Milk collection system

We saw how the cows get ready to be milked, and how the milking machines are attached to the cows. There’s lots of cleaning that goes on to get the cows ready in the milking parlor!

But once the milking process is started, what happens then?

Once the milking machine is put onto the cow’s udder, the milk is never touched by human hands. The milk flows through the milking machine to a complex system of stainless steel pipes.

First, the milk flows through the plastic tubing and past a sensor that measures the flow rate. The green light on the platform tells the workers how the milking is going. A green light means the milk is flowing well; a flashing yellow light means the milk is slowing down; and a red light means this cow is finished milking and the milker is ready to fall off.

All the milk is collected in the stainless steel pipe (the milk line) that runs across the bottom of the photo above. The milk flows by gravity through the milking parlor and behind a wall. The milk line runs from the right of this photo into the round pump. (The milking parlor is just to the right of this photo – see the cow’s head in the background?)

The pump here pumps the milk overhead and into the next room. The milk is briefly collected into this bulk tank. From here, it goes to the cooling system.

Using a network of stainless steel tubes, cold water, and a refrigerant, the milk is cooled from around 100 degrees Fahrenheit (the body temperature of a cow) down to 35 degrees Fahrenheit in only 15 seconds! The cold water cools the milk down to 70 degrees, then the refrigerant cools the milk the rest of the way to 35 degrees.

The milk never actually touches the water, the tubes holding the milk and the tubes holding the water and refrigerant pass each other, and the heat is transferred through the metal of the tubes. The water used for cooling the milk is recycled and later used to water the cows. (Conservation in action!)

After the milk comes out of the cooling system, the temperature is recorded. This gauge shows the current temperature of the milk (33 degrees Fahrenheit), and the graph tracks the temperature of the milk (the lines near the outside of the circle) and the temperature of the wash cycles (the spikes towards the center of the circle). This graph keeps a temperature record for a few days at a time.

After the milk has been refrigerated, is flows through this flexible tube, and outside the milking parlor.

It is stored on this 6000-gallon insulated tanker. Because the tanker is not refrigerated, the milk will slowly warm up over time, but only by 1 degree a day. And these tankers are picked up every day and delivered to the processing plant. The goal is to load the truck with milk around 36 degrees Fahrenheit, and this will reach the plant at 37 degrees, which is still plenty cold!

Not only is the milk never touched, but it is never seen once the cows are hooked up to the milk machine! The milk isn’t actually seen until it reaches the processing plant. There, samples are taken from each batch of milk for testing before the tankers are unloaded and milk processing starts.

The New Generation Dairy produces around 11,000 gallons of milk every day. They have two of these tankers on the farm at any given time. Twice a day, a driver comes to drop off an empty tanker and picks up a full tanker.

New Generation Dairy is one of only 9 dairies in Indiana that loads their milk directly onto a tanker. Many other dairies have a large bulk tank for milk where it is stored until the tankers come to pick the milk up. New Generation Dairy produces enough milk every day that it makes more sense for them to load directly onto the tankers.

Everything that is used to milk the cows is completely cleaned between each milking, three times a day. They clean the floors and walls of the milking parlor, each individual milking machine, and all the piping of the milk collection system. There are five cycles every time the milk lines are cleaned – a rinse cycle, three cleaning cycles, and a final rinse cycle. This is just one more way dairy farmers work to ensure food safety in dairy products.

All the milk from the New Generation Dairy is taken to a dairy processor in Kentucky. This milk is all used as “fluid milk” after some processing, or the milk you purchase in half-gallon or gallon containers from the grocery store. Other dairies produce milk that is used for yogurt, cheese, or other dairy products.