The agreement between two next-generation laser methane detectors and respiration chamber facilities in recording methane concentrations in the spent air produced by dairy cows

•The Laser Methane Detector (LDM) was tested for measuring methane from dairy cows.•The LMD was suitable to measure low methane concentrations in the air.•The LMD can detect activity differences of cows kept in a respiration chamber.•The data recorded with two LMD and two chamber facilities were in good agreement.•Its utility to measure methane emissions directly on dairy cows has to be shown.