and Yutaka Karasawa

A study was carried out to investigate nitrogen metabolism in response to cecal ligation and colostomy in chickens. We used colostomized plus ceca-ligated chickens fed a low protein diet or a low protein diet supplemented with urea. When both types of diets were fed, nitrogen balance and utilization tended to increase by cecal ligation while total nitrogen excretion tended to decrease. Colostomy increased total nitrogen excretion and decreased nitrogen balance and utilization in chickens fed both types of diets. Therefore, total nitrogen excretion, nitrogen balance and utilization were significantly di#erent between the ceca-ligated and colostomized chicken fed both types of diets (P *.*/). Cecall ligation tended to decrease urinary nitrogen excretion in chickens fed a low protein diet and significantly decreased it in chickens fed the low protein diet supplemented with urea (P *.*/), but did not change fecal nitrogen excretion in chickens fed both types of diets. Total uric acid excretion and urinary uric acid excretion were decreased by cecal ligation (P *.*/) but increased by colostomy (P *.*/) in chickens fed both types of diets. When a low protein diet supplemented with urea was fed, total urea excretion was significantly higher in colostomized than in other three groups (P *.*/), and urinary urea excretion in colostomized chickens was significantly decreased by cecal ligation (P *.*/). Total ammonia excretion was significantly higher in ceca-ligated chickens than those of three other groups fed the low protein diet supplemented with urea (P *.*/), but was similar in the four groups when the low protein diet was given. This indicates that ceca in chickens fed protein-deficient diets may have two di#erent roles in nitrogen utilization : the urine nitrogen retrograded from the cloaca into the ceca is beneficial, but ingesta nitrogen from the small intestine into the ceca is not so. Therefore, collectively chicken ceca could have a negative e#ect in nitrogen utilization in the chicken regardless of having a significant recovery of urinary nitrogen through ceca.