The balance between amino acids and nitrogen is important to consider when formulating diets. When diets are low in nitrogen non-essential amino acids are also lowered, and the nitrogen needed to produce non-essential amino acids to build muscle protein will come from other amino acids in excess, or from non-protein nitrogen. This study tested the supplementation of ammonium salts to provide non-protein nitrogen when non-essential amino acids were limited, as would occur in a low protein diet. Increasing amounts of non-protein nitrogen increased feed efficiency compared to a low protein negative control, decreased feed intake, and did not affect weight gain.