Dairy farmer says he saves money by converting the manure to electricity . ` In a biodiesel system , all the waste products can either be used or fed back into the digester to make more gas , '' he said . Remaining waste from the cows is used as fertilizer and feed . Anaerobic digestion became popular in United States in 1970s . He says it also helps cut dairy farm 's odor .
Dairy farmer says he saves money by converting the manure to electricity . Remaining waste from the cows is used as fertilizer and feed . Anaerobic digestion became popular in United States in 1970s . He says it also helps cut dairy farm 's odor .