The Value of Several Non-Protein-Nitrogen Compounds as Protein Substitutes in Lamb Fattening Rations

Abstract

Three feeding experiments were conducted with lambs to determine the comparative feeding value of several non-protein nitrogen (NPN) feeding compounds. The compounds studied were urea, ammonium acetate, ammonium propionate, ammonium formate, formamide and propionamide. These compounds replaced as much as 50 percent of the protein nitrogen of the ration. Formamide was found inferior to the other compounds tested. The remaining NPN compounds appeared to be of about equal value in supporting growth as measured by weight gains of lambs. In one experiment, at the 50 percent nitrogen replacement level, the NPN compounds did not support as high rates of gain as conventional protein. However, in another experiment, at the 15 percent and 30 percent replacement levels, weight gains with propionamide and urea were equal to those with conventional protein. Growth data suggested that a period of 2–3 weeks was required for the lambs to become fully adapted to the NPN compounds. This was verified by in vitrostudies in which rumen microorganisms from lambs previously fed propionamide released significantly more ammonia nitrogen from propionamide than did the rumen microorganisms from lambs which had not been so fed. Copyright © . .