A note on the substitution of protein by non-protein nitrogen in beef rations

Abstract
Many observations have been made on the metabolic effects of urea (see reviews by Reid, 1953; McLaren, 1964) and on the problem of urea poisoning (Repp, Hale and Burroughs, 1955), but little information is available on the use of urea for fattening beef cattle under conventional intensive systems. There has been considerable interest shown in the use of biuret as a source of non-protein nitrogen (NPN) as it has been found to be less poisonous than urea when consumed in large quantities (Berry, Riggs and Kunkel, 1956).