How do Cows Make Milk?


For cows to make milk they need to first give birth to a calf. After this, all dairy cows are able to produce milk through a multi-step process.

Dairy Animal Terms

  •  A male dairy animal is called a bull
  • A female dairy animal (prior to giving birth) is called a calve or heifer
  • A female dairy animal (after giving birth) is called a cow

Types of Dairy Cows

 There are six main types of dairy cows.

  • Ayrshire
  • Brown Swiss
  • Guernsey
  • Holstein
  • Jersey
  • Milking Shorthorn.

Cow Facts

  • The average dairy cow typically weighs around 1,000 pounds.
  • No two cows have the same spots 

The Process

There's a multi-step process, that cows go through, to make the milk.

  1. Eating
  2. Digestion
  3. Conversion
  4. Milking

1) Eating

A cow eats, on average, 100 pounds of feed per day. Feed is typically a combination of hay, grain, and silage.

On average, a cow can spend up to 8 hours a day eating. Cows regurgitate food, like grass, that is difficult to digest. This is referred to as "chewing cud".

2) Digestion

After the cow chews her food, it passes into the stomach. A cow's stomach is referred to as a ruminent. It has 4 compartmenst, which is why people think a cow has more than one stomach.

  • Rumen
  • Reticulum
  • Omasum
  • Abomasum

After the food has been digested in the stomach it then passes to the small intestine.

Cow Fact

 A cow can produce an average of 8 gallons of milk per day.

3) Coversion

 After the digested food enters the small intestine, the nutrients are then absorbed into the bloodstream and carried to the utter. Once in the udder, the nutrients are trasformed into milk.

4) Milking

Milking a cow can be done by hand or a machine. Please check out one of the following reources to learn about this process.


Pasteurization is a simple, effective method to kill potentially harmful bacteria without affecting the taste or nutritional value of milk. With standard pasteurization, milk is heated to a temperature of at least 161 degrees Fahrenheit for not less than 15 seconds, followed by rapid cooling.

From the Cow to the Store

After the milk is collected, it normally takes about 2 days before the milk reaches the store. The milk has to be tested for any pesticides or antibiotics. It's then pasteurized and homogenized.

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Comments 43 comments

darkside profile image

darkside 7 years ago from Australia

I've been living in rural Australia now for almost 2 years, SURROUNDED by cows.

As a matter of fact I've got a half a dozen or so in my back paddock that don't belong to me. There's a gap in the fence and I think they must think the grass is greener on the other side.

This has been the most simple, yet understandable bit of information I've come across that explains the how's, what's and why's.

Thank you.

shrl09 profile image

shrl09 7 years ago from Dallas, Texas

I often visited my grand-father's farm as a child and we were always around cows and bulls when we visited there! The only way a cow starts producing milk is when she and a bull breed, she then conceives a calf growing inside of her womb, much like when a woman conceives a child,her body's hormones let her know she is pregnant and therefore her milk glands start to produce milk for her baby soon to be born! The same way works for a cow when the cow is expecting a calf her udders start producing milk for her calf soon to be born!I never milked a cow before but, a cow always produces enough milk for her calf and to be milked! I do remember drinking fresh milk from the cow that my grand-father had just milked and it contains a cream on top and it was very good! Now they have to pasturize the milk according to the FDA standards and I rememember that I drank it a lot and it never effected me! Also you have to watch out for mad cow disease(years ago)and watch what you eat now and eat healthy foods and watch your weight! This according to to the FDA and the American Cancer Society will help us to live longer lives!

idk 7 years ago

I hate u ppl OMG!!!!!!!!!!!!!!!! all of u are free kin nasty!!!!!!!!!!!!!!!!!!!!

luisa 6 years ago

Omg Sos Dnt Kill Coowss...Mooo

Jose 6 years ago

Mmm Is Really Actully Natruly iDnt Know Why Ppl Make A Big Deal About It People Still Drink Milk After All Props People Work In This Im Proud That We Live For This Were Not Beingg Mean But iThink We Should Also Take Care Of Them....!!

boy scout man 6 years ago

this is the best explanathion i've herd for how cows make milk

Dolittle 6 years ago

hey i love killing cows

hi 6 years ago

doesn't the dairy industry artificially inseminate the cow so it becomes pregnant and then they kill the calf and use the mother cows' milk for dairy purposes?

Chapter profile image

Chapter 6 years ago from Indonesia

it is great hubs and explain the milk produce goods.

bailey 6 years ago

This website is really helpful i loved it thanks for all the information.

LAUREN SMITH 6 years ago


ttrash profile image

ttrash 6 years ago from Australia

@hi no, artificial insemination is an expensive process. Most dairy farms simply join cows with a bull at 1.5% (i.e. 3 bulls for 200 cows). Female calves are kept on as dairy cows and bulls are generally sent to slaughter to produce veal.

me 5 years ago

This was somewhat helpful for me to understand how milk is made. However, in the future, I would like to see the 'coversion' told in deeper detail. Lastly, the author needs to check his/her spelling. In the coversion section, the first time they spelled udder, they accidentally spelled it: utter (which would be a completely different definition). :)

ass 5 years ago

i know a better website

leif 5 years ago

too brief

crystal 5 years ago

i think this researh of "how does a cow make milk?"!.

teammates 5 years ago

this is cooooooolllllllll

Are you gay? 5 years ago

I like trains.

Ash 5 years ago

@ttrash in reality most farms do AI their cows for it is the cheaper alternative to the bull, and MUCH less dangerous. bulls become very aggressive when they become of age for breeding and have no problem killing humans and the can hurt cows as well.

deereman 5 years ago

well cows are better then you... and cows get you a burger and milk

Eva 5 years ago

Fresh water crash

ty 5 years ago


Lulu 5 years ago

hate website:(

Cow shagger 4 years ago


Bin there. Dun that. 4 years ago

Cows are totally awesome! Live on a farm and wanna learn everything about cows, bulls, heifers, and calves... I wanna learn how to milk too-- that's probably why there's a video on how to milk cows, right?

me 4 years ago


Goeffrey 4 years ago

I wantd 2 hear more on conversion? Are there reactions,what makes it white- magic or nature, pilizi(please) elaborate more!

ryan 4 years ago


mordecai 4 years ago

all the people who made nasty comments, you guys are real jerks. I mean seriously, it's just nature, if you don't like it, deal with it!

mellissa segura 4 years ago

this is great this website is gay.

divine 4 years ago

really helpful thnx

shin_rocka04 profile image

shin_rocka04 4 years ago from Maryland

Pretty cool and interesting process. Good hub.

dick buttkiss? 4 years ago

i like pie!

dick buttkiss? 4 years ago

I like milk straight from the utters!!!!!!!!

SASASA 4 years ago

Imagine if this process was the same for cows... they milk us!

NerdyMoustache 4 years ago

Comment if u like nerdy ppl and MOUSTACHES!

NerdyMoustache1 4 years ago

Comment if u like MOUSTACHES and nerdy ppl!

ThatBentGuyOverThere 4 years ago



gsudheer kumar 4 years ago

I have 10 jersy cows gives which 10to12 liters per a day for sale at any cost as soon as possible because of i am going states next month ending so contact me on 09247858252.

sammie sweetheart 4 years ago

nice comments guys i like all of the comments.


sammie sweetheart 4 years ago

is there any of yall that's a deer hunter my fiancia got a big 10 pointer buck he is a keeper we would love to see what you have shoot while you spent your time in the woods please feel free to send pic to me on here and i like nerdy people and nerdy moustaches nice goin you guys funny stuff.keep it up.

sammie sweetheart 4 years ago

hey shin rocka nice beat and nice picture

ur mom 3 years ago

really gay diddnt help at all u fagot

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