Effect of colostomy on nitrogen nutrition in the chicken fed a low protein diet plus urea

Recent interest in the role of the ceca in avian nutrition has focused on recycling of urinary nitrogen through the ceca. In the colostomized chicken, we observed appreciable decrease in utilization of dietary urea nitrogen. This is the first report demonstrating that the ceca are able to play an advantageous role in nitrogen nutrition of the chicken, because back-flow of urinary nitrogen into the ceca was completely inhibited by colostomy. When colostomized chickens were fed a diet containing urea, little urea was found in feces but the amount of urea excreted in the urine corresponded to 77.5% of urea intake. Droppings of normal control chickens fed the same diet did not contain urea. However, they contained twice as much ammonia as the urine plus feces of colostomized chickens, indicating active and great degradation of urinary urea to ammonia by microflora in the ceca of control chickens. The recycling of urinary nitrogen through the ceca may be involved in the utilization of dietary urea by the chicken.