Effect of duodenal cannulation on abomasal emptying and secretion in the preruminant calf.

1. The effect of re-entrant cannulation of the duodenum on digesta flow from, and secretion into, the abomasum of the preruminant calf was studied. 2. Calves fitted with abomasal cannulas and, at the same time or later, with re-entrant duodenal cannulas were given, by abomasal infusion, test feeds containing glucose and minerals. Net volumes of secretory fluids entering the abomasum and amounts of digesta flowing to the duodenum were estimated from changes in concentrations of water soluble markers (phenol red and polyethylene glycol) in digesta samples collected from an abomasal cannula. 3. Amounts of abomasal contents, net volumes of secretory fluids and digesta flow to the duodenum for calves fitted with only an abomasal cannula did not differ significantly from those obtained for animals with abomasal and re-entrant duodenal cannulas. 4. Collecting digesta from a re-entrant cannula and returning it promptly to the animal did not affect net volumes of secretory fluids. Under these conditions with cannulas open to the atmosphere, rather than being connected together, the amounts of digesta entering the duodenum increased slightly but differences were not significant. 5. Weight gains of calves fitted with abomasal and duodenal cannulas were similar to those of intact animals. 6. It is concluded that in calves receiving liquid feeds duodenal re-entrant cannulation is a suitable preparation for investigating digestive processes of the abomasum.