The Influence of Oral Administration of Non-Protein Nitrogen Feeding Compounds upon Blood Ammonia and Urea Levels in Lambs 3

Abstract

Ten NPN compounds were administered orally to lambs for purposes of determining their toxicity. These compounds were administered in progressively larger doses and blood samples were taken at varying intervals following administration. Ammonia and urea nitrogen were determined on 350 blood samples taken from thirty lambs in studying the toxicity of urea, ammonium formate, ammonium acetate, ammonium propionate and propionamide. Limited observations were made upon fifteen lambs using ammonium succinate, formamide, guanidine carbonate, biuret and glycine. In all cases except with guanidine carbonate, toxicity was associated with large increases in blood ammonia nitrogen, with the critical level being about 1 mg. per 100 ml. of blood. Administration of urea, ammonium formate, ammonium acetate and ammonium propionate at a level of about 40 gm. urea equivalent resulted in fatal toxicity. Fatal toxicity not associated with an increase in blood ammonia nitrogen was observed after administration of guanidine carbonate at the 30 gm. urea equivalent level. Little if any increase in blood ammonia and urea nitrogen attended the administration of the other compounds. Symptoms of fatal toxicity were alleviated by oral administration of adequate amounts of acetic acid.