How a Cow Digests the Feed She Eats

4‐H Dairy Skills - 11‐year old

The dairy cow has a unique digestive system. She is a ruminant animal, which means she has a four‐chambered stomach. This compared to animals with a simple single chambered stomach, gives her the unique ability to digest fiber and make protein from simple nitrogen compounds. Digestion in ruminants takes place by a process called fermentation, which utilizes microbes found in the stomachs to convert feed into compounds readily digested and easily converted into milk and meat. This makes the cow’s justification for existence compelling because of her capacity to produce high quality food from feeds that man cannot normally utilize.

The digestive system starts with the mouth. A cow does not bite her feed, instead she uses her tongue to sweep feed into her mouth. From the mouth, feed passes through a tube called the esophagus into the first and largest stomach called the rumen. The rumen is very muscular and acts as a mixing vat and fermentation tank. Feed particles that are small in size sink to the bottom of the rumen and pass into the next stomach called the reticulum. Those that are large are regurgitated back into the mouth where they are chewed into finer pieces and mixed with saliva. This process is called “cud‐chewing.” Through chewing and mixing, all feed eventually passes into the reticulum. From the reticulum, this now slurry of ground feed and microbes passes into the omasum, where water absorption takes place. From there the slurry passes into the abomasum. The abomasum is the equivalent of the true stomach. It is there where strong acids are produced and mixed with slurry. Digestion is completed in the intestine where enzymes are produced and absorption takes place. A common digestive disease of cows is the displaced abomasum or twisted stomach. This condition occurs under certain circumstances when gas is trapped in the abomasum causing it to “float” out of place. Most displaced abomasums are repairable with surgery.

Questions

  1. Name the 4 chambers of the cow’s stomach:




  2. What is the process called when a cow regurgitates feed back into her mouth so it can be mixed with saliva and be ground into finer particles?
  3. The fermentation process utilizes _____________ to digest fiber and make protein in the ruminant stomach.

Article Details

Title

How a Cow Digests the Feed She Eats

Series

Dairy Skills 11-year Old

This publication is available in alternative media on request.