Effect of Additives on Fermentation of Corn Silage Containing Different Amounts of Added Nitrate Nitrogen

¹ Department of Animal Science, University of Minnesota, St. Paul 55108

Ammonium hydroxide, urea, calcium carbonate, and microbial inoculant were added to chopped whole corn plant containing different amounts of added nitrate. Chopped corn was ensiled in .002-mm plastic bags and fermented for 0, 1, 3, 7, 14, and 28 d. In Experiment 1, chopped whole corn plant was treated with ammonium hydroxide, calcium carbonate, microbial inoculant, or no additive. Potassium nitrate was added to each treatment to obtain 0, .200, .400, or .600% nitrate N in DM. In Experiment 2, chopped corn plant was treated with urea, calcium carbonate, or no additive. Nitrate N was added to each treatment at 0, .238, .477, and .953% of DM. Control and microbial-inoculated silages had similar concentrations of lactic acid, acetic acid, and ammonia and similar pH. Addition of urea and ammonia increased initial pH and slowed the decrease in pH compared with the control and with silage treated with microbial inoculant. Calcium carbonate increased concentrations of lactic and acetic acids compared with the control during Experiment 1 but had no effect on concentrations of these acids in Experiment 2. Treatments were ineffective in reducing nitrates. Addition of nitrates tended to increase silage pH but had only minor effects on concentration of lactic acid, acetic acid, and ammonia.

Key Words: fermentation • nitrates • corn silage

Submitted on November 18, 1991
Accepted on January 27, 1992