Managing bacterial crowds

The rumen contains around 20% of the bodyweight of a cow. The main digestion of the cow’s feed takes place in this enormous organ and is carried out by zillions of microbes – and it takes place in an anaerobic environment. Oxygen is deadly for the system. When in balance the system works pretty well, with one exception – one of the major outputs into the environment is methane (CH4). This greenhouse gas has a global warming potential of 25 compared to carbon dioxide (CO2) over a 100-