Fig. 1. Methane collection equipment as worn by a grazing cow: (a) collection canister; (b) halter; (c) filter inlet connected to capillary tubing; (d) leather muzzle protector; (e) stainless steel capillary tubing attached to halter; (f) quick-connect coupling of tubing to canister; (g) Teflon tubing between shut-off valve and quick-connect to capillary tubing; (h) shut-off valve on canister; (i) Velcro strip to anchor canister to halter.