New ear-tag methane sensor rivals industry standard in field trial
Harvard researchers tested a novel methane sensor called GRAZE-Tag against the industry-standard GreenFeed system on cattle. The sensor, designed to measure enteric methane emissions in real time, performed comparably in early field tests. This could help farmers monitor and reduce methane emissions from livestock.
The GRAZE-Tag is an ear-mounted device developed in Joanna Aizenberg's Harvard laboratory, designed to detect enteric methane released through cattle burps. During the June field trial at UC Davis, researchers installed the sensors with assistance from farm crew members and compared readings against the GreenFeed system, which requires cattle to visit a stationary measurement station.
The trial involved collaboration with Ermias Kebreab's team, a recognized authority on livestock methane. Early data showed the ear tag's detections closely tracked GreenFeed's measurements. The work appears in Advanced Materials Technologies, marking a transition from laboratory validation toward practical farm deployment.
If validated through further testing, low-cost ear-tag sensors could enable farmers to monitor methane emissions across entire herds in real time, rather than sampling small groups at fixed stations. This may help researchers evaluate which feed additives, genetics, or management practices actually reduce emissions under working farm conditions. Widespread adoption could support climate targets by making methane reduction measurable and ver