THE FLOW OF THE DIGESTA THROUGH THE DUODENUM AND THE ILEUM OF THE CONSCIOUS SHEEP WITH SPECIAL REFERENCE TO TOTAL NITROGEN AND HEXOSAMINE

In fully conscious sheep the rates of flow of the digesta in the duodenum as observed 25 cm. posterior to the entry of the common bile and pancreatic ducts on grass, hay and hay plus concentrates feeds, were found to be 436 ml., 343 ml. and 453 ml./hr. respectively when fed at 12‐hourly intervals. The rates of flow in the distal portion of the ileum were respectively 91 ml. and 203 ml./hr. in the sheep kept on grass and hay. No significant hour to hour variations were observed in the percentages of total N and total hexosamine in the dry matter of the digesta passing through the duodenum and ileum at these points. By the time the digesta reached this part of the duodenum the dry matter of the feeds had apparently disappeared to the extent of 46 percent, 42 per cent and 50 per cent respectively in the case of the hay, the hay plus concentrates, and the grass feeds. A further disappearance of dry matter took place between the duodenum and ileum, namely 23 per cent for grass and 10 per cent for hay. On the grass diet less N was found to pass along the duodenum than was eaten but in the case of the hay + concentrates the same amount of N passed as was eaten, and on the hay considerably more N passed. There was a very marked increase‐some eightfold‐in total hexosamine passing along the duodenum over the small amount ingested by the sheep fed on grass. In the case of the other feeds there was a threefold increase. In the ileal contents hexosamine still persisted at these same levels. It is considered that the hexosamine found at these locations is partly of rmuninal microbial origin but mainly derived from the mucoproteins of the digestive tract.