PANCREATIC EXOCRINE SECRETION DURING THE FIRST DAYS AFTER WEANING IN PIGS

Feed replacement at weaning plays an important role in the induction o f pancreatic maturation. To understand the changes in the exocrine pan creas at weaning and the relation to postweaning problems, we studied the function of the exocrine pancreas and changes of intestinal hemoly tic Escherichia coli in four pigs. The pigs were chronically fitted wi th pancreatic duct catheters and T-shaped cannula inserted into the du odenum for reintroduction of pancreatic juice. One day before weaning (at 36 d of age), pancreatic juice was collected for 1 h before and 1 h after a morning and an evening suckling. The pigs were not creep fed , but from weaning the pigs received a standard weaning diet ad libitu m. On d 1, 2, 3, and 5 after weaning, pancreatic juice was collected c ontinuously for the 24-h period. The total pancreatic secretion was me asured at hourly intervals, 1.5-mL samples were taken for analysis, an d the remaining juice was returned to the animal. On these days, sampl es from the duodenum, ileum, and rectum were also taken for analyses o f hemolytic E. coli. From the day before to 5 d after weaning, a gradu al increase in pancreatic secretion was observed concerning volume (P < .001) and protein (P < .01) and trypsin (P < .02) levels. An increas e (P < .01) in hemolytic E. coli in the duodenal contents was also doc umented during this period. We assume that the gradual increase in the measured variables of pancreatic secretion is related to the increasi ng consumption of solid feed. However, the appearance of E. coli and d isappearance of milk components from the gastrointestinal tract could be other factors stimulating the exocrine pancreas.