The Release of Ammonia Nitrogen from Urea, Ammoniated Molasses, and Soybean Oil Meal in the Presence of Rumen Microorganisms ,

Abstract

Summary Four series of experiments have been employed to determine the relative amounts of free ammonia nitrogen released from urea, ammoniated cane molasses (15.4% protein equivalent), ammoniated invert molasses (33.3% protein equivalent), and soybean oil meal in the presence of rumen microflora and the enzyme urease. In the first fermentation series, urea and the two ammoniated molasses were compared by means of the artificial rumen technique. In the second fermentation series, soybean oil meal and the two ammoniated invert molasses were compared by means of an artificial rumen. Urea, soybean oil meal, and the two ammoniated molasses were incubated for 1 hour at 40° C. with and without the presence of the enzyme urease in the media. In a fourth experiment, urea and the two ammoniated molasses were added to the rumen of a fistulated steer subsisting on a diet of Korean lespedeza hay. The level of free ammonia nitrogen in the rumen liquor was determined. Evidence is presented to indicate that there was some free ammonia in both samples of ammoniated molasses. The amount of free ammonia associated with these materials did not increase significantly with prolonged fermentation in an artificial rumen, nor was there a significant amount released in the presence of the enzyme urease. Considerable amounts of ammonia nitrogen were released from urea in the presence of microflora both in vitro and in vivo and in the presence of the enzyme urease. The release of ammonia nitrogen from soybean oil meal approximated that in a control flask in the presence of rumen microflora in an artificial rumen. The enzyme urease effected release of a significant amount of ammonia nitrogen from soybean oil meal, but this amount was very small compared to the amount released from urea.