1. Two surgical techniques were developed in the calf to study the role of pancreatic secretion in digestion. The secretion was collected through a cannula placed in a small sac of duodenum into which the pancreatic duct drained. The continuity of the duodenum was re-established in the first technique by duodenal re-entrant cannulas, and in the second technique by end-to-end anastomosis of the duodenum with a cannula placed cranial to the anastomosis to return the pancreatic secretion. The accessory pancreatic duct was ligated.2. The flows of digesta through the duodenum of milk-fed calves were 5505, 6369 and 7709 ml/12 h at 7, 24 and 63 d of age respectively, similar to values reported previously in the literature. In a 12 h collection period 297, 441 and 602 ml pancreatic fluid were secreted by calves of 7, 24 and 63 d of age respectively. The secretion from the mucosa of the duodenal sac was 40 ml/12 h in two other calves.3. The rate of secretion from the pancreas varied markedly in milk-fed calves, being lowest 2–3 h and highest 6–10 h after feeding. Changes in the concentration of chloride and bicarbonate with pancreatic secretion rate were indicative of a secretin stimulus to secretion.4. The rates of inactivation of pancreatic enzymes collected from the duodenal sac were measured at 4°, 20° and 39°.
Concurrent studies on the flow of digesta in the duodenum and of exocrine pancreatic secretion of calves
