Abstract
The present study was conducted to investigate whether or not ammonia was responsible for the increased intestinal protein synthesis in the chicken harbouring the conventional gut microflora. In the presence or absence of the gut microflora, the chicks were allowed free access to a practical diet, to which ammonium bicarbonate was added at 4.2g/kg diet, for 10 days from 7 to 17 days of age, and on the last day rate of liver and intestinal protein synthesis was measured by injecting radioactive phenylalanine through a wing vein. The results indicated that almost no significant effect of ammonia supplementation on protein synthesis of the tissues except for the liver was observed in both germ-free and conventional chicks. Thus, at the dietary level tested, which was considered to reflect the amount of ammonia involved in the entero-hepatic recycling, i. e. released in the gut and absorbed by the host bird, biological significance of the role of ammonia in enhanced protein synthesis of the liver and gut by the association with normal microflora was not substantiated.
