Editing Milk

{{Short description|Nutrient-rich liquid produced by mammals}}
{{about|the fluid produced by the mammary glands of mammals|the milk-like beverages derived from plants|Plant milk|other uses of the word|Milk&nbsp;(disambiguation)}}
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{{Use mdy dates|date=February 2023}}
[[File:Glass of Milk (33657535532).jpg|thumb|A glass of [[cow]] milk]]
[[File:Melkkarussell.jpg|thumb|Cows in a [[Rotolactor|rotary milking parlor]]]]
'''Milk''' is a white liquid [[food]] produced by the [[mammary gland]]s of [[lactating]] [[mammal]]s. It is the primary source of [[nutrition]] for young mammals (including [[breastfeeding|breastfed]] human infants) before they are able to [[digestion|digest]] solid food.<ref>{{cite journal |last1=Van Winckel |first1=M |last2=Velde |first2=SV |last3=De Bruyne |first3=R |last4=Van Biervliet |first4=S |title=Clinical Practice |journal=European Journal of Pediatrics |date=2011 |volume=170 |issue=12 |pages=1489–1494 |doi=10.1007/s00431-011-1547-x |pmid=21912895|s2cid=26852044  |issn=0340-6199 }}</ref> Milk contains many nutrients, including [[calcium]] and [[protein]], as well as [[lactose]] and [[saturated fat]];<ref>{{Cite web |date=July 2021 |title=Milk |url=https://www.hsph.harvard.edu/nutritionsource/milk/ |access-date=17 April 2024 |website=The Nutrition Source |publisher=Harvard T.H. Chan School of Public Health |language=en-us}}</ref> the enzyme [[lactase]] is needed to break down lactose. Immune factors and immune-modulating components in milk contribute to [[milk immunity]]. The first milk, which is called [[colostrum]], contains [[antibody|antibodies]] and immune-modulating components that [[milk immunity|strengthen]] the [[immune system]] against many diseases.

As an agricultural product, [[Milking|milk is collected]] from farm animals, mostly [[cattle]], on a [[dairy]]. It is used by humans as a [[drink]] and as the base ingredient for [[dairy products]]. The US [[Centers for Disease Control and Prevention|CDC]] recommends that children over the age of 12 months (the minimum age to stop giving [[breast milk]] or [[Baby formula|formula]]) should have two servings of milk products a day,<ref>{{cite journal |date=May 25, 2022 |title=Cow's Milk and Milk Alternatives |url=https://www.cdc.gov/nutrition/infantandtoddlernutrition/foods-and-drinks/cows-milk-and-milk-alternatives.html |url-status=live |journal=Centers for Disease Control and Prevention |archive-url=https://web.archive.org/web/20220313094327/https://www.cdc.gov/nutrition/InfantandToddlerNutrition/foods-and-drinks/cows-milk-and-milk-alternatives.html |archive-date=March 13, 2022 |access-date=March 10, 2022}}</ref> and more than six billion people worldwide consume milk and milk products.<ref name=":0" /> The ability for adult humans to digest milk relies on [[lactase persistence]], so [[Lactose intolerance|lactose intolerant]] individuals have trouble digesting lactose.

In 2011, [[Dairy farming|dairy farms]] produced around {{convert|730|e6tonne|e6ST|abbr=off|lk=in}} of milk<ref>{{cite web |title=Food Outlook{{nbsp}}– Global Market Analysis |date=May 2012 |publisher=Food and Agriculture Organization of the United Nations |pages=8, 51–54 |url=http://www.fao.org/docrep/015/al989e/al989e00.pdf |access-date=August 1, 2012 |archive-url=https://web.archive.org/web/20120522161025/http://www.fao.org/docrep/015/al989e/al989e00.pdf |archive-date=May 22, 2012 |url-status=live }}</ref> from 260 million dairy cows.<ref>{{cite news |title=World Dairy Cow Numbers |url=http://www.dairyco.org.uk/market-information/farming-data/cow-numbers/world-cow-numbers/ |newspaper=[FAO] |date=January 14, 2014 |access-date=March 23, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140323134129/http://www.dairyco.org.uk/market-information/farming-data/cow-numbers/world-cow-numbers/ |archive-date=March 23, 2014}}</ref> [[India]] is the world's largest producer of milk and the leading exporter of [[skimmed milk]] powder.<ref>{{cite web |url=http://www.dawn.com/news/1050700 |title=India emerging as a leading milk product exporter |author=Anand Kumar |work=Dawn |location=Pakistan |date=October 21, 2013 |access-date=June 3, 2015 |archive-url=https://web.archive.org/web/20150630165048/http://www.dawn.com/news/1050700 |archive-date=June 30, 2015 |url-status=live}}</ref><ref>{{cite news |url=http://articles.economictimes.indiatimes.com/2014-07-09/news/51247854_1_milk-powder-smp-exporters-milk-prices |title=Government scraps incentive on milk powder exports to check prices |department=Economic Times | work=Times of India | agency= Press Trust of India| date=9 July 2014  |access-date=June 3, 2015 |archive-url=https://web.archive.org/web/20150630120625/http://articles.economictimes.indiatimes.com/2014-07-09/news/51247854_1_milk-powder-smp-exporters-milk-prices |archive-date=June 30, 2015 |url-status=dead}}</ref> New Zealand, Germany, and the Netherlands are the largest exporters of milk products.<ref>{{cite web |title=Top Milk Exporting Countries |url=http://www.worldstopexports.com/top-milk-exporting-countries/ |access-date=July 3, 2019 |archive-date=July 21, 2020 |archive-url=https://web.archive.org/web/20200721184728/http://www.worldstopexports.com/top-milk-exporting-countries/ |url-status=live }}</ref> Between 750 and 900 million people live in dairy-farming households.<ref name=":0">{{cite book |title=Status and Prospects for Smallholder Milk Production: A Global Perspective |publisher=Food and Agriculture Organization of the United Nations |year=2010 |editor1-last=Hemme |editor1-first=T. |editor2-last=Otte |editor2-first=J. |url=http://www.fao.org/docrep/012/i1522e/i1522e00.pdf |access-date=December 1, 2011 |archive-url=https://web.archive.org/web/20120119183128/http://www.fao.org/docrep/012/i1522e/i1522e00.pdf |archive-date=January 19, 2012 |url-status=live}}</ref>

==Etymology and terminology==
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'')".<ref name="etymonline.com">{{cite web |url=http://www.etymonline.com/index.php?allowed_in_frame=0&search=milk |title=milk{{nbsp}}– Search Online Etymology Dictionary|website=www.etymonline.com|access-date=January 30, 2018|archive-url=https://web.archive.org/web/20170525161900/http://www.etymonline.com/index.php?allowed_in_frame=0&search=milk|archive-date=May 25, 2017|url-status=live}}</ref>

Since 1961, the term [[:wiktionary:milk#Noun|''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."<ref>{{Cite web |url=http://www.fao.org/fao-who-codexalimentarius/sh-proxy/en/?lnk=1&url=https%253A%252F%252Fworkspace.fao.org%252Fsites%252Fcodex%252FStandards%252FCODEX%2BSTAN%2B206-1999%252FCXS_206e.pdf |title=General Standard for the Use of Dairy Terms 206-1999 |last=Codex Alimentarius Commission |archive-url=https://web.archive.org/web/20170709194642/http://www.fao.org/fao-who-codexalimentarius/sh-proxy/en/?lnk=1&url=https%3A%2F%2Fworkspace.fao.org%2Fsites%2Fcodex%2FStandards%2FCODEX+STAN+206-1999%2FCXS_206e.pdf |archive-date=July 9, 2017 |url-status=live}}</ref> The term [[:wiktionary:dairy#Noun|''dairy'']] refers to animal milk and animal milk production.

==Types of consumption==
There are two distinct categories of milk consumption: all infant mammals drink milk directly from their mothers' bodies, and it is their primary source of nutrition; and humans obtain milk from other mammals for consumption by humans of all ages, as one component of a varied diet.

===Nutrition for infant mammals===
{{Further|Breastfeeding|Lactation}}
[[File:Woman breastfeeding an infant.jpg|thumb|upright|Breastfeeding to provide a mother's milk]]
[[File:Goat kid feeding on mothers milk.jpg|thumb|A goat kid feeding on its mother's milk]]
In almost all mammals, milk is fed to [[infant]]s through [[breastfeeding]], either directly or by [[Breastfeeding#Expressed milk|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.<ref>{{Cite journal |last1=Uruakpa |first1=F.O. |last2=Ismond |first2=M.A.H. |last3=Akobundu |first3=E.N.T. |doi=10.1016/S0271-5317(02)00373-1 |title=Colostrum and its benefits: A review |journal=Nutrition Research |volume=22 |issue=6 |pages=755–67 |year=2002}}</ref> The makeup of the colostrum and the period of secretion varies from species to species.<ref>{{cite book |title=Saunders Comprehensive Veterinary Dictionary |year=2007 |publisher=Saunders Elsevierv |vauthors=Blood DC, Studdert VP, Gay CC |place=St. Louis, MO |isbn=978-0-7020-2789-5 |url=https://archive.org/details/saunderscomprehe00doug}}</ref>

For humans, the [[World Health Organization]] recommends exclusive breastfeeding for six months and breastfeeding in addition to other food for up to two years of age or more.<ref>[https://www.who.int/nutrition/topics/infantfeeding_recommendation/en/index.html The World Health Organization's infant feeding recommendation] {{Webarchive|url=https://web.archive.org/web/20130411034406/http://www.who.int/nutrition/topics/infantfeeding_recommendation/en/index.html |date=April 11, 2013 }} [[World Health Organization|WHO]], based on "Global strategy on infant and young child feeding" (2002). Retrieved February 8, 2013.</ref> In some cultures it is common to breastfeed children for three to five years, and the period may be longer.<ref>{{cite magazine |author-link=Katherine A. Dettwyler |first=Katherine A. |last=Dettwyler |url=https://www.questia.com/read/1P3-17039763/when-to-wean |title=When to Wean |url-access=subscription |magazine=[[Natural History (magazine)|Natural History]] |date=October 1997 |access-date=February 8, 2013 |archive-url=https://web.archive.org/web/20130606003237/http://www.questia.com/read/1P3-17039763/when-to-wean |archive-date=June 6, 2013 |url-status=live}}</ref>

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]].<ref>{{Cite journal |last1=Basnet |first1=S. |last2=Schneider |first2=M. |last3=Gazit |first3=A. |last4=Mander |first4=G. |last5=Doctor |first5=A. |title=Fresh Goat's Milk for Infants: Myths and Realities{{nbsp}}– A Review |journal=Pediatrics |volume=125 |issue=4 |date=April 2010 |pages=e973–77 |doi=10.1542/peds.2009-1906 |pmid=20231186|s2cid=31557323 }}</ref>

===Food product for humans===
[[File:Cow female black white.jpg|thumb| The [[Holstein Friesian cattle|Holstein Friesian cow]] is the dominant breed in industrialized dairy farms today.]]
[[File:A bowl of milk for the shaman rite. Buryatia. Russia.png|thumb|A bowl of milk for the shaman rite; [[Buryatia]], [[Russia]]]]
[[File:World Production Of Bovine Milk.svg|thumb|World production of cow milk]]
In many cultures, especially in [[Western world|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 northwestern Europe that enabled the [[Lactase persistence|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.<ref name="Nature Milk">{{cite journal |doi=10.1038/500020a |title=Archaeology: The milk revolution |last=Curry |first=Andrew |date=July 31, 2013 |journal=Nature |volume=500 |pages=20–22 |issue=7460 |pmid=23903732 |bibcode=2013Natur.500...20C|doi-access=free}}</ref> 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]].<ref>{{cite web |url=https://www.cdc.gov/nutrition/everyone/basics/fat/saturatedfat.html |title=Nutrition for Everyone: Basics: Saturated Fat{{nbsp}}– DNPAO |publisher=[[Centers for Disease Control and Prevention]] |access-date=June 16, 2017 |archive-url=https://web.archive.org/web/20140129222042/http://www.cdc.gov/nutrition/everyone/basics/fat/saturatedfat.html |archive-date=January 29, 2014 |url-status=dead }}</ref><ref>{{cite web |url=http://www.nhs.uk/Livewell/Goodfood/Pages/Eat-less-saturated-fat.aspx |title=Eat less saturated fat |publisher=[[National Health Service]] |date=April 27, 2018 |access-date=April 25, 2015 |archive-url=https://web.archive.org/web/20150424075505/http://www.nhs.uk/livewell/goodfood/pages/eat-less-saturated-fat.aspx |archive-date=April 24, 2015 |url-status=live}}</ref> The sugar lactose is found only in milk, and possibly in [[forsythia]] flowers and a few tropical shrubs.<ref>{{Cite journal |last1=Adam |first1=Ana C. |last2=Rubio-Texeira |first2=Marta |last3=Polaina |first3=Julio |date=February 10, 2005 |title=Lactose: The Milk Sugar from a Biotechnological Perspective |url=https://doi.org/10.1080/10408690490931411 |journal=Critical Reviews in Food Science and Nutrition |volume=44 |issue=7–8 |pages=553–557 |doi=10.1080/10408690490931411 |pmid=15969327 |s2cid=24005833 |issn=1040-8398|url-access=subscription }}</ref> Lactase, the enzyme needed to digest lactose, reaches its highest levels in the human small intestine immediately after birth, and then begins a slow decline unless milk is consumed regularly.<ref name="On Food and Cooking">{{Cite book |last=McGee |first=Harold |author-link=Harold McGee |title=On Food and Cooking: The Science and Lore of the Kitchen |orig-year=1984 |year=2004 |publisher=Scribner |edition=2nd |location=New York |isbn=978-0-684-80001-1 |chapter-url=https://books.google.com/books?id=bKVCtH4AjwgC&pg=PA7 |pages=7–67 |chapter=Milk and Dairy Products |access-date=October 19, 2020 |archive-date=December 26, 2020 |archive-url=https://web.archive.org/web/20201226095557/https://books.google.com/books?id=bKVCtH4AjwgC&pg=PA7 |url-status=live }}</ref> Those groups who continue to tolerate milk have often exercised great creativity in using the milk of [[domestication|domesticated]] [[ungulate]]s, not only cattle, but also sheep, goats, [[yak]]s, [[water buffalo]], horses, [[reindeer]] and [[camel milk|camels]]. India is the largest producer and consumer of cattle milk and buffalo milk in the world.<ref>{{cite web |url=http://www.indiadairy.com/ind_world_number_one_milk_producer.html |title=World's No 1 Milk Producer |publisher=Indiadairy.com |access-date=August 28, 2010 |archive-url=https://web.archive.org/web/20100516142829/http://www.indiadairy.com/ind_world_number_one_milk_producer.html |archive-date=May 16, 2010 |url-status=dead}}</ref>
{| class="sortable wikitable" style="margin:auto"
|+Per capita consumption of milk and milk products in selected countries in 2011<ref name="intro">{{cite web |last=Goff |first=Douglas |title=Introduction to Dairy Science and Technology: Milk History, Consumption, Production, and Composition: World-wide Milk Consumption and Production |url=https://www.uoguelph.ca/foodscience/book-page/world-wide-milk-consumption-and-production |work=Dairy Science and Technology |publisher=University of Guelph |access-date=November 12, 2014 |archive-url=https://web.archive.org/web/20141112222438/https://www.uoguelph.ca/foodscience/book-page/world-wide-milk-consumption-and-production |archive-date=November 12, 2014 |url-status=dead}}</ref>
|-
! Country !! Milk (liters) !! Cheese (kg) !! Butter (kg)
|-
| {{IRL}} || 135.6 || 6.7 || 2.4
|-
| {{FIN}} || 127.0 || 22.5 || 4.1
|-
| {{GBR}} || 105.9 || 10.9 || 3.0
|-
| {{AUS}} || 105.3 || 11.7 || 4.0
|-
| {{SWE}} || 90.1 || 19.1 || 1.7
|-
| {{CAN}} || 78.4 || 12.3 || 2.5
|-
| {{USA}} || 75.8 || 15.1 || 2.8
|-
| {{EUR}} || 62.8 || 17.1 || 3.6
|-
| {{BRA}} || 55.7 || 3.6 || 0.4
|-
| {{FRA}} || 55.5 || 26.3 || 7.5
|-
| {{ITA}} || 54.2 || 21.8 || 2.3
|-
| {{DEU}} || 51.8 || 22.9 || 5.9
|-
| {{GRE}} || 49.1 || 23.4 || 0.7
|-
| {{NED}} || 47.5 || 19.4 || 3.3
|-
| {{IND}} || 39.5 || – || 3.5
|-
| {{CHN}} || 9.1 || – || 0.1
|}

==History==
[[File:Bundesarchiv Bild 183-2004-0708-501, Berlin, Milch von Bolle in der Pause.jpg|thumb|upright|Drinking milk in Germany in 1932]]
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{{nbsp}}BC in [[Mesopotamia]]<ref>{{cite book |last=Bellwood |first=Peter |title=First Farmers: the origins of agricultural societies |year=2005 |publisher=Blackwell Publishing |location=Malden, MA |isbn=978-0-631-20566-1 |pages=44–68 |chapter=The Beginnings of Agriculture in Southwest Asia}}</ref> to 3500–3000{{nbsp}}BC in the Americas.<ref>{{cite book |last=Bellwood |first=Peter |title=First Farmers: the origins of agricultural societies |year=2005 |publisher=Blackwell Publishing |location=Malden, MA |isbn=978-0-631-20566-1 |pages=146–79 |chapter=Early Agriculture in the Americas}}</ref> People first domesticated the most important dairy animals&nbsp;– cattle, sheep and goats&nbsp;– in Southwest Asia, although domestic cattle had been independently derived from wild [[aurochs]] populations several times since.<ref>{{Cite journal |title=The origin of European cattle: Evidence from modern and ancient DNA |doi=10.1073/pnas.0509210103 |journal=Proceedings of the National Academy of Sciences |volume=103 |issue=21 |pages=8113–18 |year=2006 |pmid=16690747 |pmc=1472438 |last1=Beja-Pereira |first1=A. |last2=Caramelli |first2=D. |last3=Lalueza-Fox |first3=C. |last4=Vernesi |first4=C. |last5=Ferrand |first5=N. |last6=Casoli |first6=A. |last7=Goyache |first7=F. |last8=Royo |first8=L.J. |last9=Conti |first9=S. | last10 = Lari | first10 = M. |last11=Martini |first11=A. |last12=Ouragh |first12=L. |last13=Magid |first13=A. |last14=Atash |first14=A. |last15=Zsolnai |first15=A. |last16=Boscato |first16=P. |last17=Triantaphylidis |first17=C. |last18=Ploumi |first18=K. |last19=Sineo |first19=L. | last20 = Mallegni | first20 = F. |last21=Taberlet |first21=P. |last22=Erhardt |first22=G. |last23=Sampietro |first23=L. |last24=Bertranpetit |first24=J. |last25=Barbujani |first25=G. |last26=Luikart |first26=G. |last27=Bertorelle |first27=G. |bibcode=2006PNAS..103.8113B|doi-access=free}}</ref> 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.<ref>{{cite book |last=Sherratt |first=Andrew |title=Pattern of the Past: Studies in honour of David Clarke |year=1981 |publisher=Cambridge University Press |location=Cambridge |isbn=978-0-521-22763-6 |pages=261–305|editor1-last=Hodder|editor1-first=I.|editor2-last=Isaac|editor2-first=G.|editor3-last=Hammond|editor3-first=N. |chapter=Plough and pastoralism: aspects of the secondary products revolution}}</ref> 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.<ref>{{cite journal |last1=Vigne |first2=J.-D. |last2=Helmer |first1=D. |title=Was milk a 'secondary product' in the Old World Neolithisation process? Its role in the domestication of cattle, sheep and goats |journal=Anthropozoologica |year=2007 |volume=42 |issue=2 |pages=9–40 |url=http://www.mnhn.fr/museum/front/medias/publication/12514_009_040.pdf |url-status=dead |archive-url=https://web.archive.org/web/20130510010227/http://www.mnhn.fr/museum/front/medias/publication/12514_009_040.pdf |archive-date=May 10, 2013}}</ref><ref>{{Cite journal |last1=Evershed |first1=R.P. |last2=Payne |first2=S. |last3=Sherratt |first3=A.G. |last4=Copley |first4=M.S. |last5=Coolidge |first5=J. |last6=Urem-Kotsu |first6=D. |last7=Kotsakis |first7=K. |last8=Ozdoğan |first8=M. |last9=Ozdoğan |first9=A.E. |doi=10.1038/nature07180 | last10 = Nieuwenhuyse | first10 = O. |last11=Akkermans |first11=P.M.M.G. |last12=Bailey |first12=D. |last13=Andeescu |first13=R.R. |last14=Campbell |first14=S. |last15=Farid |first15=S. |last16=Hodder |first16=I. |last17=Yalman |first17=N. |last18=Ozbaşaran |first18=M. |last19=Biçakci |first19=E. | last20 = Garfinkel | first20 = Y. |last21=Levy |first21=T. |last22=Burton |first22=M.M. |title=Earliest date for milk use in the Near East and southeastern Europe linked to cattle herding |journal=Nature |volume=455 |issue=7212 |pages=528–31 |year=2008 |pmid=18690215 |bibcode=2008Natur.455..528E |s2cid=205214225}}</ref>

From Southwest Asia domestic dairy animals spread to Europe (beginning around 7000 BC but did not reach Britain and Scandinavia until after 4000 BC),<ref>{{cite book |last=Price |first=T.D. |title=Europe's First Farmers |year=2000 |publisher=Cambridge University Press |location=Cambridge |isbn=978-0-521-66203-1 |pages=1–18 |editor=T.D. Price |chapter=Europe's first farmers: an introduction}}</ref> and South Asia (7000–5500&nbsp;BC).<ref>{{cite book |last=Meadow |first=R.H. |title=The origins and spread of agriculture and pastoralism in Eurasia |year=1996 |publisher=UCL Press |location=London |isbn=978-1-85728-538-3 |pages=390–412 |editor=D.R. Harris |chapter=The origins and spread of agriculture and pastoralism in northwestern South Asia}}</ref> The first farmers in central Europe<ref>{{cite journal |last=Craig |first=Oliver E. |author2=John Chapman |author3=Carl Heron |author4=Laura H. Willis |author5=László Bartosiewicz |author6=Gillian Taylor |author7=Alasdair Whittle |author8=Matthew Collins |title=Did the first farmers of central and eastern Europe produce dairy foods? |journal=Antiquity |year=2005 |volume=79 |issue=306 |pages=882–94 |hdl=10149/136330 |doi=10.1017/S0003598X00115017 |arxiv=0706.4406|s2cid=53378351 }}</ref> and Britain<ref>{{Cite journal |last1=Copley |first1=M.S. |last2=Berstan |first2=R. |last3=Mukherjee |first3=A.J. |last4=Dudd |first4=S.N. |last5=Straker |first5=V. |last6=Payne |first6=S. |last7=Evershed |first7=R.P. |doi=10.1016/j.jas.2004.08.006 |title=Dairying in antiquity. III. Evidence from absorbed lipid residues dating to the British Neolithic |journal=Journal of Archaeological Science |volume=32 |issue=4 |pages=523–56 |year=2005|bibcode=2005JArSc..32..523C }}</ref> milked their animals. [[Pastoralism|Pastoral]] and [[Nomadic pastoralism|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]].<ref>{{cite book |last=Anthony |first=D.W. |title=The Horse, the Wheel, and Language |year=2007 |publisher=Princeton University Press |location=Princeton, NJ |isbn=978-0-691-05887-0}}</ref> Sheep and goats were introduced to Africa from Southwest Asia, but African cattle may have been independently domesticated around 7000–6000{{nbsp}}BC.<ref>{{cite book |last=Gifford-Gonzalez |first=D. |title=African archaeology: a critical introduction |year=2004 |publisher=Blackwell Publishing |location=Malden, MA |isbn=978-1-4051-0155-4 |pages=187–224 |editor=A.B. Stahl |chapter=Pastoralism and its Consequences}}</ref> Camels, domesticated in central Arabia in the fourth millennium BC, have also been used as dairy animals in North Africa and the Arabian Peninsula.<ref>{{Cite journal |last1=Peters |first1=J. |title=The dromedary: Ancestry, history of domestication and medical treatment in early historic times |journal=Tierarztliche Praxis. Ausgabe G, Grosstiere/Nutztiere |volume=25 |issue=6 |pages=559–65 |year=1997 |pmid=9451759}}</ref> The earliest Egyptian records of burn treatments describe burn dressings using milk from mothers of male babies.<ref name="Pećanac-">{{Cite journal |last1=Pećanac |first1=M. |last2=Janjić |first2=Z. |last3=Komarcević |first3=A. |last4=Pajić |first4=M. |last5=Dobanovacki |first5=D. |last6=Misković |first6=SS. |title=Burns treatment in ancient times |journal=Med Pregl |volume=66 |issue=5–6 |pages=263–67 |year=2013 |doi=10.1016/s0264-410x(02)00603-5 |pmid=23888738}}</ref> 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 the water generally available.<ref>
{{cite book |last=Valenze |first=D.M. |title=Milk: a local and global history |year=2011 |publisher=Yale University Press |location=New Haven |isbn=978-0-300-11724-0 |page=34 |chapter=Virtuous White Liquor in the Middle Ages |chapter-url=https://archive.org/details/milklocalglobalh00vale_0}}</ref> Incorrectly thought to be blood diverted from the womb to the breast, it was also known as "white blood", and treated like blood for religious dietary purposes and in [[humoral theory]].<ref>{{cite book |first=Lawrence Trevelyan |last=Weaver |title=White Blood: A History of Human Milk |publisher=Unicorn Publishing Group |year=2021 |isbn=978-1-913491-26-0}}</ref>

[[James Rosier|James Rosier's]] record of the 1605 voyage made by [[George Weymouth]] to New England reported that the [[Wabanaki Confederacy|Wabanaki]] people Weymouth captured in Maine milked "Rain-Deere and Fallo-Deere." But Journalist [[Avery Yale Kamila]] and food historians said Rosier "misinterpreted the evidence." Historians report the Wabanaki did not domesticate deer.<ref>{{Cite web |last=Kamila |first=Avery Yale |date=November 8, 2020 |title=Americans have been enjoying nut milk and nut butter for at least 4 centuries |url=https://www.pressherald.com/2020/11/08/vegan-kitchen-americans-have-been-enjoying-nut-milk-and-nut-butter-for-at-least-4-centuries/ |access-date=January 6, 2021 |website=Portland Press Herald |archive-date=January 8, 2021 |archive-url=https://web.archive.org/web/20210108211852/https://www.pressherald.com/2020/11/08/vegan-kitchen-americans-have-been-enjoying-nut-milk-and-nut-butter-for-at-least-4-centuries/ |url-status=live }}</ref><ref>{{Cite web |title=Wabanaki Enjoying Nut Milk and Butter for Centuries |url=https://www.atowi.org/press/wabanaki-enjoying-nut-milk-and-butter-for-centuries |access-date=January 7, 2021 |website=Atowi |language=en-US |archive-date=January 9, 2021 |archive-url=https://web.archive.org/web/20210109040429/https://www.atowi.org/press/wabanaki-enjoying-nut-milk-and-butter-for-centuries |url-status=live }}</ref> The tribes of the northern woodlands have historically been making [[Plant milk|nut milk]].<ref>{{Cite web |last=Diemer-Eaton |first=Jessica |date=2014 |title=Food Nuts of the Eastern Woodlands Native Peoples |url=http://www.woodlandindianedu.com/foodnuts.html |access-date=January 7, 2021 |website=Woodland Indian Educational Programs |archive-date=November 25, 2020 |archive-url=https://web.archive.org/web/20201125031121/http://www.woodlandindianedu.com/foodnuts.html |url-status=live }}</ref> Cows were imported to [[New England]] in 1624.<ref>{{Cite journal |last=Bowling |first=G. A. |date=February 1, 1942 |title=The Introduction of Cattle into Colonial North America* |journal=Journal of Dairy Science |language=en |volume=25 |issue=2 |pages=129–154 |doi=10.3168/jds.S0022-0302(42)95275-5 |issn=0022-0302|doi-access=free}}</ref>

===Industrialization===
[[File:SR 4409 6 Wheeled Milk Wagon Didcot Railway Centre.jpg|thumb|right|Preserved [[Express Dairies]] three-axle milk tank wagon at the [[Didcot Railway Centre]], based on an [[Southern Railway (Great Britain)|SR]] chassis]]
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.<ref name="Atkins">{{cite journal |title=The Growth of London's Railway Milk Trade, c.{{nbsp}}1845–1914 |author=P.J. Atkins |journal=Journal of Transport History |volume=ss-4 |issue=4 |pages=208–26 |year=1978 |url=https://www.academia.edu/3165543 |doi=10.1177/002252667800400402 |s2cid=158443104 |access-date=December 3, 2017 |archive-date=February 16, 2021 |archive-url=https://web.archive.org/web/20210216185904/https://www.academia.edu/3165543/The_growth_of_London_s_railway_milk_trade_c_1845_1914 |url-status=live }}</ref> 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 {{convert|25|e6impgal|e6l e6USgal|abbr=off}} annually.<ref>{{cite web |url=http://www.dairyco.org.uk/talking-to-the-public/talking-to-schools/providing-school-milk/the-history-of-milk/ |title=The History of Milk |publisher=DairyCo |url-status=dead |archive-url=https://web.archive.org/web/20140116060017/http://www.dairyco.org.uk/talking-to-the-public/talking-to-schools/providing-school-milk/the-history-of-milk/ |archive-date=January 16, 2014}}</ref> The milk trade grew slowly through the 1860s, but went through a period of extensive, structural change in the 1870s and 1880s.

[[File:Aesthetic Milk Vehicle.jpg|thumb|Milk transportation in [[Salem, Tamil Nadu]]]]
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. [[Public Health Acts|Legislation in 1875]] made the adulteration of milk illegal{{nbsp}}– 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.<ref name="Atkins" /> Milk was analyzed for infection with [[tuberculosis]]. In 1907 180 samples were tested in Birmingham and 13.3% were found to be infected.<ref>{{cite book |last1=Otter |first1=Chris |title=Diet for a large planet |date=2020 |publisher=University of Chicago Press |location=USA |isbn=978-0-226-69710-9 |page=115 }}</ref>

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 Dairies|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.<ref name="milk history"/> In 1932, [[plastic-coated paper]] milk cartons were introduced commercially.<ref name="milk history"/>

In 1863, French chemist and biologist [[Louis Pasteur]] invented pasteurization, a method of killing harmful bacteria in beverages and food products.<ref name="milk history">[https://archive.today/20130102002120/http://inventors.about.com/od/mstartinventions/a/milk.htm "The History Of Milk"], [[About.com]]. Retrieved August 13, 2010.</ref> He developed this method while on summer vacation in [[Arbois]], to remedy the frequent acidity of the local wines.<ref name=VR1928>{{cite book |pages=113–14 |url=https://books.google.com/books?id=rQ_hjAuH9xEC&pg=PA113 |title=Life of Pasteur 1928 |isbn=978-0-7661-4352-4 |last1=Vallery-Radot |first1=René |year=2003 | publisher=Kessinger |access-date=November 22, 2015 |archive-url=https://web.archive.org/web/20160101072908/https://books.google.com/books?id=rQ_hjAuH9xEC&pg=PA113 |archive-date=January 1, 2016 |url-status=live}}</ref> He found out experimentally that it is sufficient to heat a young wine to only about {{convert|50|-|60|°C|°F}} for a brief time to kill the microbes, and that the wine could be nevertheless properly [[aging of wine|aged]] without sacrificing the final quality.<ref name=VR1928 /> In honor of Pasteur, the process became known as "pasteurization". Pasteurization was originally used as a way of preventing wine and beer from souring.<ref>Carlisle, Rodney (2004). ''Scientific American Inventions and Discoveries'', p. 357. John Wiley & Songs, Inc., New Jersey. {{ISBN|0-471-24410-4}}.</ref> Commercial pasteurizing equipment was produced in Germany in the 1880s, and producers adopted the process in [[Copenhagen]] and [[Stockholm]] by 1885.<ref>{{cite journal |title=The pasteurization of England: the science, culture and health implications of food processing, 1900–1950 |journal=Food, Science, Policy and Regulation in the 20th Century |author=Peter Atkins |date=January 2000 |url=https://www.academia.edu/3161171 |access-date=December 3, 2017 |archive-date=February 16, 2021 |archive-url=https://web.archive.org/web/20210216190218/https://www.academia.edu/3161171/The_pasteurization_of_England_the_science_culture_and_health_implications_of_food_processing_1900_1950 |url-status=live }}</ref><ref name="HwangHuang2009">{{cite book |last1=Hwang |first1=Andy |last2=Huang |first2=Lihan |title=Ready-to-Eat Foods: Microbial Concerns and Control Measures |url=https://books.google.com/books?id=AbOrQP33U6EC&pg=PA88 |access-date=April 19, 2011 |date=January 31, 2009 |publisher=CRC Press |isbn=978-1-4200-6862-7 |page=88 |archive-url=https://web.archive.org/web/20130602041236/http://books.google.com/books?id=AbOrQP33U6EC&pg=PA88 |archive-date=June 2, 2013 |url-status=live}}</ref>

==Sources==
[[File:Farm in sogn og fjordane.JPG|thumb|Modern [[dairy farm]] in Norway]]
All mammal species have females who can produce milk for some time after giving birth. Cow milk dominates the amount of milk produced. In 2011, FAO estimates 85% of all milk worldwide was produced from cows.<ref name=gs12>{{cite web |title=Milk availability{{nbsp}}– Trends in production and demand and medium-term outlook |author=Gerosa and Skoet |publisher=[[Food and Agriculture Organization]], United Nations |year=2012 |url=http://www.fao.org/docrep/015/an450e/an450e00.pdf |access-date=August 1, 2012 |archive-url=https://web.archive.org/web/20120906163434/http://www.fao.org/docrep/015/an450e/an450e00.pdf |archive-date=September 6, 2012 |url-status=live }}</ref> Human milk is not produced or distributed industrially or commercially; however, [[human milk bank]]s collect donated human [[breastmilk]] and redistribute it to infants who may benefit from human milk for various reasons (premature neonates, babies with allergies, [[Inborn error of metabolism|metabolic diseases]], etc.) but who cannot breastfeed.<ref>[https://www.hmbana.org/ Why Bank Milk?] {{Webarchive|url=https://web.archive.org/web/20130807233928/https://www.hmbana.org/ |date=August 7, 2013 }} Human Milk Banking Association of North America</ref> Actual inability to produce enough milk is rare, with studies showing that mothers from malnourished regions still produce amounts of milk of similar quality to that of mothers in developed countries.<ref>Prentice, A.M., Paul, A., Prentice, A., Black, A., Cole, T., & Whitehead, R. (1986). Cross – cultural differences in lactational performance. In Maternal Environmental Factors in Human Lactation. Human Lactation 2, pp. 13 = 44 [Hamosh, M., & Goldman, A.S. (eds)]. New York: Plenum Press.</ref><ref name="BeckerSmith2015">{{cite journal |vauthors=Becker GE, Smith HA, Cooney F |date=February 2015 |editor1-last=Becker |editor1-first=Genevieve E |title=Methods of milk expression for lactating women |journal=The Cochrane Database of Systematic Reviews |issue=2 |pages=CD006170 |doi=10.1002/14651858.CD006170.pub4 |pmid=25722103}}</ref><ref>{{Cite journal |last1=Srinivasjois |first1=Ravisha |last2=Sharma |first2=Ajay |last3=Shah |first3=Prakesh |last4=Kava |first4=Maina |date=July 2011 |title=Effect of induction of meconium evacuation using per rectal laxatives on neonatal hyperbilirubinemia in term infants: a systematic review of randomized controlled trials |journal=Indian Journal of Medical Sciences |volume=65 |issue=7 |pages=278–285 |doi=10.4103/0019-5359.107388 |doi-broken-date=November 1, 2024 |issn=1998-3654 |pmid=23422701 |doi-access=free}}</ref> There are many reasons a mother may [[Low milk supply|not produce enough breast milk]].<ref>{{Cite web |title=Low milk supply: What causes it? |url=https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/expert-answers/low-milk-supply/faq-20058148 |access-date=2022-04-28 |website=Mayo Clinic |language=en |archive-date=April 28, 2022 |archive-url=https://web.archive.org/web/20220428110742/https://www.mayoclinic.org/healthy-lifestyle/infant-and-toddler-health/expert-answers/low-milk-supply/faq-20058148 |url-status=live }}</ref><ref>{{Cite journal |last=Asztalos |first=Elizabeth V. |date=2018-05-12 |title=Supporting Mothers of Very Preterm Infants and Breast Milk Production: A Review of the Role of Galactogogues |journal=Nutrients |volume=10 |issue=5 |pages=600 |doi=10.3390/nu10050600 |issn=2072-6643 |pmc=5986480 |pmid=29757199 |doi-access=free}}</ref><ref>{{Cite web |last=KellyMom |date=2011-08-02 |title=Fenugreek Seed for Increasing Milk Supply - KellyMom.com |url=https://kellymom.com/bf/can-i-breastfeed/herbs/fenugreek/,%20https://kellymom.com/bf/can-i-breastfeed/herbs/fenugreek/ |access-date=2023-12-18 |language=en-US |archive-date=January 29, 2024 |archive-url=https://web.archive.org/web/20240129200337/https://kellymom.com/bf/can-i-breastfeed/herbs/fenugreek/ |url-status=live }}</ref> The amount of milk produced depends on how often the mother is nursing and/or [[Breast pump|pumping]]: the more the mother nurses her baby or pumps, the more milk is produced.<ref name="mayo1">{{cite web |date=2010-03-13 |title=Breast-feeding: Pumping and maintaining your milk supply |url=http://www.mayoclinic.com/health/breast-feeding/FL00120 |access-date=2011-10-26 |publisher=MayoClinic.com |archive-date=August 26, 2019 |archive-url=https://web.archive.org/web/20190826135228/http://www.mayoclinic.com/health/breast-feeding/FL00120 |url-status=live }}</ref><ref>{{cite web |date=2010-01-01 |title=Breast milk: Increasing supply – iVillage |url=http://parenting.ivillage.com/newborn/nbreastfeed/0,,456z,00.html |url-status=dead |access-date=2011-10-26 |publisher=Parenting.ivillage.com |archive-date=May 14, 2010 |archive-url=https://web.archive.org/web/20100514140816/http://parenting.ivillage.com/newborn/nbreastfeed/0,,456z,00.html }}</ref><ref>{{Cite web |last=KellyMom |date=2016-08-10 |title=thương hiệu |url=https://ganolamum.vn/ |access-date=2023-12-18 |language=en-US |archive-date=December 23, 2023 |archive-url=https://web.archive.org/web/20231223212359/https://ganolamum.vn/ |url-status=live }}</ref><ref>{{cite web |title=How Breast Milk is Produced |url=http://www.babies.sutterhealth.org/breastfeeding/bf_production.html |access-date=2011-10-26 |publisher=Babies.sutterhealth.org |archive-date=September 16, 2019 |archive-url=https://web.archive.org/web/20190916161254/http://www.babies.sutterhealth.org/breastfeeding/bf_production.html |url-status=live }}</ref>

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 [[automatic milking|automated milking]] equipment produces the vast majority of milk in [[Developed country|developed countries]]. [[Dairy cattle]], such as the [[Holstein cattle|Holstein]], have been bred selectively for increased milk production. About 90% of the dairy cows in the United States and 85% in [[UK|Great Britain]] are Holsteins.<ref name="On Food and Cooking"/> Other dairy cows in the United States include [[Ayrshire cattle|Ayrshire]], [[Brown Swiss]], [[Guernsey cattle|Guernsey]], [[Jersey cattle|Jersey]] and [[Milking Shorthorn]] (Dairy Shorthorn).

===Other animal-based sources===
{{multiple image|total_width=300
|title = Other significant sources of milk
| image1 = Goat family.jpg|width1=1600|height1=1067|caption1=Goats (2% of world's milk)
| image2 = Water buffaloes Sri Lanka grazing.jpg|width2=3264|height2=2448|caption2=Buffaloes (11%)
}}
Aside from cattle, many kinds of livestock provide milk used by humans for dairy products. These animals include [[Water buffalo#Dairy products|water buffalo]], [[Goat milk|goat]], [[sheep milk|sheep]], [[camel milk|camel]], [[Ass's milk (Donkey's milk)|donkey]], [[horse#Products|horse]], reindeer and yak. The first four respectively produced about 11%, 2%, 1.4% and 0.2% of all milk worldwide in 2011.<ref name=gs12/>

In Russia and Sweden, small [[moose milk|moose dairies]] also exist.<ref>{{cite news |last1=Grandell |first1=Tommy |title=Sweden's healthy moose cheese is a prized delicacy |url=https://www.goupstate.com/article/NC/20040707/news/605167766/SJ |access-date=January 24, 2020 |work=GoUpstate |date=July 7, 2004 |language=en |archive-date=January 25, 2021 |archive-url=https://web.archive.org/web/20210125184131/https://www.goupstate.com/article/NC/20040707/news/605167766/SJ |url-status=live }}</ref>

According to the US National Bison Association, [[American bison]] (also called American buffalo) are not milked commercially;<ref>{{cite web |url=http://www.bisoncentral.com/index.php?c=63&d=73&a=1022&w=2&r=Y|archive-url=https://web.archive.org/web/20060211091834/http://bisoncentral.com/index.php?c=63&d=73&a=1022&w=2&r=Y|url-status=dead|archive-date=February 11, 2006 |title=About Bison: Frequently Asked Questions |publisher=National Bison Association |access-date=August 16, 2009}}</ref> 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<ref>{{Cite book |last=Allen |first=Joel Asaph |title=History of the American Bison: bison americanus |editor=Elliott Coues, Secretary of the Survey |publisher=Department of the Interior, United States Geological Survey, Government Printing Office |location=Washington, DC |date=June 1877 |series=extracted from the 9th Annual Report of the United States Geological Survey (1875) |pages=585–86 |chapter=Part II., Chapter 4. Domestication of the Buffalo |oclc=991639 |chapter-url=https://books.google.com/books?id=oj04AAAAMAAJ&pg=PA585 |access-date=August 16, 2009 |archive-date=September 3, 2021 |archive-url=https://web.archive.org/web/20210903191101/https://books.google.com/books?id=oj04AAAAMAAJ&pg=PA585 |url-status=live }}</ref> and during the development of commercial [[Beefalo]] in the 1970s and 1980s.<ref>{{Cite journal |date=March–April 1981 |title=The Basics of Beefalo Raising |journal=[[Mother Earth News]] |first=George |last=O'Connor |issue=68 |url=http://www.motherearthnews.com/Sustainable-Farming/1981-03-01/The-Basics-of-Beefalo-Raising.aspx |archive-url=https://web.archive.org/web/20070504113756/http://www.motherearthnews.com/Sustainable-Farming/1981-03-01/The-Basics-of-Beefalo-Raising.aspx |archive-date=May 4, 2007 |access-date=February 8, 2011}}</ref>

[[Swine]] are almost never milked, even though [[Pig milk|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 cannot store their milk as cows can.<ref>{{Cite news |url=https://www.nrc.nl/nieuws/2010/06/22/waarom-drinken-we-de-melk-van-varkens-niet-11909380-a977345 |title=Waarom drinken we de melk van varkens niet? |website=NRC |date=June 22, 2010 |access-date=December 31, 2017 |archive-date=November 6, 2020 |archive-url=https://web.archive.org/web/20201106113242/https://www.nrc.nl/nieuws/2010/06/22/waarom-drinken-we-de-melk-van-varkens-niet-11909380-a977345 |url-status=live |last1=Bronzwaer |first1=Stijn }}</ref> A few pig farms do sell pig cheese as a novelty item; these cheeses are exceedingly expensive.<ref>{{cite news |url=https://www.plezierindekeuken.nl/nieuw-en-peperduur-kaas-van-varkensmelk/ |title=Nieuw (en peperduur): kaas van varkensmelk{{nbsp}}– Plezier in de Keuken|newspaper=Plezier in de Keuken|date=August 26, 2015|access-date=January 30, 2018|archive-url=https://web.archive.org/web/20180101083656/https://www.plezierindekeuken.nl/nieuw-en-peperduur-kaas-van-varkensmelk/|archive-date=January 1, 2018|url-status=live}}</ref>

==Production worldwide==
{{Main|List of countries by milk production|Dairy farming}}
{{stack begin | float=left}}
{|class="wikitable sortable"
|+ Largest milk producers in the world<br />in 2018<ref>{{cite web |url=http://www.fao.org/3/ca3879en/ca3879en.pdf |title=Dairy Market Review – Food and Agriculture Organization of the United Nations |publisher=[[FAO|UN Food & Agriculture Organization]]|access-date=June 28, 2020|url-status=dead|archive-url=https://web.archive.org/web/20190711085003/http://www.fao.org/3/ca3879en/ca3879en.pdf|archive-date=July 11, 2019}}</ref>
|-
! style="background:#fffdd0;"| Rank
! style="background:#fffdd0;"| Country
! style="background:#fffdd0;"| Production<br />([[metric ton]]s)
|-
| 1
| {{IND}}
| style="text-align:right" | {{formatnum:186143000}}
|-
| –
| ''{{EU}}''
| style="text-align:right" | ''{{formatnum:167256000}}''
|-
| 2
| {{US}}
| style="text-align:right" | {{formatnum:98646000}}
|-
| 3
| {{PAK}}
| style="text-align:right" | {{formatnum:45623000}}
|-
| 4
| {{BRA}}
| style="text-align:right" | {{formatnum:35539000}}
|-
| 5
| {{CHN}}
| style="text-align:right" | {{formatnum:31592000}}
|-
| 6
| {{RUS}}
| style="text-align:right" | {{formatnum:31527000}}
|-
| 7
| {{TUR}}
| style="text-align:right" | {{formatnum:22791000}}
|-
| 8
| {{NZ}}
| style="text-align:right" | {{formatnum:21372000}}
|- 
| colspan="2"; style="text-align:center" | '''World'''
| style="text-align:right" | '''{{formatnum:842989000}}'''
|}
{{stack end}}

{{stack begin | float=left}}
{|class="wikitable sortable"
|+ Top ten cow milk producers<br />in 2020<ref>{{cite web |url=http://faostat.fao.org/site/339/default.aspx |title=Milk, whole fresh cow producers |publisher=[[FAO|UN Food & Agriculture Organization]] |access-date=April 22, 2016 |url-status=dead |archive-url=https://web.archive.org/web/20110713020710/http://faostat.fao.org/site/339/default.aspx |archive-date=July 13, 2011}}</ref>
|-
! style="background:lightblue;"| Rank
! style="background:lightblue;"| Country
! style="background:lightblue;"| Production<br />([[metric ton]]s)
|-
| 1
| {{USA}}
| style="text-align:right" | {{formatnum:101251009}}
|-
| 2
| {{IND}}
| style="text-align:right" | {{formatnum:87822387}}
|-
| 3
| {{BRA}}
| style="text-align:right" | {{formatnum:36508411}}
|-
| 4
| {{CHN}}
| style="text-align:right" | {{formatnum:34400000}}
|-
| 5
| {{DEU}}
| style="text-align:right" | {{formatnum:33164910}}
|-
| 6
| {{RUS}}
| style="text-align:right" | {{formatnum:31959801}}
|-
| 7
| {{FRA}}
| style="text-align:right" | {{formatnum:25147310}}
|-
| 8
| {{PAK}}
| style="text-align:right" | {{formatnum:22508000}}
|-
| 9
| {{NZL}}
| style="text-align:right" | {{formatnum:21871305}}
|-
| 10
| {{TUR}}
| style="text-align:right" | {{formatnum:20000000}}
|}
{{stack end}}
{{stack begin | float=left}}
{|class="wikitable sortable"
|+ Top ten sheep milk producers<br />in 2020<ref>{{cite web |url=http://faostat.fao.org/site/339/default.aspx |title=Milk, whole fresh sheep producers |publisher=[[FAO|UN Food & Agriculture Organization]] |access-date=April 22, 2016 |url-status=dead |archive-url=https://web.archive.org/web/20110713020710/http://faostat.fao.org/site/339/default.aspx |archive-date=July 13, 2011}}</ref>
|-
! style="background:lightgreen;"| Rank
! style="background:lightgreen;"| Country
! style="background:lightgreen;"| Production<br />(metric tons)
|-
| 1
| {{CHN}}
| style="text-align:right" | {{formatnum:1211831}}
|-
| 2
| {{TUR}}
| style="text-align:right" | {{formatnum:1207427}}
|-
| 3
| {{GRC}}
| style="text-align:right" | {{formatnum:945430}}
|-
| 4
| {{SYR}}
| style="text-align:right" | {{formatnum:705582}}
|-
| 5
| {{DZA}}
| style="text-align:right" | {{formatnum:592293}}
|-
| 6
| {{ESP}}
| style="text-align:right" | {{formatnum:556250}}
|-
| 7
| {{ITA}}
| style="text-align:right" | {{formatnum:481970}}
|-
| 8
| {{ROU}}
| style="text-align:right" | {{formatnum:426000}}
|-
| 9
| {{SDN}}
| style="text-align:right" | {{formatnum:416002}}
|-
| 10
| {{SOM}}
| style="text-align:right" | {{formatnum:406541}}
|}
{{stack end}}
{{stack begin | float=left}}
{|class="wikitable sortable"
|+ Top ten goat milk producers<br />in 2020<ref>{{cite web |url=http://faostat.fao.org/site/339/default.aspx |title=Milk, whole fresh goat producers |publisher=[[FAO|UN Food & Agriculture Organization]] |access-date=April 22, 2016 |url-status=dead |archive-url=https://web.archive.org/web/20110713020710/http://faostat.fao.org/site/339/default.aspx |archive-date=July 13, 2011}}</ref>
|-
! style="background:lightpink;"| Rank
! style="background:lightpink;"| Country
! style="background:lightpink;"| Production<br />(metric tons)
|-
| 1
| {{IND}}
| style="text-align:right" | {{formatnum:5888077}}
|-
| 2
| {{BGD}}
| style="text-align:right" | {{formatnum:2671911}}
|-
| 3
| {{SDN}}
| style="text-align:right" | {{formatnum:1165043}}
|-
| 4
| {{PAK}}
| style="text-align:right" | {{formatnum:965000}}
|-
| 5
| {{FRA}}
| style="text-align:right" | {{formatnum:679300}}
|-
| 6
| {{TUR}}
| style="text-align:right" | {{formatnum:554143}}
|-
| 7
| {{ESP}}
| style="text-align:right" | {{formatnum:523900}}
|-
| 8
| {{SSD}}
| style="text-align:right" | {{formatnum:467148}}
|-
| 9
| {{NER}}
| style="text-align:right" | {{formatnum:407346}}
|-
| 10
| {{NLD}}
| style="text-align:right" | {{formatnum:407000}}
|}
{{stack end}}
{{stack begin | float=left}}
{|class="wikitable sortable"
|+ Top ten buffalo milk producers<br />in 2020<ref>{{cite web |url=http://faostat.fao.org/site/339/default.aspx |title=Milk, whole fresh buffalo producers |publisher=[[FAO|UN Food & Agriculture Organization]] |access-date=April 22, 2016 |url-status=dead |archive-url=https://web.archive.org/web/20110713020710/http://faostat.fao.org/site/339/default.aspx |archive-date=July 13, 2011}}</ref>
|-
! style="background:lightgrey;"| Rank
! style="background:lightgrey;"| Country
! style="background:lightgrey;"| Production<br />(metric tons)
|-
| 1
| {{IND}}
| style="text-align:right" | {{formatnum:90026273}}
|-
| 2
| {{PAK}}
| style="text-align:right" | {{formatnum:37256000}}
|-
| 3
| {{CHN}}
| style="text-align:right" | {{formatnum:2919966}}
|-
| 4
| {{EGY}}
| style="text-align:right" | {{formatnum:1747641}}
|-
| 5
| {{NPL}}
| style="text-align:right" | {{formatnum:1380600}}
|-
| 6
| {{ITA}}
| style="text-align:right" | {{formatnum:253830}}
|-
| 7
| {{MMR}}
| style="text-align:right" | {{formatnum:205102}}
|-
| 8
| {{IRN}}
| style="text-align:right" | {{formatnum:128000}}
|-
| 9
| {{MNG}}
| style="text-align:right" | {{formatnum:104645}}
|-
| 10
| {{IDN}}
| style="text-align:right" | {{formatnum:89983}}
|}
{{stack end}}
{{Clear}}

In 2012, the largest producer of milk and milk products was India, followed by the United States of America, China, Pakistan and Brazil.<ref>{{cite web |title=Dairy production and products: Milk production |url=http://www.fao.org/agriculture/dairy-gateway/milk-production/en/ |publisher=Food and Agriculture Organization |access-date=December 3, 2015 |archive-url=https://web.archive.org/web/20151208213729/http://www.fao.org/agriculture/dairy-gateway/milk-production/en/ |archive-date=December 8, 2015 |url-status=live}}</ref> All 28 European Union members together produced {{convert|153.8|e6tonne|e6ST|abbr=off}} of milk in 2013, the largest by any [[Political union|politico]]-[[Economic union|economic]] union.<ref>{{cite web |title=Milk and milk product statistics{{nbsp}}– Statistics Explained |url=http://ec.europa.eu/eurostat/statistics-explained/index.php/Milk_and_milk_product_statistics#Milk_production |publisher=European Commission |access-date=December 3, 2015 |archive-url=https://web.archive.org/web/20151128075312/http://ec.europa.eu/eurostat/statistics-explained/index.php/Milk_and_milk_product_statistics#Milk_production |archive-date=November 28, 2015 |url-status=live }}</ref>

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 corporation|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.<ref>Henriksen, J. (2009) [https://web.archive.org/web/20170525161438/ftp://ftp.fao.org/docrep/fao/011/i0521e/i0521e00.pdf "Milk for Health and Wealth".] FAO Diversification Booklet Series 6, Rome</ref> 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.<ref>Sinha, O.P. (2007) [http://www.fao.org/docrep/016/ap299e/ap299e.pdf Agro-industries characterization and appraisal: Dairy in India] {{Webarchive|url=https://web.archive.org/web/20121113195345/http://www.fao.org/docrep/016/ap299e/ap299e.pdf |date=November 13, 2012 }}, FAO, Rome</ref>

===Production yields===
FAO reports<ref name=gs12/> Israel dairy farms are the most productive in the world, with a yield of {{convert|12,546|kg|lbs}} milk per cow per year. This survey over 2001 and 2007 was conducted by ICAR (International Committee for Animal Recording)<ref>{{cite web |url=http://www.icar.org/ |title=International Committee for Animal Recording |publisher=ICAR – icar.org |access-date=August 1, 2012 |archive-url=https://web.archive.org/web/20120731024430/http://www.icar.org/ |archive-date=July 31, 2012 |url-status=live}}</ref> 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 {{convert|7,726| to|8,550|kg|abbr=on}} per cow in these developed countries. The lowest average production was in New Zealand at {{convert|3,974|kg|lb|abbr=on}} 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 was {{convert|9,954|kg|lb|abbr=on}} per year in 2010. In contrast, the milk yields per cow in India and China{{nbsp}}– the second and third largest producers{{nbsp}}– were respectively {{convert|1,154|kg|lb|abbr=on}} and {{convert|2,282|kg|lb|abbr=on}} per year.<ref>[http://faostat.fao.org/site/569/DesktopDefault.aspx?PageID=569#ancor FAOSTAT, Yield data 2010{{nbsp}}– Cow milk, whole, fresh] {{Webarchive|url=https://web.archive.org/web/20120213172341/http://faostat.fao.org/site/569/DesktopDefault.aspx?PageID=569#ancor |date=February 13, 2012 }}, FAOSTAT, Food And Agricultural Organization of the United Nations; faostat.fao.org. Retrieved August 1, 2012.</ref>
[[File:World Emissions Intensity Of Agricultural Commodities (2021).svg|thumb|Sheep and cow milk have the third and fourth highest emissions intensity of any agricultural commodity.]]

The [[IPCC Sixth Assessment Report]] mentions the possibility that the already recorded stagnation of dairy production in both China and [[West Africa]] can be attributed to persistent increases in [[heat stress]] caused by [[climate change]].<ref name="AR6_WGII_Chapter5">Kerr R.B., Hasegawa T., Lasco R., Bhatt I., Deryng D., Farrell A., Gurney-Smith H., Ju H., Lluch-Cota S., Meza F., Nelson G., Neufeldt H., Thornton P., 2022: [https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter05.pdf Chapter 5: Food, Fibre and Other Ecosystem Products] {{Webarchive|url=https://web.archive.org/web/20230514001636/https://www.ipcc.ch/report/ar6/wg2/downloads/report/IPCC_AR6_WGII_Chapter05.pdf |date=May 14, 2023 }}. In [https://www.ipcc.ch/report/ar6/wg2/ Climate Change 2022: Impacts, Adaptation and Vulnerability] {{Webarchive|url=https://web.archive.org/web/20220228114918/https://www.ipcc.ch/report/ar6/wg2/ |date=February 28, 2022 }} [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, US, pp. 1457–1579 |doi=10.1017/9781009325844.012</ref>{{rp|747}} This is a plausible [[hypothesis]], because even ''mild'' heat stress can reduce daily yields: research in Sweden found that average daily temperatures of {{convert|20-25|C}} reduce daily milk yield per cow by 0.2&nbsp;kg, with the loss reaching 0.54&nbsp;kg for {{convert|25-30|C}}.<ref>{{cite journal |last1=Ahmed |first1=Haseeb |last2=Tamminen |first2=Lena-Mari |last3=Emanuelson |first3=Ulf |date=22 November 2022 |title=Temperature, productivity, and heat tolerance: Evidence from Swedish dairy production |journal=Climatic Change |language=en |volume=175 |issue=1–2 |pages=1269–1285 |doi=10.1007/s10584-022-03461-5 |bibcode=2022ClCh..175...10A |s2cid=253764271|doi-access=free }}</ref> Research in a humid tropical climate describes a more linear relationship, with every unit of heat stress reducing yield by 2.13%.<ref>{{cite journal |last1=Pramod |first1=S. |last2=Sahib |first2=Lasna |last3=Becha B |first3=Bibin |last4=Venkatachalapathy |first4=R. Thirupathy |date=3 January 2021 |title=Analysis of the effects of thermal stress on milk production in a humid tropical climate using linear and non-linear models |url=https://link.springer.com/article/10.1007/s11250-020-02525-x |journal=Tropical Animal Health and Production |language=en |volume=53 |issue=1 |pages=1269–1285 |doi=10.1007/s11250-020-02525-x |pmid=33392887 |s2cid=255113614 |access-date=October 13, 2023 |archive-date=November 6, 2023 |archive-url=https://web.archive.org/web/20231106111323/https://link.springer.com/article/10.1007/s11250-020-02525-x |url-status=live |url-access=subscription }}</ref> In the [[intensive farming]] systems, daily milk yield per cow declines by 1.8&nbsp;kg during severe heat stress. In [[organic farming]] systems, the effect of heat stress on milk yields is limited, but milk ''quality'' suffers substantially, with lower fat and [[protein]] content.<ref>{{cite journal |last1=Blanco-Penedo |first1=Isabel |last2=Velarde |first2=Antonio |last3=Kipling |first3=Richard P. |last4=Ruete |first4=Alejandro |date=25 August 2020 |title=Modeling heat stress under organic dairy farming conditions in warm temperate climates within the Mediterranean basin |journal=Climatic Change |language=en |volume=162 |issue=3 |pages=1269–1285 |doi=10.1007/s10584-020-02818-y |bibcode=2020ClCh..162.1269B |s2cid=221283658|doi-access=free |hdl=20.500.12327/909 |hdl-access=free }}</ref> In China, daily milk production per cow is already lower than the average by between 0.7 and 4&nbsp;kg in July (the hottest month of the year), and by 2070, it may decline by up to 50% (or 7.2&nbsp;kg) due to climate change.<ref>{{cite journal |last1=Ranjitkar |first1=Sailesh |last2=Bu |first2=Dengpan |last3=Van Wijk |first3=Mark |last4=Ma |first4=Ying |last5=Ma |first5=Lu |last6=Zhao |first6=Lianshen |last7=Shi |first7=Jianmin |last8=Liu |first8=Chousheng |last9=Xu |first9=Jianchu |date=2 April 2020 |title=Will heat stress take its toll on milk production in China? |url=https://link.springer.com/article/10.1007/s10584-020-02688-4 |journal=Climatic Change |language=en |volume=161 |issue=4 |pages=637–652 |doi=10.1007/s10584-020-02688-4 |bibcode=2020ClCh..161..637R |s2cid=214783104 |access-date=October 13, 2023 |archive-date=October 29, 2023 |archive-url=https://web.archive.org/web/20231029201854/https://link.springer.com/article/10.1007/s10584-020-02688-4 |url-status=live }}</ref> Heatwaves can also reduce milk yield, with particularly acute impacts if the heatwave lasts for four or more days, as at that point the cow's thermoregulation capacity is usually exhausted, and its core body temperature starts to increase.<ref>{{cite journal |last1=Manica |first1=Emanuel |last2=Coltri |first2=Priscila Pereira |last3=Pacheco |first3=Verônica Madeira |last4=Martello |first4=Luciane Silva |date=6 October 2022 |title=Changes in the pattern of heat waves and the impacts on Holstein cows in a subtropical region |url=https://link.springer.com/article/10.1007/s00484-022-02374-3 |journal=International Journal of Biometeorology |language=en |volume=66 |issue=12 |pages=2477–2488 |doi=10.1007/s00484-022-02374-3 |pmid=36201039 |bibcode=2022IJBm...66.2477M |s2cid=252736195 |access-date=October 13, 2023 |archive-date=November 8, 2023 |archive-url=https://web.archive.org/web/20231108055649/https://link.springer.com/article/10.1007/s00484-022-02374-3 |url-status=live |url-access=subscription }}</ref>

===Price===
[[File:Milk Prices.webp|thumb|300px|Milk price per gallon of whole milk]]
[[File:Corn vs Ethanol production.webp|thumb|300px|Corn vs ethanol production in the United States
{{legend|#FFD932|Total corn production ([[bushel]]s) (left)}}
{{legend|B51700|Corn used for ethanol fuel (bushels) (left)}}
{{legend-line|#313131 solid 3px|Percent of corn used for ethanol (right)}}
]]
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.<ref>Wayne Arnold, "A Thirst for Milk Bred by New Wealth Sends Prices Soaring", [[The New York Times]] September 4, 2007.</ref> In 2010 the [[United States Department of Agriculture|Department of Agriculture]] predicted farmers would receive an average of {{convert|1.35|$/USgal|$/l $/impgal|lk=in}} of cow's milk, which is down {{convert|30|¢/USgal|¢/l ¢/impgal}} from 2007 and below the [[break-even]] point for many cattle farmers.<ref>{{cite news |first=Elizabeth |last=Bewley |title=Dairy farmers tackle big coops |newspaper=Burlington Free Press |location=Burlington, VT |pages=8B |date=June 24, 2010}}</ref>

== {{Anchor|Physical and chemical properties}}Composition ==
[[File:TriglycerideDairyButter.png|thumb|Butterfat is a [[triglyceride]] (fat) formed from fatty acids such as [[myristic acid|myristic]], [[palmitic acid|palmitic]], and [[oleic acid]]s.]]
Milk is an [[emulsion]] or [[colloid]] of [[butterfat]] [[globules of fat|globules]] within a water-based fluid that contains dissolved [[carbohydrate]]s and protein aggregates with minerals.<ref>Rolf Jost "Milk and Dairy Products" Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2002. {{doi|10.1002/14356007.a16_589.pub3}}</ref> 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.<ref name="Fox-1995-v3">Fox, P.F. Advanced Dairy Chemistry, Vol. 3: Lactose, Water, Salts and Vitamins. 2nd ed. Chapman and Hall: New York, 1995.</ref>

===pH===
The [[pH]] of cow's milk, ranging from 6.7 to 6.9, is similar to other [[bovines]] and non-bovine [[mammals]].<ref>{{Cite journal |last1=Elbagerma |first1=Mohamed A. |last2=Alajital |first2=A. I. |last3=Edwards |first3=H. G. M. |date=September 2014 |title=A Comparative Study on the Physicochemical Parameters and Trace Elements in Raw Milk Samples Collected from Misurata- Libya |url=https://www.researchgate.net/publication/266616267 |journal=SOP Transactions on Analytical Chemistry |volume=1 |issue=2 |pages=15–23 |doi=10.15764/ACHE.2014.02002 |doi-broken-date=November 1, 2024 |s2cid=138302219 |via=ResearchGate}}</ref>

===Lipids===
{{Main|Butterfat}}
Full fat milk contains about 33 grams of fat per liter, including about 19 grams of saturated fat, 1.2 grams of omega 6 fatty acids, and 0.75 grams of omega 3 fatty acids per liter. The amount of fat varies for products where (some of) the fat has been removed, such as in skimmed milk.<ref>{{Cite journal |last1=Haug |first1=Anna |last2=Høstmark |first2=Arne T. |last3=Harstad |first3=Odd M. |date=2007-09-25 |title=Bovine milk in human nutrition – a review |journal=Lipids in Health and Disease |language=en |volume=6 |issue=1 |pages=25 |doi=10.1186/1476-511X-6-25 |doi-access=free |issn=1476-511X |pmc=2039733 |pmid=17894873}}</ref>

Initially milk fat is secreted in the form of a fat globule surrounded by a [[Milk fat globule membrane|membrane]].<ref name="Fox-1995-v2">Fox, P.F. Advanced Dairy Chemistry: Vol 2 Lipids. 2nd Ed. Chapman and Hall: New York, 1995.</ref> Each fat globule is composed almost entirely of triacylglycerols and is surrounded by a membrane consisting of complex lipids such as [[phospholipid]]s, along with proteins. These act as [[emulsifier]]s which keep the individual globules from coalescing and protect the contents of these globules from various [[enzyme]]s 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 due to genetic, lactational, and nutritional factor difference between different species.<ref name="Fox-1995-v2" />

Fat globules vary in size from less than 0.2 to about 15 [[micrometre|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.<ref name="Fox-1995-v2"/> The [[fat-soluble]] vitamins [[vitamin A|A]], [[vitamin D|D]], [[vitamin E|E]], and [[vitamin K|K]] along with essential fatty acids such as linoleic and linolenic acid are found within the milk fat portion of the milk.<ref name="On Food and Cooking"/>

{| class="sortable wikitable" style="margin:auto"
|+Main milk fatty acids, length, share of total<ref name="LubaryHofland2010">{{cite journal |last1=Lubary |first1=Marta |last2=Hofland |first2=Gerard W. |last3=ter Horst |first3=Joop H. |title=The potential of milk fat for the synthesis of valuable derivatives |journal=European Food Research and Technology |volume=232 |issue=1 |year=2010 |pages=1–8 |issn=1438-2377 |doi=10.1007/s00217-010-1387-3 |s2cid=85373338|doi-access=free}}</ref>
|-
! Fatty acid !! length !! mol% (rounded) 
|-
| Butyryl || C4 ||  12 
|-
| Myristyl || C14 || 11 
|-
| Palmityl || C16 || 24 
|-
| Oleyl || C18:1 || 24 
|}

===Proteins===
Normal bovine milk contains 30–35&nbsp;grams 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====
{{Main|Casein}}
The largest structures in the fluid portion of the milk are [[casein|"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. 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 [[colloid]]al [[suspension (chemistry)|suspension]] in the water-based surrounding fluid.<ref name="On Food and Cooking"/><ref name="chem">{{cite web |last=Goff |first=Douglas |url=https://www.uoguelph.ca/foodscience/book-page/raw-milk-quality |title=Raw milk quality |work=Dairy Science and Technology |publisher=University of Guelph Food Science, Guelph, Ontario, Canada |access-date=February 8, 2011 |year=2010 |archive-url=https://web.archive.org/web/20141231022516/http://www.uoguelph.ca/foodscience/book-page/raw-milk-quality |archive-date=December 31, 2014 |url-status=live}}</ref>

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''. [[Lactoglobulin]] is the most common whey protein by a large margin.<ref name="On Food and Cooking"/> The ratio of caseins to whey proteins varies greatly between species; for example, it is 82:18 in cows and around 32:68 in humans.<ref name=Applications2017>{{cite book |title=Handbook of Milk of Non-Bovine Mammals |chapter=Potential Applications of Non-Bovine Mammalian Milk in Infant Nutrition |editor1-first=Young W. |editor1-last=Park |editor2-first=George F.W. |editor2-last=Haenlein |editor3-first=William L. |editor3-last=Wendorff |first1=Shane V. |last1=Crowley |first2=Alan L. |last2=Kelly |first3=John A. |last3=Lucey |first4=James A. |last4=O'Mahony |page=630 |date=2017 |publisher=John Wiley & Sons Ltd. |edition=2nd |doi=10.1002/9781119110316.ch13 |isbn=978-1-119-11031-6}}</ref>

{| class="sortable wikitable" style="margin:auto"
|+Ratio of caseins to whey proteins in milk of nine mammals<ref name=Applications2017/>
|-
! Species !! Ratio
|-
| Human || 29.7:70.3 – 33.7:66.3 
|-
| Bovine || 82:18
|-
| Caprine || 78:22
|-
| Ovine || 76:24
|-
| Buffalo || 82:18
|-
| Equine || 52:48 
|-
| Camel || 73:27 – 76:24
|-
| Yak || 82:18
|-
| Reindeer || 80:20 – 83:17
|}

===Salts, minerals, and vitamins===
Bovine milk contains a variety of cations and anions traditionally referred to as "minerals" or "milk salts". Calcium, phosphate, magnesium, sodium, potassium, citrate, and chloride are all included and they typically occur at concentrations of 5–40{{nbsp}}[[Molar concentration#Units|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.<ref name="Fox-1995-v3"/> In addition to calcium, milk is a source of many vitamins: Vitamins A, B1, B2, B5 B6, B7, B12, and D.

====Calcium phosphate structure====
For many years the most widely 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 micellar structure. Specifically in this view unstructured proteins organize around the calcium phosphate, giving rise to their structure, and thus no specific structure is formed.

Under 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 Ca<sub>9</sub>(PO<sub>4</sub>)<sub>6</sub>;
whereas others say it is similar to the structure of the mineral [[brushite]], CaHPO<sub>4</sub>·2H<sub>2</sub>O.<ref>[http://www.foodsci.uoguelph.ca/dairyedu/chem.html chemistry and physics] {{Webarchive|url=https://web.archive.org/web/20060614214133/http://www.foodsci.uoguelph.ca/dairyedu/chem.html |date=June 14, 2006 }}. Foodsci.uoguelph.ca. Retrieved December 9, 2011.</ref>

===Sugars and carbohydrates===
[[File:Hydrolysis of lactose.svg|thumb|A simplified representation of a [[lactose]] molecule being broken down into [[glucose]] (2) and [[galactose]] (1)]]
Milk contains several different [[carbohydrate]]s, including [[lactose]], [[glucose]], [[galactose]], and other [[oligosaccharide]]s. The lactose gives milk its sweet taste and contributes approximately 40% of the calories in whole cow's milk's. Lactose is a disaccharide composite of two [[Monosaccharide|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.<ref name="Fox-1995-v3"/>

===Miscellaneous contents===
Other components found in raw cow's milk are living [[white blood cell]]s, mammary gland cells, various bacteria, vitamin C, and a large number of active enzymes.<ref name="On Food and Cooking"/>

===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.<ref name="On Food and Cooking"/> 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.<ref name="chem"/>

==Processing==
[[File:Milkproducts v2.svg|thumb|Milk products and productions relationships (click to enlarge)]]
In most Western countries, centralized dairy facilities process milk and [[dairy product|products obtained from milk]], such as cream, butter, and cheese. In the US, these dairies usually are local companies, while in the [[Southern Hemisphere]] facilities may be run by large multi-national corporations such as [[Fonterra]].

===Pasteurization===
{{Main|Pasteurization#Milk}}

Pasteurization is used to kill harmful [[pathogenic bacteria]] such as ''[[M. paratuberculosis]]'' and ''[[E. coli 0157:H7]]'' by heating the milk for a short time and then immediately cooling it.<ref name="holzinger97">{{cite journal |doi=10.20506/rst.16.2.1037 |title=Milk pasteurisation and safety: A brief history and update |year=1997 |url=https://www.oie.int/doc/ged/d9152.pdf |last1=Holsinger |first1=V.H. |last2=Rajkowski |first2=K.T. |last3=Stabel |first3=J.R. |journal=Revue Scientifique et Technique de l'OIE |volume=16 |issue=2 |pages=441–451 |pmid=9501358 |access-date=January 20, 2021 |archive-date=January 28, 2021 |archive-url=https://web.archive.org/web/20210128060632/https://www.oie.int/doc/ged/d9152.pdf |url-status=live }}</ref> Types of pasteurized milk include full cream, reduced fat, skim milk, calcium enriched, flavored, and UHT.<ref>{{Cite news |url=https://www.betterhealth.vic.gov.au/health/healthyliving/milk |title=Milk |last=Services |first=Department of Health & Human |access-date=October 9, 2016 |archive-url=https://web.archive.org/web/20161010213031/https://www.betterhealth.vic.gov.au/health/healthyliving/milk |archive-date=October 10, 2016 |url-status=live}}</ref> The standard high temperature short time (HTST) process of {{convert|72|°C}} for 15 seconds completely kills pathogenic bacteria in milk,<ref>{{cite journal |doi=10.1021/ie50397a017 |title=Short-Time Pasteurization of Milk |journal=Industrial & Engineering Chemistry |volume=35 |issue=1 |pages=71–84 |year=1943 |last1=Ball |first1=C. Olin}}</ref> rendering it safe to drink for up to three weeks if continually refrigerated.<ref>{{cite journal |doi=10.3168/jds.2009-2144 |pmid=19762797 |title=High temperature, short time pasteurization temperatures inversely affect bacterial numbers during refrigerated storage of pasteurized fluid milk |journal=Journal of Dairy Science |volume=92 |issue=10 |pages=4823–32 |year=2009 |last1=Ranieri |first1=M.L |last2=Huck |first2=J.R |last3=Sonnen |first3=M |last4=Barbano |first4=D.M |last5=Boor |first5=K.J |doi-access=free}}</ref> 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% or greater (even to complete loss).<ref>{{Cite journal |last=Wilson |first=G.S. |title=The Pasteurization of Milk |journal=British Medical Journal |volume=1 |issue=4286 |year=1943 |pages=261–62 |pmc=2282302 |pmid=20784713 |doi=10.1136/bmj.1.4286.261}}</ref> 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 in a well-balanced diet, 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<ref>{{cite book |title=Handbook of Food and Beverage Fermentation Technology |date=2004 |isbn=978-0-203-91355-0 |page=265 |url=https://books.google.com/books?id=PC_O7u1NPZEC&q=Handbook+of+Food+and+Beverage+Fermentation+Technology&pg=PP9 |access-date=September 6, 2016 |last1=Hui |first1=Y.H. |last2=Meunier-Goddik |first2=Lisbeth |last3=Josephsen |first3=Jytte |last4=Nip |first4=Wai-Kit |last5=Stanfield |first5=Peggy S |publisher=CRC Press |archive-date=August 1, 2020 |archive-url=https://web.archive.org/web/20200801132150/https://books.google.com/books?id=PC_O7u1NPZEC |url-status=live }}</ref> (as compared to 99.999% killing of microorganisms in standard [[flash pasteurization|HTST pasteurization]]).<ref>{{cite journal |last1=Stabel |first1=J |last2=Lambertz |first2=A |title=Efficacy of Pasteurization Conditions for the Inactivation of Mycobacterium avium subsp. paratuberculosis in Milk |journal=Journal of Food Protection |date=April 27, 2004 |volume=67 |issue=12 |pages=2719–26 |url=http://naldc.nal.usda.gov/download/40448/PDF |access-date=September 6, 2016 |doi=10.4315/0362-028x-67.12.2719 |pmid=15633677 |archive-url=https://web.archive.org/web/20160920023340/http://naldc.nal.usda.gov/download/40448/PDF |archive-date=September 20, 2016 |url-status=live|doi-access=free }}</ref> 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.<ref name=Peterson2015 /> As with microfiltration, the fat may be removed before filtration and added back in afterwards.<ref name=ncse>{{Cite web |url=http://ncseonline.org/nle/crsreports/05jun/97-905.pdf |title=CRS Report for Congress: Agriculture: A Glossary of Terms, Programs, and Laws, 2005 Edition{{nbsp}}– Order Code 97-905 |access-date=July 26, 2009 |archive-url=https://web.archive.org/web/20110810044532/http://ncseonline.org/nle/crsreports/05jun/97-905.pdf |archive-date=August 10, 2011 |url-status=dead }}</ref> [[Ultrafiltered milk]] is used in 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.<ref>{{cite news |last1=Eaves |first1=Ali |title=Is This the Best New Post-Workout Drink? |url=https://www.menshealth.com/nutrition/a19540806/is-filtered-milk-better-for-you/|access-date=March 29, 2018 |work=Men's Health |date=August 24, 2015|archive-url=https://web.archive.org/web/20180330013005/https://www.menshealth.com/nutrition/a19540806/is-filtered-milk-better-for-you/|archive-date=March 30, 2018|url-status=live}}</ref>

===Creaming and homogenization===
[[File:Cow milking machine in action DSC04132.jpg|thumb|A milking machine in action]]
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 [[centrifuge|centrifugal]] [[cream separator]]s. The fat globules rise to the top of a container of milk because fat is less dense than water.<ref name="On Food and Cooking"/>

The smaller the globules, the more other molecular-level forces prevent this from happening. 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.<ref name="On Food and Cooking"/> 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.<ref name="On Food and Cooking"/>

Milk often is [[Homogenization (chemistry)|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]].<ref>{{cite web |last=Goff |first=Douglas |title=Homogenization of Milk and Milk Products |url=http://www.foodsci.uoguelph.ca/dairyedu/homogenization.html |work=Dairy Science and Technology |publisher=University of Guelph |access-date=February 8, 2011 |year=2010 |archive-url=https://web.archive.org/web/20110524061747/http://www.foodsci.uoguelph.ca/dairyedu/homogenization.html |archive-date=May 24, 2011 |url-status=dead}}</ref> 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 [[rancidification|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.<ref name="On Food and Cooking"/> 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.<ref>{{cite web |url=https://www.sciencedaily.com/releases/2002/12/021223084204.htm |title=Research Can Lead To Longer Shelf Life For Dairy Products |publisher=Sciencedaily.com |date=December 23, 2002 |access-date=August 28, 2010 |archive-url=https://web.archive.org/web/20100819113427/http://www.sciencedaily.com/releases/2002/12/021223084204.htm |archive-date=August 19, 2010 |url-status=live}}</ref><!--Homogenized milk may be more digestible than unhomogenized milk.<ref name="MichalskiJanuel">{{cite journal |title=Does homogenization affect the human health properties of cow's milk? |doi=10.1016/j.tifs.2006.02.004 |year=2006 |last1=Michalski |first1=Marie-Caroline |last2=Januel |first2=Caroline |journal=Trends in Food Science & Technology |volume=17 |issue=8 |pages=423–37}}</ref>

Kurt A. Oster, M.D., who worked during the 1960s through the 1980s, suggested a link between homogenized milk and [[atherosclerosis]], due to damage to [[plasmalogen]] resulting from the release of bovine [[xanthine oxidase]] (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 atherosclerosis and milk consumption.<ref name="MichalskiJanuel"/>-->

=== UHT ===
[[Ultra-high-temperature processing|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 six months, as long as the package is not opened. Milk is firstly homogenized and then is heated to {{Convert|138|C|F}} for 2–4{{nbsp}}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 pasteurized. The treated milk will keep for up to 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. However, 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.<ref>{{Cite news |url=https://www.scientificamerican.com/article/experts-organic-milk-lasts-longer/ |title=Why does organic milk last so much longer than regular milk? |newspaper=Scientific American |access-date=December 1, 2016 |archive-url=https://web.archive.org/web/20161201213111/https://www.scientificamerican.com/article/experts-organic-milk-lasts-longer/ |archive-date=December 1, 2016 |url-status=live}}</ref>

==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.<ref name="intro"/> For example:
* [[breast milk|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% [[Dietary mineral|minerals]]<ref>{{Cite news |url=http://www.hindu.com/seta/2008/07/10/stories/2008071050201800.htm |title=Milk contains traces of ash |date=July 10, 2008 |access-date=August 28, 2010 |location=Chennai, India |archive-url=https://web.archive.org/web/20120118000721/http://www.hindu.com/seta/2008/07/10/stories/2008071050201800.htm |archive-date=January 18, 2012 |work=[[The Hindu]] |url-status=dead}}</ref> and supplies 66&nbsp;kcal of energy per 100&nbsp;grams. See also [[#Nutritional value|Nutritional value]] further on in this article and more complete lists at online sources that list values and differences in categories.<ref>''[https://nutritiondata.self.com/facts/dairy-and-egg-products/69/2 Milk, Whole, 3.25% milkfat] {{Webarchive|url=https://web.archive.org/web/20240129200356/https://www.self.com/ |date=January 29, 2024 }}'', Self Nutrition Data, accessed April 30, 2022</ref>

Donkey and horse milk have the lowest fat content, while the milk of [[pinniped|seals]] and whales may contain more than 50% fat.<ref>{{cite encyclopedia |title=Whale |url=http://encarta.msn.com/encyclopedia_761565254_3/Whale.html |encyclopedia=Encarta |url-status=dead |archive-url=https://web.archive.org/web/20091028232724/http://encarta.msn.com/encyclopedia_761565254_3/Whale.html |archive-date=October 28, 2009}}</ref>

{| class="wikitable"
|+ Milk composition analysis, per 100&nbsp;grams
! Constituents
! Unit
! Cow
! Goat
! Sheep
! [[Water buffalo|Water<br />buffalo]]
|-
| 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
|-
| ----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

|-
| Carbohydrate (i.e. the sugar form of [[lactose]])
| g
| 4.8
| 4.4
| 5.1
| 4.9
|-
| Cholesterol
| mg
| 14
| 10
| 11
| 8
|-
| Calcium
| mg
| 120
| 100
| 170
| 195
|-
|rowspan="2"| Energy
| kcal
| 66
| 60
| 95
| 110
|-
| kJ
| 275
| 253
| 396
| 463
|}

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

{| class="wikitable"
|+Milk fat percentages
!Cow breed
!Approximate percentage
|-
|[[Jersey cattle|Jersey]]
|5.2
|-
|[[Zebu]]
|4.7
|-
|[[Brown Swiss]]
|4.0
|-
|[[Holstein cattle|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%.<ref name="On Food and Cooking"/>

Milk fat percentages may be manipulated by dairy farmers' stock diet formulation strategies. The infection known as [[mastitis]], [[Mastitis in dairy cattle|especially in dairy cattle]], can cause fat levels to decline.<ref>{{Cite book |url=https://archive.org/details/designingfoodsan00nati |url-access=registration |page=[https://archive.org/details/designingfoodsan00nati/page/226 226] |title=Designing Foods: Animal Product Options in the Marketplace |publisher=National Academies Press |year=1988 |isbn=978-0-309-03795-2}}</ref>

===Nutritional value===
Processed cow's milk was formulated to contain differing amounts of fat during the 1950s. One cup (250&nbsp;mL) of 2%-fat cow's milk contains 285&nbsp;mg of [[calcium]], which represents 22% to 29% of the [[daily recommended intake]] (DRI) of calcium for an adult. Depending on its age, milk contains 8&nbsp;grams of [[protein]], and a number of other nutrients{{Which|date=July 2022}} (either naturally or through [[food fortification|fortification]]).

Whole milk has a [[glycemic index]] of 39±3.<ref name=International-Tables-2008>{{cite journal |last1=Atkinson |first1=Fiona S. |date=1 December 2008 |url=https://diabetesjournals.org/care/article/31/12/2281/24911/International-Tables-of-Glycemic-Index-and |title=International Tables of Glycemic Index and Glycemic Load Values: 2008 |journal=Diabetes Care |volume=31 |issue=12 |pages=2281–2283 |doi=10.2337/dc08-1239 |pmc=2584181 |pmid=18835944 |access-date=September 28, 2023 |archive-date=January 29, 2024 |archive-url=https://web.archive.org/web/20240129200317/https://diabetesjournals.org/care/article/31/12/2281/24911/International-Tables-of-Glycemic-Index-and |url-status=live }}</ref> A food is considered to have a low GI if it is 55 or less.

For [[protein quality]], whole milk has a [[Digestible Indispensable Amino Acid Score]] (DIAAS) of 1.43, with the [[limiting amino acid]] for those groups being [[methionine]] and [[cysteine]].<ref>{{cite Q |1=Q33645656 |doi-access=free}}</ref> A DIAAS of 1 or more is considered to be an excellent/high [[protein quality]] source.<ref>{{citation|title=Report of an FAO Expert Consultation, 31 March - 2 April 2011, Auckland, New Zealand|year=2013|publisher=[[Food and Agriculture Organization]]|isbn=978-92-5-107417-6|page=43}}</ref>

===Disease===
There is mixed evidence that drinking milk increases the risk of cancer in general, and good evidence that milk drinking may have a protective effect specifically against [[bowel cancer]].<ref name="k808">{{cite web | title=Can milk and dairy products cause cancer? | website=Cancer Research UK | date=1 November 2021 | url=https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/cancer-myths/can-milk-and-dairy-products-cause-cancer | access-date=3 August 2024}}</ref>

===Allergy===
{{Main|Milk allergy}}
One of the most common [[food allergy|food allergies]] in infants is to cow's milk. This is an immunologically mediated [[adverse reaction]], rarely fatal, to one or more cow's milk proteins.<ref>{{Cite journal |author=Høst A |title=Cow's milk protein allergy and intolerance in infancy. Some clinical, epidemiological and immunological aspects |journal=Pediatric Allergy and Immunology |volume=5 |issue=5 Suppl |pages=1–36 |year=1994 |pmid=7704117 |doi=10.1111/j.1399-3038.1994.tb00352.x |s2cid=26155994}}</ref> Milk allergy affects between 2% and 3% of babies and young children.<ref name="Savage2015">{{cite journal | vauthors = Savage J, Johns CB | title = Food allergy: epidemiology and natural history | journal = Immunology and Allergy Clinics of North America | volume = 35 | issue = 1 | pages = 45–59 | date = February 2015 | pmid = 25459576 | pmc = 4254585 | doi = 10.1016/j.iac.2014.09.004 }}</ref> To reduce risk, recommendations are that babies should be exclusively [[breastfed]] for at least four months, preferably six months, before introducing cow's milk.<ref>{{cite journal | vauthors = Vandenplas Y | title = Prevention and Management of Cow's Milk Allergy in Non-Exclusively Breastfed Infants | journal = Nutrients | volume = 9 | issue = 7 | pages = 731 | date = July 2017 | pmid = 28698533 | pmc = 5537845 | doi = 10.3390/nu9070731 | doi-access = free }}</ref> The majority of children outgrow milk allergy, but for about 0.4% the condition persists into adulthood.<ref name="Liu2010">{{cite journal | vauthors = Liu AH, Jaramillo R, Sicherer SH, Wood RA, Bock SA, Burks AW, Massing M, Cohn RD, Zeldin DC | title = National prevalence and risk factors for food allergy and relationship to asthma: results from the National Health and Nutrition Examination Survey 2005–2006 | journal = The Journal of Allergy and Clinical Immunology | volume = 126 | issue = 4 | pages = 798–806.e13 | date = October 2010 | pmid = 20920770 | pmc = 2990684 | doi = 10.1016/j.jaci.2010.07.026 }}</ref>

===Lactose intolerance===
{{Main|Lactose intolerance}}
Lactose intolerance is a condition in which people have symptoms due to deficiency or absence of the enzyme [[lactase]] in the [[small intestine]], causing poor absorption of milk lactose.<ref name=NIH2014Dig/><ref name=Deng2015>{{cite journal |vauthors=Deng Y, Misselwitz B, Dai N, Fox M |title=Lactose intolerance in adults: Biological mechanism and dietary management |journal=Nutrients |year=2015 |volume=7 |issue=9 |pages=8020–35 |pmid=26393648 |doi=10.3390/nu7095380 |pmc=4586575 |type=Review|doi-access=free}}</ref> People affected vary in the amount of lactose they can tolerate before symptoms develop,<ref name=NIH2014Dig/> which may include abdominal pain, [[bloating]], [[diarrhea]], gas, and [[nausea]].<ref name=NIH2014Dig/> Severity depends on the amount of milk consumed.<ref name=NIH2014Dig>{{cite web |title=Lactose intolerance |url=https://www.niddk.nih.gov/health-information/digestive-diseases/lactose-intolerance/definition-facts |publisher=National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health |access-date=January 28, 2021 |date=February 2018 |archive-date=February 8, 2021 |archive-url=https://web.archive.org/web/20210208150848/https://www.niddk.nih.gov/health-information/digestive-diseases/lactose-intolerance/definition-facts |url-status=live }}</ref> 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.<ref name=NIH2014Dig/><ref name=SuchyBrannon2010>{{cite journal |vauthors=Suchy FJ, Brannon PM, Carpenter TO, Fernandez JR, Gilsanz V, Gould JB, etal |title=NIH consensus development conference statement: Lactose intolerance and health. |journal=NIH Consens State Sci Statements |year=2010 |volume=27 |issue=2 |pages=1–27 |pmid=20186234 |url=https://consensus.nih.gov/2010/lactosestatement.htm |type=Consensus Development Conference, NIH. Review |access-date=December 6, 2016 |archive-url=https://web.archive.org/web/20161218125118/https://consensus.nih.gov/2010/lactosestatement.htm |archive-date=December 18, 2016 |url-status=dead}}</ref>

==Evolution of lactation==
{{main|Lactation}}
The [[mammary gland]] is thought to have derived from [[apocrine]] skin glands.<ref name="Oftedal 2002 225–252">{{cite journal |last=Oftedal |first=Olav T. |title=The mammary gland and its origin during synapsid evolution |journal=Journal of Mammary Gland Biology and Neoplasia |volume=7 |issue=3 |pages=225–52 |year=2002 |doi=10.1023/A:1022896515287 |pmid=12751889 |s2cid=25806501}}</ref> It has been suggested that the original function of lactation (milk production) was keeping eggs moist. Much of the argument is based on [[monotreme]]s (egg-laying mammals).<ref name="Oftedal 2002 225–252"/><ref>{{cite journal |last1=Oftedal |first1=Olav T. |title=The origin of lactation as a water source for parchment-shelled eggs |journal=Journal of Mammary Gland Biology and Neoplasia |volume=7 |issue=3 |pages=253–66 |year=2002 |pmid=12751890 |doi=10.1023/A:1022848632125 |s2cid=8319185}}</ref><ref>{{cite web |url=http://nationalzoo.si.edu/ConservationAndScience/SpotlightOnScience/oftedalolav20030714.cfm |archive-url=https://web.archive.org/web/20090414083919/http://nationalzoo.si.edu/ConservationAndScience/SpotlightOnScience/oftedalolav20030714.cfm |archive-date=April 14, 2009 |title=Lactating on Eggs |publisher=Nationalzoo.si.edu |date=July 14, 2003 |access-date=March 8, 2009}}</ref> The original adaptive significance of milk secretions may have been nutrition<ref>{{Cite journal |vauthors=Lefèvre CM, Sharp JA, Nicholas KR |title=Evolution of lactation: ancient origin and extreme adaptations of the lactation system |pmid=20565255 |journal=Annual Review of Genomics and Human Genetics |issue=1 |pages=219–38 |year=2010 |volume=11 |doi=10.1146/annurev-genom-082509-141806}}</ref> and immunological protection.<ref>{{Cite journal |vauthors=Vorbach C, Capecchi MR, Penninger JM |title=Evolution of the mammary gland from the innate immune system? |journal=BioEssays |volume=28 |pages=606–16 |year=2006 |pmid=16700061 |doi=10.1002/bies.20423 |issue=6}}</ref><ref>{{Cite journal |author=Goldman A.S. |title=Evolution of the mammary gland defense system and the ontogeny of the immune system |pmid=12751892 |url=http://pages.usherbrooke.ca/infosbio/PSL705/temp/evolution%20immune%20system.pdf |journal=Journal of Mammary Gland Biology and Neoplasia |issue=3 |pages=277–89 |year=2002 |volume=7 |doi=10.1023/A:1022852700266 |s2cid=19388426 |url-status=dead |archive-url=https://web.archive.org/web/20130620033141/http://pages.usherbrooke.ca/infosbio/PSL705/temp/evolution%20immune%20system.pdf |archive-date=June 20, 2013}}</ref><ref>{{cite web|last1=Stannard|first1=Hayley J.|last2=Old|first2=Julie J.|title=Wallaby joeys and platypus puggles are tiny and undeveloped when born. But their mother's milk is near-magical|url=https://theconversation.com/wallaby-joeys-and-platypus-puggles-are-tiny-and-undeveloped-when-born-but-their-mothers-milk-is-near-magical-207726|publisher=The Conversation|year=2023|access-date=October 25, 2023|archive-date=November 10, 2023|archive-url=https://web.archive.org/web/20231110202925/https://theconversation.com/wallaby-joeys-and-platypus-puggles-are-tiny-and-undeveloped-when-born-but-their-mothers-milk-is-near-magical-207726|url-status=live}}</ref><ref>{{cite journal|last1=Stannard|first1=Hayley J.|last2=Miller|first2=Robert D.|last3=Old|first3=Julie M.|title=Marsupial and monotreme milk – a review of its nutrients and immune properties|journal=PeerJ|year=2020|volume=8|page=e9335|doi=10.7717/peerj.9335 |pmid=32612884 |pmc=7319036 |doi-access=free }}</ref>

[[Tritylodontidae|Tritylodontid]] [[cynodont]]s seem to have displayed lactation, based on their dental replacement patterns.<ref>{{cite journal |last1=Hu |first1=Yaoming |last2=Meng |first2=Jin |last3=Clark |first3=James M |year=2009 |title=A New Tritylodontid from the Upper Jurassic of Xinjiang, China |journal=Acta Palaeontologica Polonica |volume=54 |issue=3 |pages=385–91 |doi=10.4202/app.2008.0053|doi-access=free}}</ref>

==Bovine growth hormone supplementation==
Since November 1993, [[recombinant bovine somatotropin]] (rbST), also called rBGH, has been sold to dairy farmers in the US with [[Food and Drug Administration]] (FDA) approval. Cows produce bovine growth hormone naturally, but some producers administer an additional recombinant version of BGH which is produced through [[genetically engineered]] [[Escherichia coli|E. coli]] to increase milk production. Bovine growth hormone also stimulates liver production of [[insulin-like growth factor 1]] (IGF1).

=== Human health ===

The US Food and Drug Administration,<ref>{{cite web |url=https://www.fda.gov/AnimalVeterinary/SafetyHealth/ProductSafetyInformation/ucm130321.htm |title=Report on the Food and Drug Administration's Review of the Safety of Recombinant Bovine Somatotropin |publisher=US Food and Drug Administration |date=April 23, 2009 |access-date=August 25, 2016 |archive-url=https://web.archive.org/web/20160823191323/https://www.fda.gov/AnimalVeterinary/SafetyHealth/ProductSafetyInformation/ucm130321.htm |archive-date=August 23, 2016 |url-status=dead}}</ref> the [[National Institutes of Health]]<ref>{{cite conference |url=https://www.ncbi.nlm.nih.gov/books/NBK15180/ |chapter=Bovine Somatotropin |conference=Technology Assessment Conference December 5–7, 1990 |title=NIH State of the Science Statements |publisher=[[National Institutes of Health]] |year=2002 |access-date=September 5, 2017 |archive-date=November 18, 2015 |archive-url=https://web.archive.org/web/20151118082113/http://www.ncbi.nlm.nih.gov/books/NBK15180/ |url-status=live }}</ref> and the [[World Health Organization]]<ref>{{cite web |url=http://apps.who.int//iris/bitstream/10665/127845/1/9789241209885_eng.pdf |title=Evaluation of certain veterinary drug residues in food |year=2014 |work=[[World Health Organization]] |access-date=August 25, 2016 |archive-url=https://web.archive.org/web/20160803163519/http://apps.who.int/iris/bitstream/10665/127845/1/9789241209885_eng.pdf |archive-date=August 3, 2016 |url-status=live}}</ref> 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.<ref>[https://web.archive.org/web/20100202232114/https://www.fda.gov/Food/GuidanceComplianceRegulatoryInformation/GuidanceDocuments/FoodLabelingNutrition/ucm059036.htm Voluntary Labeling of Milk and Milk Products From Cows That Have Not Been Treated With Recombinant Bovine Somatotropin]. Fda.gov. Retrieved November 24, 2011.</ref>

Milk that advertises that it comes from cows not treated with rBST is required to state this finding on its label.{{Cn|date=May 2025}}

=== Animal welfare ===

Cows receiving rBGH supplements may more frequently contract an udder infection known as [[mastitis]].<ref>{{cite web |url=http://www.preventcancer.com/consumers/general/milk.htm |first=Samuel S. |last=Epstein |title=Milk: America's Health Problem |publisher=Cancer Prevention Coalition |access-date=August 28, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100314123216/http://www.preventcancer.com/consumers/general/milk.htm |archive-date=March 14, 2010}}</ref> 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]]s in milk vary naturally.<ref name="NDSU.EDU">{{cite web |url=http://www.ag.ndsu.edu/pubs/ansci/dairy/as1131w.htm |title=Mastitis Control Programs: Milk Quality Evaluation Tools for Dairy Farmers |publisher=Ag.ndsu.edu |date=January 1, 1997 |access-date=August 28, 2010 |archive-url=https://web.archive.org/web/20100904063426/http://www.ag.ndsu.edu/pubs/ansci/dairy/as1131w.htm |archive-date=September 4, 2010 |url-status=live}}</ref><ref>{{cite web |last=Greger |first=Michael |title=Paratuberculosis and Crohn's Disease: Got Milk? |publisher=[[Vegan Outreach]] |url=http://www.veganoutreach.org/health/greger-gotmilk.pdf |access-date=February 8, 2011 |date=January 2001 |archive-url=https://web.archive.org/web/20110718060100/http://www.veganoutreach.org/health/greger-gotmilk.pdf |archive-date=July 18, 2011 |url-status=dead}}</ref>

rBGH is also banned in the European Union for reasons of [[animal welfare]].<ref>{{cite web |url=http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31999D0879:EN:HTML |title=European Council Decision of December 17, 1999 |publisher=Eur-lex.europa.eu |access-date=August 28, 2010 |archive-url=https://web.archive.org/web/20101028001455/http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31999D0879:EN:HTML |archive-date=October 28, 2010 |url-status=live}}</ref>{{Example needed|date=May 2025}}

==Varieties and brands== <!-- This section is linked to -->
{{main|Dairy product}}
[[File:Dairy Crest Semi Skimmed Milk Bottle.jpg|thumb|upright|Glass milk bottle used for home delivery service in the UK]]
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)
* {{anchor|Hay milk}}farming method (e.g. organic, grass-fed, [[haymilk]])
* 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 [[Ultra-high-temperature processing|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, US, Europe, Latin America, and Australia.

=== Fat content ===
{{Main|Fat content of milk}}
The fat content of whole milk varies, and is adjusted to make different varieties by separating [[skim milk]] from [[cream]], and then using either to mix different ratios, potentially even from the whole milk base. Thereby the different fat content categories are created, like 1%, 2%, and "half and half".

===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 cleavage of lactose into glucose and galactose. Lactose-reduced milk can also be produced via [[ultrafiltered milk|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.<ref name=Peterson2015>{{cite web |last=Peterson |first=Hayley |url=http://www.businessinsider.com/coca-cola-fairlife-milk-review-2015-2#ixzz3Xn6oKt23 |title=We tried Coca-Cola's new milk that costs twice as much as regular{{nbsp}}– here's the verdict|work=Business Insider|date=February 3, 2015|access-date=April 19, 2015|archive-url=https://web.archive.org/web/20150424050647/http://www.businessinsider.com/coca-cola-fairlife-milk-review-2015-2#ixzz3Xn6oKt23|archive-date=April 24, 2015|url-status=live}}</ref> To aid digestion in those with [[lactose intolerance]], another alternative is dairy foods, milk and [[yogurt]], with added bacterial cultures such as ''[[Lactobacillus acidophilus]]'' ("acidophilus milk") and [[bifidobacteria]].<ref>{{cite web |url=http://www.nationaldairycouncil.org/nationaldairycouncil/nutrition/products/product_yogurt.pdf |archive-url=https://web.archive.org/web/20051026104232/http://www.nationaldairycouncil.org/nationaldairycouncil/nutrition/products/product_yogurt.pdf |archive-date=October 26, 2005 |title=Yogurt and Other Cultured Dairy Products |publisher=National Dairy Council |date=2000}}</ref> Another milk with ''[[Lactococcus lactis]]'' bacteria cultures ("[[buttermilk|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.<ref>{{Cite book |author=[[Irma S. Rombauer|Rombauer, Irma S.]] and Marion Rombauer Becker |title=The Joy of Cooking |publisher=Bobbs Merrill |year=1975 |page=533 |isbn=978-0-672-51831-7|title-link=The Joy of Cooking |edition=Revised}}</ref>

===Additives and flavoring===
Commercially sold milk commonly has [[vitamin D]] added to it to make up for lack of exposure to [[Ultraviolet|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.<ref>[http://www.ams.usda.gov/howtobuy/dairy.htm "How to Buy Dairy Products"] {{webarchive|url=https://web.archive.org/web/20071202121113/http://www.ams.usda.gov/howtobuy/dairy.htm |date=December 2, 2007 }}, ''Home and Garden Bulletin 255'', [[USDA]], February 1995. Retrieved May 16, 2007.</ref> 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 US.<ref>{{cite web |last=Main |first=Emily |url=http://www.rodale.com/flavored-milk-and-school-lunch-programs |title=Chocolate Milk Debate Rages On |work=Rodale News |date=November 30, 2009 |access-date=August 28, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100815032450/http://www.rodale.com/flavored-milk-and-school-lunch-programs |archive-date=August 15, 2010}}</ref>

===Distribution===
[[File:Glass milk bottles.jpg|thumb|upright|Returning reusable glass [[milk bottle]]s, used for home delivery service in the UK]]
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 (568{{nbsp}}mL) 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 was concerned that the replacement of the pint bottles with 500{{nbsp}}mL bottles would result in a 13.6% drop in milk consumption; hence, all pint bottles were recalled and replaced by 600{{nbsp}}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.<ref name=wwwa>[https://web.archive.org/web/20080721052114/http://www.zerowastewa.com.au/documents/liquidpboard_fs.pdf Milk and Juice Cartons Fact Sheet], Waste Wise WA, zerowastewa.com.au. Retrieved June 21, 2009.</ref>

Milk is now available in a variety of sizes in paperboard [[milk carton]]s (250&nbsp;mL, 375&nbsp;mL, 600&nbsp;mL, 1 liter and 1.5 liters) and [[plastic bottle]]s (1, 2 and 3 liters). A significant addition to the marketplace has been "long-life" milk ([[Ultra-high-temperature processing|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 three 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]].<ref>{{Cite web |title=AdelaideAZ |url=https://adelaideaz.com/articles/iced-coffee-a-south--australian-global--oddity-that-even--outsold-coca-cola- |access-date=January 4, 2021 |website=adelaideaz.com |archive-date=January 10, 2021 |archive-url=https://web.archive.org/web/20210110235719/https://adelaideaz.com/articles/iced-coffee-a-south--australian-global--oddity-that-even--outsold-coca-cola- |url-status=live }}</ref>

====India====
[[File:Milk vender with typical traditional brass containers , Gagar ,used in Majha Region of Punjab 02.jpg|thumb|Vendors in [[Amritsar]], India transporting milk in [[gagar]], 2019]]

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.<ref>{{cite web |title=Adulterated milk is what Indians are drinking |url=http://cseindia.org/content/adulterated-milk-what-indians-are-drinking |work=Centre for Science and Environment |access-date=June 28, 2015 |archive-url=https://web.archive.org/web/20150625083639/http://cseindia.org/content/adulterated-milk-what-indians-are-drinking |archive-date=June 25, 2015 |url-status=dead}}</ref>

Although India is the world's largest milk producer and a major exporter, the country's ever-increasing demand for dairy products could eventually make it a net importer.<ref>{{cite web |title=Milk quality in India |url=http://www.milkproduction.com/Library/Editorial-articles/Milk-quality-in-India/ |url-status=dead |archive-url=https://web.archive.org/web/20150630141724/http://www.milkproduction.com/Library/Editorial-articles/Milk-quality-in-India/ |archive-date=June 30, 2015 |access-date=June 3, 2015 |publisher=milkproduction.com}}</ref>

====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 (transport)|milk round]] (route) using a [[milk float]] (often battery powered) during the early hours and delivers milk in 1-[[pint]] glass bottles with [[aluminum 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.<ref>{{cite news |last=Coughlan |first=Sean |url=http://news.bbc.co.uk/1/hi/magazine/4850336.stm |title=Milk's online top-up |work=BBC News |date=March 28, 2006 |access-date=August 28, 2010 |archive-url=https://web.archive.org/web/20070901025635/http://news.bbc.co.uk/1/hi/magazine/4850336.stm |archive-date=September 1, 2007 |url-status=live}}</ref> By 2010, the estimated number of milkmen had dropped to 6,000.<ref>{{cite web |title=Find me a Milkman{{nbsp}}– I want doorstep deliveries! |url=http://www.dairyuk.org/for-consumers-mainmenu-278/find-me-a-milkman-mainmenu-290 |publisher=Dairy UK |access-date=February 8, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20101031090238/http://www.dairyuk.org/for-consumers-mainmenu-278/find-me-a-milkman-mainmenu-290 |archive-date=October 31, 2010 }}</ref> 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).<ref>{{cite web |url=http://archive.defra.gov.uk/environment/business/products/roadmaps/milk.htm |title="Milk product roadmaps", The Department for Environment, Food and Rural Affairs |publisher=Defra.gov.uk |access-date=August 28, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20120405054121/http://archive.defra.gov.uk/environment/business/products/roadmaps/milk.htm |archive-date=April 5, 2012}}</ref>

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 carton]]s. 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 carton]]s 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" ({{convert|{{Rnd|236.5882365}}|mL|imppt|disp=comma|frac=12|abbr=on}}) 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===
{{more citations needed|section|date=August 2018}}

[[File:Milk in different packets.jpg|thumb|Milk in different packets]]
[[File:Four litre bagged milk, Quebec.jpg|thumb|Four liter bagged milk in [[Quebec]], Canada]]

[[File:Mejeriprodukter i Skånsk butik.jpg|thumb|right|upright|The milk section in a Swedish grocery store]]
[[File:Milk bottle and two doughnuts.jpg|thumb|285x285px|Milk bottle and two doughnuts.]]
[[File:Milk-bottle.jpg|thumb|upright|A glass [[milk bottle|bottle]] of non-homogenized, organic, local milk from the US state of California. American milk bottles are generally rectangular in shape.{{citation needed|date=May 2014}}]]
[[File:Kirkland Milk Jug.JPG|thumb|upright|A [[Square milk jug|rectangular milk jug]] design used by [[Costco]] and [[Sam's Club]] stores in the United States which allows for stacking and display of filled containers rather than being shipped to the store in [[milk crate]]s and manual loading into a freezer display rack]]
Glass milk bottles are now rare. Most people purchase milk in bags, plastic bottles, or plastic-coated paper cartons. [[Ultraviolet]] (UV) light from [[fluorescent lamp|fluorescent lighting]] can alter the flavor of milk, so many companies that once distributed milk in [[transparency and translucency|transparent]] or highly [[translucent]] containers are now using thicker materials that block the UV light.
Milk comes in a variety of [[carton|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 processing|aseptic]] cartons for up to 1.5 liters, and plastic screw-top bottles beyond that with the following volumes; 1.1&nbsp;L, 2&nbsp;L, and 3&nbsp;L. 1-liter [[milk bag]]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.<ref name=wwwa/>
;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, 250&nbsp;mL aseptic cartons and 500&nbsp;mL plastic jugs.
;Chile
: Distributed most commonly in [[Aseptic processing|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 [[Hong Kong-style milk tea|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 500&nbsp;mL and 1&nbsp;L (sometimes also 200 mL) aseptic cartons. Non-UHT pasteurized milk (''svježe mlijeko/sveže mleko/''свеже млеко) is most commonly sold in 1&nbsp;L and 1.5&nbsp;L 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 2&nbsp;dl and 5&nbsp;dl cartons.
;Germany
: Commonly sold in 1-liter cartons. Sale in 1-liter plastic bags (common in the 1980s) is now rare.
;Hong Kong
: Milk is sold in glass bottles (220 mL), cartons (236 mL and 1&nbsp;L), plastic jugs (2 liters) and aseptic cartons (250&nbsp;mL).
;India
: Commonly sold in 500 mL plastic bags and in bottles in some parts like in the [[Western world|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 various sizes, usually in aseptic cartons.
;Indonesia
: Usually sold in 1-liter cartons, but smaller, snack-sized cartons are available.
;Italy
: Commonly sold in 1-liter cartons or bottles and less commonly in 0.5 or 0.25-liter cartons. Whole milk, semi-skimmed milk, skimmed, lactose-free, and flavored (usually in small packages) milk is available. Milk is sold fresh or UHT. Goat's milk is also available in small amounts. UHT semi-skimmed milk is the most sold, but cafés use almost exclusively fresh whole milk.
;Japan
: Commonly sold in 1-liter waxed paperboard cartons. In most city centers there is also [[Delivery (commerce)|home delivery]] of milk in glass jugs. As seen in China, sweetened and flavored milk drinks are commonly seen in [[vending machine]]s.
;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.<ref name="Tracing the origin of Mursik"/><ref>{{cite web |last1=Neondo |first1=Henry |title=More Kenyans Consume Raw Milk Due to Poverty |url=http://www.cityfarmer.org/milkKenya.html |website=City Farmer |access-date=November 8, 2016 |archive-url=https://web.archive.org/web/20161113231714/http://www.cityfarmer.org/milkKenya.html |archive-date=November 13, 2016 |url-status=live}}</ref> 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 (500&nbsp;mL, 1&nbsp;L, 2&nbsp;L), and non-UHT in 1&nbsp;L 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 (180&nbsp;mL, 200&nbsp;mL, 500&nbsp;mL 900&nbsp;mL, 1&nbsp;L, 1.8&nbsp;L, 2.3&nbsp;L), plastic jugs (1&nbsp;L and 1.8&nbsp;L), aseptic cartons (180 mL and 200 mL) and plastic bags (1 L).
;Sweden

: Commonly sold in 0.3&nbsp;L, 1&nbsp;L or 1.5&nbsp;L cartons and sometimes as plastic or glass milk bottles.
;Turkey
: Commonly sold in 500 mL or 1 L cartons or special plastic bottles. UHT milk is more popular. Milkmen also serve in smaller towns and villages.
;United Kingdom
: Most stores stock [[Imperial units|imperial]] sizes: 1 pint (568&nbsp;mL), 2 pints (1.136&nbsp;L), 4 pints (2.273&nbsp;L), 6 pints (3.408&nbsp;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]]. 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]] (3.78&nbsp;L), half-gallon (1.89&nbsp;L) and [[quart]] (0.94&nbsp;L) containers of natural-colored HDPE resin, or, for sizes less than one gallon, cartons of waxed paperboard. Bottles made of opaque [[Polyethylene terephthalate|PET]] 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 chains in the United States (such as [[Kwik Trip]] in the [[Midwest]]) sell milk in half-gallon bags, while another [[Square milk jug|rectangular cube gallon container design]] used for easy stacking in shipping and displaying is used by [[warehouse club]]s such as [[Costco]] and [[Sam's Club]], along with some [[Walmart]] stores.<ref>{{cite news |url=https://www.nytimes.com/2008/06/30/business/30milk.html?ex=1372564800&en=4b8e1de115184001&ei=5124&partner=permalink&exprod=permalink |work=The New York Times |first=Stephanie |last=Rosenbloom |title=Solution, or Mess? A Milk Jug for a Green Earth |date=June 30, 2008 |access-date=February 22, 2017 |archive-url=https://web.archive.org/web/20161018111823/http://www.nytimes.com/2008/06/30/business/30milk.html?ex=1372564800&en=4b8e1de115184001&ei=5124&partner=permalink&exprod=permalink |archive-date=October 18, 2016 |url-status=live}}</ref>
;Uruguay
: Pasteurized milk is commonly sold in 1-liter bags and ultra-pasteurized milk is sold in cardboard boxes called [[Tetra Brik]]s. 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 125&nbsp;mL paper containers and 100 and 200&nbsp;mL squeeze tubes, and [[powdered milk]] (skim and whole) is distributed in boxes or bags.

===Spoilage and fermented milk products===
{{see also|Fermented milk products}}
[[File:Yakult_drink.jpg|thumb|upright|[[Yakult]], a [[probiotic]] milk-like product made by [[Fermentation (food)|fermenting]] a mixture of [[skimmed milk]] with a special strain of the bacterium ''[[Lactobacillus casei]] Shirota'']]
[[File:Kipsigis_Gourd.jpg|thumb|upright|Gourd used by [[Kalenjin people|Kalenjins]] to prepare a local version of fermented milk called ''[[mursik]]''<ref name="Tracing the origin of Mursik">{{cite web |last1=Kibor |first1=Fred |title=Tracing the origin of Mursik |url=http://www.standardmedia.co.ke/lifestyle/article/2000194283/tracing-the-origin-of-mursik |website=The Standard |date=March 9, 2016 |access-date=November 8, 2016 |archive-url=https://web.archive.org/web/20161109022256/http://www.standardmedia.co.ke/lifestyle/article/2000194283/tracing-the-origin-of-mursik |archive-date=November 9, 2016 |url-status=live}}</ref> ]]

When [[raw milk]] is left standing for a while, it turns "[[sour]]". This is the result of [[fermentation (food)|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,<ref>{{Cite book |title=Culinary nutrition : the science and practice of healthy cooking |last=B. |first=Marcus, Jacqueline |date=2013 |publisher=Elsevier/Academic Press |isbn=978-0-12-391882-6 |location=Amsterdam |oclc=806291270}}</ref><ref>{{Cite book |url=https://books.google.com/books?id=8tlEAgAAQBAJ&q=Pasteurization+of+cow%27s+milk+initially+destroys+any+potential+pathogens+and+increases+the+shelf+life&pg=PA127 |title=Detailed Project Profiles on Dairy & Dairy Products (2nd Edn.) |last=board |first=NPCS |year=2012 |publisher=Niir Project Consultancy Services |isbn=978-93-81039-10-6 |access-date=October 19, 2020 |archive-date=January 25, 2021 |archive-url=https://web.archive.org/web/20210125182629/https://books.google.com/books?id=8tlEAgAAQBAJ&q=Pasteurization+of+cow%27s+milk+initially+destroys+any+potential+pathogens+and+increases+the+shelf+life&pg=PA127 |url-status=live }}</ref> 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 [[acid]]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 [[refrigerator|refrigerated]] and stored between {{convert|1|and|4|C}} in [[bulk tank]]s. Most milk is pasteurized by heating briefly and then refrigerated to allow transport from [[factory farming|factory farms]] to local markets. The spoilage of milk can be forestalled by using ultra-high temperature ([[Ultra-high-temperature processing|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]].

=== Powdered 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.<ref name=hui2006>{{cite book |title=Handbook of Food Science, Technology, and Engineering, Volume 2 |author=Yiu H. Hui |publisher=CRC Press |year=2006 |isbn=978-0-8493-9848-3}} [https://books.google.com/books?id=brdM8-ahRg4C&pg=SA58 p. 58]</ref> It can change the taste by destruction of milk-fat globule membranes, releasing oxidized flavors.<ref name=hui2006/>

==Use in other food products==
[[File:Steamed milk.jpg|thumb|right|[[Steamed milk]] is used in a variety of [[espresso]]-based coffee beverages.]]
Milk is used to make [[yogurt]], cheese, [[ice milk]], [[pudding]], [[hot chocolate]] and [[french toast]], among many other products. Milk is often added to dry [[breakfast cereal]], [[porridge]] and [[granola]]. Milk is mixed with ice cream and flavored syrups in a blender to make [[milkshake]]s. Milk is often served in coffee and tea. Frothy steamed milk is used to prepare [[espresso]]-based drinks such as [[cafe latte]].

==In language and culture==
[[File:From Abhisheka To Panchamrutha.jpg|thumb|upright|left|Hindu [[Abhisheka]] ritual in [[Agara, Bangalore Rural|Agara]], [[Bangalore Rural District]], Karnataka]]

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.<ref name="Leeming">{{cite book |last1=Leeming |first1=David Adams |title=Mythology: The Voyage of the Hero |date=1998 |publisher=Oxford University Press |location=Oxford |isbn=978-0-19-511957-2 |page=44 |edition=Third |url=https://books.google.com/books?id=YJawuz5Q1vEC&q=Milky+Way+Heracles&pg=PA44 |access-date=October 19, 2020 |archive-date=February 23, 2021 |archive-url=https://web.archive.org/web/20210223073744/https://books.google.com/books?id=YJawuz5Q1vEC&q=Milky+Way+Heracles&pg=PA44 |url-status=live }}</ref><ref name="Pache">{{cite book |last1=Pache |first1=Corinne Ondine |article=Hercules |title=Ancient Greece and Rome |date=2010 |publisher=Oxford University Press |location=Oxford |isbn=978-0-19-538839-8 |editor1-last=Gargarin |editor1-first=Michael |editor2-last=Fantham |editor2-first=Elaine |volume=1: Academy-Bible |page=400 |url=https://books.google.com/books?id=lNV6-HsUppsC&q=Milky+Way+Heracles&pg=RA2-PA400 |access-date=October 19, 2020 |archive-date=September 15, 2020 |archive-url=https://web.archive.org/web/20200915083848/https://books.google.com/books?id=lNV6-HsUppsC |url-status=live }}</ref> When Hera awoke, she tore Heracles away from her breast and splattered her breast milk across the heavens.<ref name="Leeming"/><ref name="Pache"/> In another version of the story, [[Athena]], the patron goddess of heroes, tricked Hera into suckling Heracles voluntarily,<ref name="Leeming"/><ref name="Pache"/> but he bit her nipple so hard that she flung him away, spraying milk everywhere.<ref name="Leeming"/><ref name="Pache"/>

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.<ref>Crawford ''et al.'', part B, section III, ch. 1: [http://www.fao.org/docrep/003/t0251e/T0251E15.htm#ch1 Butter] {{Webarchive|url=https://web.archive.org/web/20060203034019/http://www.fao.org/docrep/003/t0251e/T0251E15.htm#ch1 |date=February 3, 2006 }}. Retrieved November 28, 2005.</ref>

Holy books have also mentioned milk. The Bible contains references to the "[[Land of Israel|Land of Milk and Honey]]" as a metaphor for the bounty of the Promised Land. 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. In Jewish religious law, [[Chalav Yisrael]] is the term regulating consumption of milk.<ref>and other dairy products.</ref><ref>{{cite news |date=March 4, 2009 |title=Hamodia Magazine |newspaper=[[Hamoia]] |page=3}}</ref><ref>{{cite book |author=Shain, Ruchoma |url=https://books.google.com/books?id=QdxHnvnHdtMC&pg=PA149 |title=All for the Boss |publisher=[[Feldheim Publishers]] |year=2001 |isbn=1-58330-470-3 |pages=149–150 |authorlink=Ruchoma Shain |orig-year=1984}}</ref>

[[Abhisheka]] is conducted by [[Hinduism|Hindu]] and [[Jainism|Jain]] priests, by pouring libations on the [[Murti|idol of a deity]] being worshipped, amidst the chanting of [[mantra]]s. 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.<ref name="etymonline.com"/> [[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.<ref>{{cite web |url=http://dictionary.reference.com/browse/milquetoast |title=Caspar Milquetoast |publisher=Dictionary.reference.com |access-date=November 17, 2013 |archive-url=https://web.archive.org/web/20131121010417/http://dictionary.reference.com/browse/milquetoast |archive-date=November 21, 2013 |url-status=live}}</ref> 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 to refer to siphoning gas from a car.<ref>{{Cite book |url=https://books.google.com/books?id=5GpLcC4a5fAC&pg=PA943 |author=Green, Jonathon |page=943 |title=Cassell's Dictionary of Slang |publisher=Weidenfeld & Nicolson |isbn=978-0-304-36636-1 |year=2005 |access-date=October 19, 2020 |archive-date=May 8, 2016 |archive-url=https://web.archive.org/web/20160508053353/https://books.google.com/books?id=5GpLcC4a5fAC |url-status=live }}</ref>

==Non-culinary 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,<ref>{{multiref2|{{cite web |url=http://www.abc.net.au/gardening/stories/s948323.htm |title=Fact Sheet: Milk Fungicide |publisher=Australian Broadcasting Corporation |last=Campbell |first=Malcolm |date=September 19, 2003 |access-date=April 1, 2009 |archive-url=https://web.archive.org/web/20160818160904/http://www.abc.net.au/gardening/stories/s948323.htm |archive-date=August 18, 2016 |url-status=dead}}|{{cite web |last=Hoffelt |first=Jeffrey |title=Milk works as fertilizer, says preliminary study |url=http://m.minnesotafarmguide.com/news/regional/milk-works-as-fertilizer-says-preliminary-study/article_028652ea-849c-11e0-9dcc-001cc4c03286.html |archive-url=https://archive.today/20160901045602/http://m.minnesotafarmguide.com/news/regional/milk-works-as-fertilizer-says-preliminary-study/article_028652ea-849c-11e0-9dcc-001cc4c03286.html |url-status=dead |archive-date=September 1, 2016 |work=Minnesota Farm Guide |access-date=June 3, 2015 |date=May 25, 2011}}|{{cite web |last=Phipps |first=Nikki |title=Milk Fertilizer Benefits: Using Milk Fertilizer On Plants |date=November 26, 2012 |url=http://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/milk-fertilizer.htm |publisher=gardeningknowhow.com |access-date=June 3, 2015 |archive-url=https://web.archive.org/web/20150630144851/http://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/milk-fertilizer.htm |archive-date=June 30, 2015 |url-status=live}}}}</ref> 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.<ref>{{cite web |url=https://www.sciencedaily.com/releases/2002/09/020912071438.htm |title=Drop of white the right stuff for vines |work=Science Daily |date=September 12, 2002 |access-date=April 1, 2009 |archive-url=https://web.archive.org/web/20090717041833/http://www.sciencedaily.com/releases/2002/09/020912071438.htm |archive-date=July 17, 2009 |url-status=live}}</ref><ref>{{cite web |author1=Wagner Bettiol |author2=Brenno Domingues Astiarraga |author3=Alfredo José Barreto Luiz |title=<!-- Citation bot stet oblique -->Effectiveness of cow's milk against zucchini squash powdery mildew (''Sphaerotheca fuliginea'') in greenhouse conditions |url=http://www.agrar.de/agenda/bettiol.htm |work=agrar.de |access-date=June 3, 2015 |archive-url=https://web.archive.org/web/20150425043433/http://www.agrar.de/agenda/bettiol.htm |archive-date=April 25, 2015 |url-status=live}}</ref>

[[Milk paint]] is a [[nontoxic]] water-based [[paint]]. It can be made from milk and [[Calcium carbonate|lime]], generally with [[pigment]]s added for color.<ref>{{multiref2|{{cite book |title=Plain and Pleasant Talk about fruits, flowers and farming |last=Beecher |first=Henry Ward |author-link= Henry Ward Beecher |year=1859 |publisher=Derby & Jackson |location=Harvard University |entry-url=https://archive.org/details/cu31924000019772/page/n192 |pages=187–188 |url=https://archive.org/details/cu31924000019772 |entry=Milk paint}}|{{cite periodical |magazine=The Transvaal Agricultural Journal |volume= 4 |publisher= Transvaal Department of Agriculture |year=1906 |title=Useful facts and figures for farmers and fruit growers |page=876 |url=https://books.google.com/books?id=3qoIAQAAIAAJ&pg=RA2-PA876 |access-date=October 19, 2020 |archive-date=February 23, 2021 |archive-url=https://web.archive.org/web/20210223073146/https://books.google.com/books?id=3qoIAQAAIAAJ&q=Milk+paint&pg=RA2-PA876 |url-status=live }}|{{cite book |title=The Painter, Gilder, and Varnisher's Companion: containing rules and regulations in every thing relating to the arts of painting, gilding, varnishing and glass-staining <!-- etc. -->|last=Baird |first=Henry Carey |author-link=Henry Carey Baird |year=1867 |publisher=Henry Carey Baird |location=Philadelphia |pages=97–99 |edition=10th |chapter-url=https://books.google.com/books?id=IcM5AAAAMAAJ&pg=PA98 |chapter=Painting in Milk |access-date=October 19, 2020 |archive-date=February 23, 2021 |archive-url=https://web.archive.org/web/20210223073530/https://books.google.com/books?id=IcM5AAAAMAAJ&q=Milk+paint&pg=PA98 |url-status=live }}}}</ref> In other recipes, [[borax]] is mixed with milk's casein protein in order to activate the [[casein]] and as a preservative.<ref>{{multiref2|{{cite periodical |title=Magic of chemurgy duplicated in the home laboratory |date=February 1942 |magazine=Popular Science |pages=199–201 |url=https://books.google.com/books?id=pScDAAAAMBAJ&pg=PA199 |access-date=October 19, 2020 |archive-date=February 23, 2021 |archive-url=https://web.archive.org/web/20210223073157/https://books.google.com/books?id=pScDAAAAMBAJ&q=milk+paint+Borax&pg=PA199 |url-status=live }}|{{cite periodical |title=How is it Made |last=Wailes |first=Raymond B. |date=March 1940 |magazine=Popular Science |pages=209–211 |url=https://books.google.com/books?id=wCYDAAAAMBAJ&pg=PA209 |access-date=October 19, 2020 |archive-date=February 23, 2021 |archive-url=https://web.archive.org/web/20210223073946/https://books.google.com/books?id=wCYDAAAAMBAJ&q=milk+paint+Borax&pg=PA209 |url-status=live }}}}</ref>

[[File:Milk bath spa in DVN (2413988302).jpg|thumb|right|A milk and rose-petal bath at a spa in Thailand]]
Milk has been used for centuries as a hair and skin treatment. 
<ref name="Arterbery">{{cite web |url=https://www.allure.com/story/the-benefits-of-applying-milk |title=The Benefits of Applying Milk to Your Hair and Skin |last=Arterbery |first=Andrea |date=July 15, 2016 |website=www.allure.com |publisher=Allure |access-date=February 9, 2019 |archive-date=November 6, 2020 |archive-url=https://web.archive.org/web/20201106154609/https://www.allure.com/story/the-benefits-of-applying-milk |url-status=live }}</ref> Hairstylist Richard Marin states that some women rinse their hair with milk to add a shiny appearance to their hair.<ref name="Arterbery"/> Cosmetic chemist Ginger King states that milk can "help exfoliate and remove debris [from skin] and make hair softer. Hairstylist Danny Jelaca states that milk's keratin proteins may "add weight to the hair".<ref name="Arterbery"/> Some commercial hair products contain milk.<ref name="Arterbery"/>

A [[milk bath]] is a bath taken in milk rather than just water. Often additives such as oatmeal, [[honey]], and scents such as [[rose]], [[Asteraceae|daisies]] and [[essential oils]] are mixed in. Milk baths use [[lactic acid]], an [[alpha hydroxy acid]], to dissolve the proteins which hold together dead skin cells.<ref>{{Cite web |url=http://health.learninginfo.org/milk-bath-recipe.htm |title=Milk Bath Recipe |website=health.learninginfo.org |access-date=February 9, 2020 |archive-date=October 3, 2020 |archive-url=https://web.archive.org/web/20201003143933/http://health.learninginfo.org/milk-bath-recipe.htm |url-status=live }}</ref>

==Interspecies milk consumption ==

The consumption of milk between species is not unique to humans. [[Seagulls]], [[sheathbills]], [[skuas]], [[western gull]]s and [[feral cats]] have been reported to directly pilfer milk from the [[elephant seals]]' teats.<ref>{{multiref2|{{cite journal |last1=Sazima | last2= Sazima | first1= Ivan | first2=Cristina |title=Cleaner birds: an overview for the Neotropics |journal=Museu de Zoologia, Universidade Estadual de Campinas |volume=10 |issue=4 |url=https://www.scielo.br/j/bn/a/cx4vzMJnKQMKjDftsVXb5sp/?format=pdf&lang=en |access-date=January 25, 2022 |archive-date=June 10, 2023 |archive-url=https://web.archive.org/web/20230610101547/https://www.scielo.br/j/bn/a/cx4vzMJnKQMKjDftsVXb5sp/?format=pdf&lang=en |url-status=live }}|{{cite book |last=Chester| first=Sharon |title=Antarctic birds and seals |date=1993 | publisher=Wandering Albatross| isbn= 9780963851123 }}|{{cite journal |last1=Gallo-Reynoso|first1= Juan Pablo |first2=Charles Leo|last2= Ortiz|title=Feral cats steal milk from northern Elephant Seals |journal=Therya |date=2010 |volume=1 |issue=3 |pages=207–211 |doi=10.12933/therya-10-14 |doi-access=free }}|{{cite journal |title=Antarctica's Milk-Stealing, Grudge-Holding Seabirds |journal=Boston NPR |date=2016 |url=http://archives.wbur.org/thewildlife/2016/03/29/antarcticas-milk-stealing-grudge-holding-seabirds/ |access-date=February 14, 2022 |archive-date=March 27, 2023 |archive-url=https://web.archive.org/web/20230327163424/http://archives.wbur.org/thewildlife/2016/03/29/antarcticas-milk-stealing-grudge-holding-seabirds/ |url-status=live }}}}</ref>

==See also==
{{columnslist|colwidth=20em|
* [[A2 milk]]
* [[Babcock test]] (determines the butterfat content of milk)
* [[Blocked milk duct]]
* [[Bovine Meat and Milk Factors]]
* [[Dairy and health]]
* [[Fermented milk products]]
* [[Health mark]]
* [[Human breast milk]]
* [[Lactation]]
* [[List of dairy products]]
* [[List of national drinks]]
* [[Milk borne diseases]]
* [[Milk line]]
* [[Milk paint]]
* [[Milk substitute]]
* [[Oat milk]]
* [[Operation Flood]]
* [[World Milk Day]]
}}

==References==
{{Reflist}}

==Further reading==
* [[Natalie Angier|Angier, Natalie]], "Not Milk?" (review of [[Anne Mendelson]], ''Spoiled: The Myth of Milk as Superfood'', [[Columbia University Press]], 2023, 396 pp.), ''[[The New York Review of Books]]'', vol. LXX, no. 16 (19 October 2023), pp.&nbsp;36, 38–39.   "[Americans'] consumption of cow's milk [...] peak[ed in] 1945, when [they] drank an average of forty-five gallons apiece. By 2001 the nation's per capita milk intake had been cut in half, to twenty-three gallons, and in 2021 the figure was down to just sixteen gallons of milk per person, or 5.6 ounces a day... Leading the... drop-off are members of [[Generation Z]]: people born after 1996... Among the [[ecology|eco]]-conscious, antipathy toward dairy milk is great enough that some high-end coffee shops feel no obligation to offer it at all." (p.&nbsp;36.) 
* Dillon, John J. ''Seven decades of milk,: A history of New York's dairy industry'' (1941)
* Innis, Harold A. (1937). [https://archive.org/details/dairyindustryinc0000inni ''The Dairy Industry in Canada''].
* Kardashian, Kirk. ''Milk Money: Cash, Cows, and the Death of the American Dairy Farm'' (2012) 
* Kurlansky, Mark. ''Milk: A 10,000-Year History'' (2019); also published as ''Milk!: A 10,000-Year Food Fracas'' (2019)
* {{Cite book |author=McGee, Harold |author-link=Harold McGee |title=On Food and Cooking |edition=2nd |location=New York |publisher=Scribner |year=2004 |isbn=978-0-684-80001-1|title-link=On Food and Cooking}}
* {{cite journal |last1=Prasad |first1=Rajendra |year=2017 |title=Historical Aspects of Milk Consumption in South, Southeast, and East Asia |url=https://www.asianagrihistory.org/pdf/articles/Rajendra-Prasad-21-4.pdf |journal=Asian Agricultural History |volume=21 |issue=4 |pages=287–307}}
* {{cite journal |last1=Scherbaum |first1=Veronika |last2=Srour |first2=M. Leila |year=2018 |title=Milk products in the dietary management of childhood undernutrition{{nbsp}}– a historical review | url = https://pdfs.semanticscholar.org/51dd/57db105b44d09edd0e2a18e84bf78b061145.pdf | archive-url = https://web.archive.org/web/20200212025231/https://pdfs.semanticscholar.org/51dd/57db105b44d09edd0e2a18e84bf78b061145.pdf | url-status = dead | archive-date = February 12, 2020 | journal = Nutrition Research Reviews | volume = 31 | issue = 1| pages = 71–84 | doi = 10.1017/s0954422417000208 | pmid = 29113618 | s2cid = 910669 }}
* Smith-Howard, Kendra. ''Pure and Modern Milk: An Environmental History Since 1900''. (Oxford University Press; 2013).
* [[Deborah Valenze|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)

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