NOVELTY - Managing methane emissions from ruminant, involves: providing mechanism for dispensing feed to ruminant in food tray; first measuring carbon dioxide and methane in air proximate tray; in response to sensing of ruminant, second measuring carbon dioxide and methane in air proximate tray; with data analyzing station, processing measured concentrations to determine increase in carbon dioxide and methane concentration; and with data analyzing station, determining carbon dioxide and methane fluxes for ruminant based on total airflow and on determined increase in carbon dioxide and methane.    USE - For managing methane emissions from ruminant; and for monitoring and controlling methane production by ruminant (claimed).    ADVANTAGE - The method for monitoring gaseous carbon dioxide and methane emissions of ruminants, allows utilizing this information to reduce ruminant methane emissions, to increase ruminant production efficiency, and to monitor health of individual animals. The method can reduce parasitic powerful greenhouse gas (GHG) emissions from livestock and increase grazing efficiency. Thus the method for monitoring and reducing/controlling ruminant methane production has substantial economic potential. The emission of methane as function of gross energy intake is much higher for animal fed low quality forage compared to animal fed high quality diet. It is thus desirable to document relative changes in methane emission rates and to measure fluxes of methane per unit of time, which can provide information to document animal performance changes that lead to quantifiable methane reductions and can generate carbon credits. Thus, measurement of emissions of methane and carbon dioxide from rumen and differentiation of this flux from measurements of carbon dioxide resulting from catabolism over shorter time periods are necessary to track energy flows through specific ruminant and to document efficiency of production of meat and milk in way that facilitates interactive treatment to improve productive efficiency and lower methane emissions per unit of production. In the method changes in ratios of methane compared to carbon dioxide are used to indicate changes in metabolic efficiency, and these measured emission ratios and changes in metabolic efficiencies can be tracked along with additional data which is subsequently stored for individual animal. From gaseous emissions, ruminant's feed supply is adjusted or supplemented or ruminant is otherwise treated to reduce methane emissions.    DETAILED DESCRIPTION - Method for managing methane emissions from ruminant, involves: providing a mechanism for dispensing feed to ruminant into food tray; first measuring carbon dioxide and methane in air proximate to food tray to determine background gas level; sensing ruminant proximate to food tray in feed dispensing mechanism; in response to sensing of ruminant, second measuring carbon dioxide and methane in air proximate to food tray; with data analyzing station, processing first and second measured carbon dioxide and methane concentrations to determine increase in carbon dioxide and methane concentration; and with data analyzing station, determining carbon dioxide and methane fluxes for ruminant based on total airflow and on determined increase in carbon dioxide and methane. The method involves operating data analyzing station to determine, based on determined carbon dioxide and methane fluxes, supplement to be presented in feed dispensed by dispensing feed mechanism to ruminant to control methane emitted by ruminant. The feed dispensing mechanism includes gas collection pipe with inlet adjacent food tray, fan moving air over food tray into gas collection pipe, and airflow sensor measuring air flow in collection pipe to determine total airflow when ruminant is sensed to be in feed dispensing mechanism. The method further involves operating tracer system to discharge quantity of tracer in feed dispensing mechanism, sensing concentration of discharged tracer in gas collection pipe, and with data analyzing station, quantifying capture rate for breath emitted by ruminant during second measuring step and applying capture rate to determined mass fluxes to generate capture rate-adjusted fluxes for ruminant. The total air flow is greater than or equal to 8 times greater than breath emitted from ruminant. INDEPENDENT CLAIMS are included for the following:    (1) apparatus for monitoring methane emissions from ruminant, comprising: device (112) to entice ruminant to voluntarily place its nose and mouth in position that facilitates measurement of exhaled breath; gas collection manifold with inlet near nose and mouth position in ruminant enticement device, where gas collection manifold draws flow of air into inlet; methane monitoring device monitoring methane in gas collection manifold including methane concentrations in exhaled breath of ruminant and in air in absence of ruminant; and data analyzing station processing monitored methane concentrations to determine methane emitted by ruminant from rumen metabolism; and    (2) method for monitoring and controlling methane production by ruminant, involving: with proximity sensor, determining ruminant has positioned its nose and mouth into hood of feeding station (110); while ruminant accesses hood, measuring level of methane and level of carbon dioxide in air flow and concurrently measuring level of tracer in air flow; measuring air flow to determine total air flow in collection pipe; with data analyzing processor, processing measured level of tracer to determine capture rate of breath of ruminant in collection pipe; and with data analyzing processor, determining mass fluxes of methane and carbon dioxide for ruminant, or when ruminant accesses feeder dispenser (122), reading data from tag on ruminant identifying ruminant; accessing methane production monitoring database in memory with identifying data to determine feed mix associated with ruminant; operating dispenser to dispense feed mix into feed dispenser; while ruminant accesses feed dispenser to feed, measuring level of methane and level of carbon dioxide in breath of ruminant; with processing module run by processor, determining metabolic efficiency of ruminant and modifying nutritional supplement in feed mix based on metabolic efficiency to reduce methane production by ruminant; and generating report in user interface of user system that includes metabolic efficiency, identifier for ruminant, and at least one other ruminant management parameter.    DESCRIPTION OF DRAWING(S) - The figure shows front view of system for monitoring and controlling ruminant methane production/emission.    System (100)    Feed station (110)    Hood/manger (112)    Ruminant ear tag reader (114)    Data logger (118)    Feed system (120)    Dispenser/hopper (122)    Feed/chute control mechanisms/assembly (124)    Liquid/granular supplement (126)