Effect of Barbituric Acid, Chlortetracycline and Carbohydrates upon Growth and Gastrointestinal Urease Activity of Chicks

Results are presented from 100 lots of 15 chicks/lot fed basal diets containing sucrose, dextrose or starch and supplemented with barbituric acid (1.28g/kg) or chlortetracycline (0.1 g/kg) alone or in combination. These supplements when added alone produced the greatest increase in growth with the sucrose diet and the smallest with the starch diet. The 2 supplements in combination did not show an additive effect. The efficiency of feed utilization followed that of growth. Gastrointestinal ammonia production and ureolytic activity were suppressed only when these was an observed increase in growth with the additives. Ureolytic activity in the small intestine was inversely related to the growth response of the various basal carbohydrate diets; however, lowest activity did not reflect greatest gain for all treatments. The response to barbituric acid, a cyclic urea compound, appears to be dependent on the carbohydrate sources, an observation similar to that noted with antibiotics.