Do cows live on bacteria

Answer 1

Yes. It's a little known fact that cows gain much of their nutrients from bacteria they both digest to get much of their protein from, and from what the bacteria release and synthesize as they break down plant material the cow ingested.

These bacteria live in the reticulo-rumen complex of the cow (two of the three forestomachs) along with fungi and protozoa, and are crucial in synthesizing an enzyme called cellulase that is used to break down the cellulose found in all the forages the cow consumes--not just grass. Cellulose is predominantly found in the cell wall of the plant cell, and is what helps give plants their structure. Once this organic chemical is broken down, all the other nutrients within the plant cell is released to be taken up by the micro-organisms in the rumen. What is not taken up by the microflora is transferred to the cow through the rumen wall. (Nutrients are also taken up through the reticulum and omasum.)

Since the bacteria in the cow's rumen only have a life span of around 15 minutes, many dead bacteria are moved through reticulo-rumen contractions into the abomasum where they are digested. The cow receives around 40 percent of its protein from these dead bacteria.

As mentioned above, nutrients are released once the plant-cell walls are broken down by the microflora. These nutrients that are a) not digested by the micro-organisms or b) not absorbed through the rumen, reticulum or omasum wall into the bloodstream are further digested and absorbed through the abomasum and small intestine. The abomasum is the true stomach of the cow which functions--as does the small intestine--very much like ours.