral rites) took place.
Family
Tūheitia Paki is the son of Whatumoana Paki and Te Arikinui Dame Te Atairangikaahu, who married in 1952. He was educated at Rakaumanga School in Huntly, Southwell School in Hamilton and St Stephen's College in Bombay, south of Auckland. He has five sisters and one brother: Heeni Katipa (née Paki); Tomairangi Paki; Mihi ki te ao Paki; Kiki Solomon (née Paki); Manawa Clarkson (née Paki), and brother Maharaia Paki.[1]
He is married to Atawhai and has three children: Whatumoana, Korotangi, and Ngawai Hono I Te Po.[2] After Paki's ascent to the throne, Atawhai was appointed patroness of the Māori Women's Welfare League in 2007.[3]
Paki has diabetes and announced in 2013 that due to his health he was establishing Te Kaunihera a te Kiingi (King's Council) and deputising his elder son Whatumoana Te Aa Paki to act in his stead.[4][5] As the King's representative, Whatumoana was given the title Te Whirinaki a te Kīngi, the title held by Te Wherowhero Tāwhiao while he acted for King Mahuta in the early 1900s.[6][7]
Duties and background
Prior to becoming King, he was the Tainui Cultural Advisor to Te Wānanga o Aotearoa at Huntly.
He speaks publicly only once a year, at the annual celebrations in Ngaruawahia of his coronation.[8]
Since ascending to the throne his official duties have included attending the following events:
funeral of King Taufa'ahau Tupou IV of Tonga, September 2006
opening of Pūkawa Marae on the shore of Lake Taupo, Aotearoa, on 17–19 November 2006
opening of "Mauri Ora" an exhibition of Māori artefacts from Te Papa on exhibition at the Tokyo National Museum in Tokyo, Japan on 22 January 2007[9][10]
funeral of Malietoa Tanumafili II of Samoa, 19 May 2007
re-opening of the marae/war memorial hall in Ngaiotonga, Whangaruru 2007
opening of the Māori garden in Hamilton gardens, 2008[11]
unveiling of Te Kawerau a Maki's new pou for the Arataki Visitor Centre in the Waitakere Ranges in 2011[12]
haka and speech for the fleet of 110 waka to commemorate 160 years of kiingitanga in 2018[13]
Political issues
In March 2010, the King threatened to abdicate his title if tribal members "[did] not fall back into line."[14] He made the announcement after members of the tribe's parliament, Te Kauhanganui, questioned his use of tribal funds and his choice of company directors.[15] His office denied that he mentioned abdication.[16] At the heart of the allegations is the spending of Paki's office which has risen to an annual $1.2 million compared to $250,000 under his mother, with much of the spending going on travel.[17] The funds are provided by Tainui, which has assets worth more than $1 billion.[18]
In December 2010 he attempted to sack the Te Kauhanganui chairperson Tania Martin, Hiiona Marae's elected representative on Te Kauhanganui, in connection with a report which she tabled detailing financial issues.[19] However, the constitutional rules of Tainui's Parliament only allow for Te Kauhanganui itself to elect or remove its chairperson. As of January 2011, Mrs Martin remains the chairperson of Te Kauhanganui, having been reaffirmed by a vote.[20][21]
In March 2011, issues arose over travel expenses for Te Makau Ariki Atawhai and Te Ariki Tamaroa Whatumoana, Paki's consort and son.[22]
In June 2011, David Rankin of the Ngāpuhi iwi attacked both Paki and the Governments' use of the term "Māori King" to describe him, saying that not only had tribes such as Ngāpuhi never supported the kingitanga movement, but that Paki "[hadn't] even got the Reo" (or Māori language).[23]
Honours
On 27 November 2007, Paki was appointed an Officer of the Venerable Order of Saint John[24][25] and upgraded to a Knight in 2016.[26] He was appointed to Grand Cross of the Order of the Crown of Tonga during the coronation ceremonies of King George Tupou V of Tonga.[27] In 2010 he was appointed Knight Commander of the Order of Saint Lazarus.[28]