Elodie Moos


Digesting grass is certainly not a piece of cake! You humans would not be able to do it at all…but it’s a walkover for us cows, as it is for all other ruminants!

Try it out!

Drag a bit of grass through my ingenious digestive system and find out how it works!


1. Oesophagus

Cows have no less than four stomachs: three preparatory zones and one actual stomach! That’s just as well, since we swallow grass that we graze without even chewing it. But then we produce almost 200 litres of saliva a day! When it is finished with our jaw, the grass first of all goes to the rumen via the oesophagus.

2. Rumen

The rumen is the first of our four stomachs. It can store almost 200 litres of grass and water. The heat there means that the mix begins to ferment, which happens after several billion bacteria and micro-organisms get to work on it.

3. Reticulum

In the second stomach, the reticulum, the fermented mixture is transformed into small pellets. We regurgitate it via our oesophagus so that it can be masticated a second time, which is why we are referred to as ‘ruminants’.

4. Omasum

Having been properly masticated, the grass that has now been reduced to a mush arrives in the omasum where it is separated from its liquid. It is here that micro-organisms are absorbed (such as sodium and phosphorus). The smallest blades of grass then make their way to the fourth and final stomach, the abomasum.

5. Abomasum

The abomasum has the same function as the stomach of you humans. This is where ‘real’ digestion takes place. Gastric acid removes bacteria and digests it, and the final food elements are finally dissolved. Once the grass leaves the abomasum it no longer looks much like grass!

6. Small intestine

Nutritional elements such as lipids, proteins and carbohydrates are absorbed into the bloodstream all along the small intestine that measures 50 metres - so isn’t actually all that small. The route to the teat is not all that long, and that is where the milk is produced from the nutrients that have been ingested.

7. Large intestine

The final stage takes place in the large intestine. That stage involves the bacteria getting to work on the few remaining nutrients, while also eliminating the liquid still remaining in the mush. Lots of splendid cowpats are formed here that will end up on the meadow, to the benefit of the plants that grow there – and so it goes full circle!

Cheesy Quiz

1. Which of these animals is not a ruminant?
a. Goat
b. Hippopotamus
c. Fox
d. Giraffe
e. Stag

Which of these is the odd one out?
a. Abomasum
b. Stencil
c. Rumen
d. Reticulum
e. Omasum

What is the length of the average adult cow intestine?
a. 50 centimetres
b. 1 metre
c. 8.5 metres
d. 31 metres
e. 50 metres