cattleWhat is Dairy?

When you hear someone say “dairy,” what comes to mind? A glass of milk? Cheese on a hamburger? Yogurt? Ice cream? If you think of any of these, you’d be right! All of these products come from a farmer who raises dairy cattle.

A dairy cow is a cow that is raised specifically for the production of milk. The six main breeds of dairy cows are Ayrshire, Brown Swiss, Guernsey, Holstein, Jersey, and Milking Shorthorn. Another breed – Red and White Holsteins – are a sub-group of the Holsteins. In Iowa today, most milk cows are Holsteins. Farmers have many reasons for choosing what breed of cattle they use for milking. Personal preference plays a big part in this. Other factors in their choice include characteristics like how much milk a cow from that breed will provide, the amount of fat and protein on average in the cow’s milk, and the temperament of the breed.

calf drinking from its mother's udder

See pictures and read more about each breed on the Midwest Dairy website.


History of Milk/Dairy

Not every cow can be a dairy cow. A cow cannot produce milk until it has given birth to a calf. When the calf is born, the cow produces milk to feed the calf. But the calf does not drink every bit of milk. The extra milk can be used by humans.


farmer milking cow at 1850 pioneer farm

History of Milking Machines

The original milking machine was a person! Milking cows by hand was the way it was for done for thousands of years, and can still be done that way. But it takes a LONG time. And if a farmer has dozens of cows, it can take all day!

Throughout the 19th century, farmers searched for a way to make milking a cow less work. Many different kinds of milking machines were tried. But very few farmers used any of these early milking machines. As a matter of fact, some farmers and veterinarians said that using a milking machine would damage a cow’s udder.

In 1895, the pulsator milking machine was invented. The pulsator started and stopped, allowing the teat to fill up again. It was gentler on the cow’s udder than previous machines that used a continuous vacuum to squeeze out the milk.

illustration of surge milkerIn 1921, the Surge Milker was invented. The pulsing movement of this machine was like the calf drinking milk from the cow’s udder. The milking machine hung by a strap over the cow’s back, and was kept close to the udder. This made cleaning the machine’s parts much easier for the farmer. Throughout the 20th century, milking machines became better and more efficient, and the price dropped. More and more farmers purchased milking machines. All of these milking machines still required people to do all of the steps, from cleaning the cow’s udder, to attaching and detaching the machine, and moving the cows in and out.

Historic Methods of Storing and Transporting Milk

farmer holding milk pailAfter the milk comes from the cow, the temperature of the milk is over 100 degrees. It is cooled quickly to less than 45 degrees. When the cow was milked by hand, the milk went into a bucket or pail. There was always the danger of the bucket tipping over when the cow moved or the person milking the cow bumped it!

In 1900, if milk were leaving the farm, it would be transported in metal milk cans. These came in different sizes, but most common were the 10 gallon size. These metal cans would be loaded onto the back of a horse-drawn wagon, and taken either to customers off of the farm, or to the creamery where it would be processed. After the automobile was invented, milk could be transported by truck from the farm to town or the creamery.

This system had many problems. It was very hard to keep the milk cool. The metal cans would not be cleaned properly. Farmers needed two sets of cans, because one set was always gone. Solutions included insulating the truck, and putting big blocks of ice in the truck.

In the 1930s, trucks with mechanical refrigeration began to appear. These trucks used a motor and fans to keep milk cool. These trucks quickly gained popularity.

Processing Milk in 1850

In pioneer days, farm families could make their own butter right on the farm. This is an early example of food processing.


farmer standing next to dairy cowsDairy Production Today

Today, milk can go from the cow to the store in as little as 48 hours. But the work begins almost a year before that! There are many main steps in the process:

  • Caring for the animal continuously
  • Milking
  • Storing the milk
  • Transporting the milk
  • Processing the milk
  • Delivery to the store

Throughout the process, many steps are taken to make sure that the milk is kept safe and clean. Samples are tested continuously to make sure the milk is safe. All machinery, barns, and milking equipment must be kept clean as well.

Video courtesy of Midwest Dairy

Caring for the Cows

cowA top priority for dairy farmers is the health of the animal. Sick or poorly cared for cows will not produce quality milk. Farmers must provide food, water, shelter, and all of the other necessities at all times for the cow’s wellbeing. This includes keeping the areas where the cows live and are milked clean. If you have a pet, you take your pet to an animal doctor called a “veterinarian.” A farmer will have a veterinarian come to the dairy farm regularly to check the health of the cows. If a cow is sick, the vet may give it medicine and then that cow, and its milk, is kept separate from the others until the cow is healthy again.

Farmers may choose to use pastures, open-sided barns, or open lots with shade as places to raise their cows. In barns, dairy cows have the ability to move around, as well as eat, drink, and lie down.

In order to give milk, a cow must have given birth to a calf. The cow is pregnant for about 9 months before giving birth to the calf. That is about the same amount of time it takes a baby human to be born. The cow must be milked at least twice per day. In some cases, a cow is milked 3 or more times per day.

Introduction to the Udder

cow's uddersThe cow’s udder holds the milk. The udder is divided into four parts. Each part has a teat, or nipple. If the nipple is squeezed, and there is milk in that part of the udder, the milk will come out. The cow’s udder and teats must be cleaned before the cow can be milked. The farmer will wash the cow’s udders before beginning to milk. Then the farmer will either begin to milk the cow by hand, or attach a milking machine, which gently squeezes the milk out of the udder.

Milking Machines Today

Systems were introduced in the 1990s that almost completely removed people from the milking process. These were called “Automatic Milking Systems,” and sometimes referred to as “robotic” milking systems. Because the cow chooses when she wants to be milked, these are sometimes also called “Voluntary Milking Systems,” or VMS. According to the Northeast Iowa Dairy Foundation, the steps in the AMS are as follows:

  • Cow enters the robot when she chooses.
  • Feed is dispensed for cow to eat during milking.
  • Teats are recognized and cleaned with brushes and a sanitizing solution.
  • Milking unit is attached to each individual teat, and milk begins to flow.milking machine
  • As each quarter of the cow is finished being milked, the individual inflation detaches.
  • Teat dip is sprayed on each teat to help condition teats and create a barrier for dirt.
  • The cow exits the robot. Before another cow enters the unit performs a rinse to ensure cleanliness.

See a robotic system in action if you visit the Northeast Iowa Dairy Foundation, near Calmar, Iowa.

For a step by step look at the process of automated milking machines, take a look at this article published in June 2017, featuring the Stensland Family Farms near Larchwood, Iowa. The farmers shared their experiences using automated milking machines, and the impact these machines have made on the farm and the cows.

Storing and Transporting Milk Today

Today, when a milking machine is used, the milk goes from the cow through the milking machine to pipes that take the milk to a bulk tank, where it is stored. This is called a “closed system,” and it prevents any contamination of the milk. No human hands will have touched the milk.

milk tank

Refrigerated trucks stop by most dairy farms on a daily basis to pick up the milk and take it to a creamery. The milk trucks are tested to make sure that they are clean and able to move milk safely. Some dairy farms have creameries on the farm, so they do not need to transport milk off of the farm in this way.

Processing Milk

“Processing” means turning raw materials into something usable. Food, or agricultural, processors take raw ingredients and make them into different types of food that people can eat. For example, a creamery will process milk to make cheese or butter or chocolate milk.

Most of the time, processing is done off of the farm. But some farmers in Iowa have creameries on their farm that they can use to process the milk on the farm. At the processor, before the milk is taken off of the truck, it is tested to make sure it is still safe. Then it goes through a three-step process: standardization, pasteurization, and homogenization.

  • Standardization: The liquid milk is separated from the milk fat.
  • Pasteurization: The milk is heated to 161 degrees F for more than 15 seconds to kill bacteria that might make the milk spoil or make people sick.
  • Homogenization: The fat molecules in milk are broken down so that the milk does not separate

Then the milk can be bottled, or made into other products, such as butter, ice cream, and yogurt. Two examples of milk processors are AE Dairy, in Des Moines, IA, and Picket Fence Creamery, near Woodward, IA.


Uses of Dairy Products

After the milk is processed, it can be delivered to the final destination- you! These products are transported by refrigerated truck to grocery stores, schools, or restaurants. There, these products can be enjoyed by you! And that is how the milk on the farm can get to you in 48 hours.

Video courtesy of Midwest Dairy



Dairy: 1. Milk, or products relating to milk; 2. A business where milk and cream are kept, and products from milk such as cheese and butter are made.

Dairy farm: A farm that is devoted chiefly to the production of milk.

Milking parlor: The building on the farm where a cow is milked.

Cattle: Large, 4-legged animals that may or may not be tamed; includes cows, buffalo, and kudus, and other animals like these.

Calf: Baby cattle.

Bull: Male cattle.

Cow: Female cattle.

Dairy cow: A farm animal that is female and produces milk to drink.

Heifer: A young cow at least one year old that has not had a calf yet.

Udder: The part of the body on a cow that stores milk.

Buttermilk: The liquid left behind after making cream into butter.

Agricultural Processor: A place where raw ingredients are transformed into food, or food into other forms of food. A creamery is an example of a milk processor. At a creamery, milk is made into other dairy products like butter and cheese.

Creamery: A place where milk & cream are processed, and where cheese & butter are produced.

Milking Machine (aka “milker”): Something that is used to remove the milk from the cow’s udder.