text:  And they will control the gases in that chamber to be, you know, relatively like atmospheric gases. So, you know, the cow isn't breathing in anything it wouldn't normally breathe in. And then they'll feed the cow the diet that they want to measure it on. And they will use either, you know, gas chromatography, mass spec, some other way to measure the gases, you know, within that chamber, the gases the cow is emitting.