Electrophoretic Examination of Alfalfa Silage Proteins

Effects of silage additives on proteolysis of ensiled alfalfa were studied using PAGE. Firstcutting alfalfa was wilted (40% DM), chopped, and ensiled into 60 x lOcm polyvinyl chloride silos. Treatments were control or treatment with gluide (25 g/kg DM), or formic acidformaldehyde (2:l mixture of 90% HCOOH:37% HCOH applied at 1.83% of the DM). Samples were collected on d 0, 1, 2, 4, 7, 21, and 50 of fermentation. Samples were analyzed for N, NPN, ammonia N, pH, lactic acid, acetic acid, and soluble sugar. Also, buffer-soluble protein was characterized using PAGE. During fermentation of control silage, pH and concentrations of soluble sugar declined, and concentrations of lactic and acetic acids and NPN increased, indicating a normal fermentation. Similar shifts in concentrations of compounds occurred in treated silage but to a different extent. Proteins from alfalfa herbage and silage were characterized into molecular weight ranges based on relative mobility, and their disappearance with time of fermentation was estimated. Buffer-extractable proteins decreased rapidly with time COX (50 g/kg DM), ammonium hydrox-