Abstract: Disclosed is an ensilaging agent for fodder comprising from about 0.75 to 1 part by weight of an alkali metal salt of nitrous acid, from about 0.3 to 0.8 parts by weight of a compound yielding an aliphatic aldehyde having 1 to 6 carbon atoms during the ensilaging process, and from about 0.15 to 1.5 parts by weight of benzoic acid or a salt thereof for each 1 part by weight of combined nitrous acid salt and aldehyde yielding compound. An improved method is also disclosed wherein the disclosed ensilaging agent is added to fodder in an amount of from about 0.05% to about 0.5% of the fodder weight and comprises from about 0.02 to 0.2% by weight of an alkali metal salt of nitrous acid, from about 0.015 to 0.1% by weight of a compound yielding an aliphatic aldehyde having 1 to 6 carbon atoms during the ensilaging process and from about 0.01 to 0.2% by weight of benzoic acid or a salt thereof for each 1 part by weight of combined nitrous acid salt and aldehyde yielding compound.