The flow of organic and inorganic materials through the alimentary tract of the sheep

The flow of digesta to the duodenum and through the terminal ileum was measured over 24 h periods in sheep fitted with re-entrant intestinal cannulas. A diet of hay supplemented by protein or starch was given. Paper impregnated with chromium sesquioxide was given twice daily by rumen fistula. The chromium was fully recovered in the faeces, though its excretion was rather irregular on a daily basis. Recovery of the chromium in the digesta flow indicated that the duodenal flow was depressed to 85% of the normal value during the 24 h of the flow measurement. Ileal flow was less affected. The mean flows to the duodenum and through the ileum were 8.0 and 3.7 kg/24 h respectively. These values became 9.5 and 3.6 kg/24 h if an adjustment were made to give 100% recovery of the chromium. About 68% of the organic matter digested disappeared in the stomach, 20% in the small intestine and the remainder in the large intestine. About 90% of the cellulose digested disappeared in the stomach and the remainder in the large intestine. The quantities of water, sodium, chloride and phosphorus flowing to the duodenum were much greater than the sheep consumed; potassium showed a smaller increase. The small intestine absorbed most of the water, chloride, phosphorus and potassium. The large intestine absorbed most of the sodium and continued the absorption of water and chloride.