Volatile Constituents of Grass and Corn Silage. II. Gas-entrained Aroma

The volatiles entrained from several grass and corn silages and condensed in cold traps were analyzed by gas-liquid chromatography. The volatiles from the grass silages were found to be mixtures of methylsulfide, ethanal, propanal, acetone, butanone, methanol, ethanol, propanol, 2-butanol, methyl acetate, "and the ethyl and propyl esters of formic, acetic, propionic, and butyric acids. While methylsulfide, ethanal, methanol, ethanol, methyl acetate, ethyl formate, and ethyl acetate were commonly detected in the corn silage volatiles, propanal, acetone, butanone, propanol, 2-butanol and other esters were not consistently detected, and the butyrates were usually absent. Rapid transmission of some or all of these compounds to the mammary gland via the respiratory system is believed to be responsible in part for the development of feed flavor in milk from cows fed silage.