A method and system for reducing methane emissions by ruminants. The method includes providing a feed dispenser for feeding ruminants nutrient supplements, and the feed dispenser includes a gas analyzer where a ruminant places its head. The method includes determining a particular ruminant has accessed the feed dispenser such as by reading an identifier from an RFID ear tag and operating the feed dispenser to provide a ration of methane-controlling nutrient supplement. The method includes using the gas analyzer to determine levels of carbon dioxide and methane and operating a data analyzing station to determine a ratio of methane to carbon dioxide and modify the type or amount of nutrient supplement for the ruminant for a next feeding to control methane production or achieve an animal production goal, such as by operating a hopper with supplement compartments. The unit can be monitored remotely and controlled through an Internet connection.