Why do cows fart so much?

Cows are ruminant animals, that is, they have four compartments in their stomach. When they eat grass, bacteria in the first compartment, the rumen, softens it. The cow can then bring it all back up into its mouth and chew it again (chewing the cud). Because the process of food breakdown is anaerobic (without air) it produces methane, a powerful greenhouse gas. This is mostly belched, but partly farted.

Agricultural scientists are experimenting with different food additives to try to lessen the amount of methane emissions.

  • There are more than 150 different species of ruminants in all continents except Australia and Antarctica.