When leaving the King Barn foyer, head down the main aisle, passing on your left the robotic milker, the MOOseum railroad, and the Nutrient exhibit to come to the cow ruminant exhibit.  This exhibit is all about how cows amazingly change plants into milk!

In the world of predators VS prey, cows are prey and so they are built to grab their food quickly and then go off to safer locations to digest it.  In the picture, note the large mouth, long tongue, and teeth only on the bottom of their mouth – all permitting cows to  quickly grab their food and move on to a safer location to digest it.

Cows eat coarse food items that people would never be able to digest!  This United States Department of Agriculture (USDA) poster lists some of these foods.  There are regional differences in what cows are fed, based on what availability.  Cows are ruminant animals. Ruminants are hoofed grazing or browsing mammals that can acquire nutrients from plant-based food by fermenting it in specialized stomach prior to digestion, principally through bacteria, protozoa and fungi action. Cows have 4 compartments to their stomachs which work to digest the coarse food items they eat - foods the human stomach cannot digest.  Cows are not the only ruminant animals – goats, sheep, deer, and giraffes are also ruminant animals.  

People are non-ruminant mammals with a single-compartment stomach.  Digestion begins in the mouth with chewing and ends in the small intestine. As food passes through the GI  tract, it mixes with digestive juices, causing large molecules of food to break down into smaller molecules.  Cats, dogs, pigs, chickens, turkeys, and horses are also non-ruminant.

So, how are these 4 compartments of the cow arranged in the cow?

The 4 compartments are highlighted:   the rumen, the reticulum,  the omasum and the abomasum.  From the mouth, the food is sent down the esophagus. The rumen is the 1st stop for food (purple in the picture)– where microbes break down the feed and make volatile fatty acids which the rumen then absorbs while sending the rest of the feed into the second compartment  – the reticulum.  The rumen is the largest of the 4 compartments and can hold up to 25 gallons of content!  The reticulum (grey in the picture) continues to ferment and soften the food.  Fermentation is the chemical breakdown of a substance by bacterial, yeast or other microorganisms .  Then the softened food is sent back up through the esophagus to the mouth as “cud.”

Wait! What?  Back to the mouth?!?

The cow will chew on its cud for 35%-40% of its day.  Often cows will close their eyes and “sing” as they chew. Chewing the cud continues to break down the coarse food items the cow has eaten.  Chewing on cud is called “ruminating.”  Once softened sufficiently,  the cow will swallow its cud again.

The cud travels thru the first two compartments again for more digestion, and then on to the last two compartments of the stomach – the omasum (orange in the picture) where water and other substances are absorbed into the cow body, and then the abomasum (blue in the picture) where the digestive process is completed.  The abomasum is like the human’s stomach where glands release hydrochloric acid and enzymes that finish breaking down the food.

Food stuff leave the stomach compartments and head to the small intestine, where the now soluble nutrients can diffuse or “leak” through the walls of the intestine into the blood and lymphatic systems.  The small intestines are about twenty times the length of the cow!  Last stop is the large intestine where the water is absorbed, and any undigested feedstuff passes through forming into manure and is then released from the body.

Cow milk is created in her mammary gland called the  udder.  Before milk can be created, the cow must be in “lactation” which is a result of the cow giving birth to a calf.  In the ideal world, cows calve (give birth) every 12 months as they must in order to produce milk.

Cow milk is created in her mammary gland called the  udder.  Before milk can be created, the cow must be in “lactation” which is a result of the cow giving birth to a calf.  In the ideal world, cows calve (give birth) every 12 months as they must in order to produce milk.

The cow’s udder has 4 compartments.  The udder is divided lengthwise by a central wall and then each side is divided by a fine membrane into quarters.  Each quarter will produce milk and each has a teat where the milk leaves the udder.  When visiting the MOOseum, look at the MOO’s Herd and  you will see the line created by the central wall of the udder.  The artist who created the MOO herd was a retired dairy farmer. The fine membranes are not visible unless a microscope is used.

Milk is produced by cells grouped as hollow spheres and tiny storage units called alveoli, which resemble grapes.  The milk will then empty into ducts which carry it to the teat where the milk exits the udder when gentle pressure is applied.

The MOOseum is in the King Barn on the former site of James and Macie King’s dairy farm.  When the King Barn  was built in 1930, cows produced about 2 ½ gallons of milk a day.  Today cows produce about 8 gallons of milk a day. See the USDA poster on how much a cow needs to eat and drink to produce so much milk!  To learn how this phenomenal growth in milk production happened over the years, read about Astronaut the Prize Bull on this website.

When visiting the MOOseum have a docent demonstrate the cow’s digestive system and other systems on this fantastic software!

Hope to see you soon.