602695 Disclosed is a method and detection device for detecting greenhouse gases such as methane (3) emitted by a ruminant (1) when producing an eructation. The method comprises measuring a signal using a sensor related to the eructation and determining from the signal the number and/or the time duration of the eructation using a control device (6). The signal comprises a sound signal measured from the mouth (5) or throat of the ruminant (1) using a microphone (7). The signal further comprises a pressure signal measured from the gut (2) of the ruminant (1) using a gut pressure sensor. An eructation is counted when there is a pressure drop within a predefined time period. The signals are filtered to meet predefined requirements.
