Métabolisme de l’urée dans le tube digestif du porc : données préliminaires qualitatives et quantitatives

Abstract

Urea metabolism in the digestive tract of the pig : preliminary quantitative and qualitative data. The previously reported direct method of determination of the exchanges of nutriments between blood and digestive contents (Rerat, 1977) was applied to the study of the passage of blood urea towards the intestinal lumen and its metabolization into ammonia in the pig. Using five replications at different feeding levels it was possible to compare in one and the same animal diets containing 12 p. 100 protein and either no urea or 3 p. 100. The amount of blood urea permanently secreted in the gut during digestion of a balanced meal in healthy animals ranged around 1 gramme per hour. The urea secreted was only partially degraded (less than 50 p. 100) into ammonia. Dietary urea was rapidly absorbed (within about 5 hours) and its addition to the diet did not lead to a significant elevation in the amounts of ammonia produced during the postprandial period (8 h) in animals non adapted to this addition of urea.