INDUCTION OF EXOCRINE PANCREAS MATURATION AT WEANING IN YOUNG DEVELOPING PIGS

The influence of weaning, at either 4 or 6 weeks of age, on the matura tion of the exocrine pancreas was studied in naturally reared Swedish Landrace pigs that had no access to solid food. The pigs were surgical ly fitted with chronic catheters at 3 weeks of age, permitting periodi c sampling of pancreatic juice and blood in conscious animals less-tha n-or-equal-to 4 weeks after weaning. During the suckling period, pancr eatic fluid and enzyme secretion remained low, both before (preprandia l) and after (post-prandial) milk ingestion. After weaning at 4 or 6 w eeks of age, juice secretion, output of total protein, and levels of d ifferent hydrolases (amylase, trypsin, lipase, and carboxylester lipas e) and the cofactor colipase all increased markedly postprandially. Mo reover, after weaning, the plasma insulin level increased postprandial ly. This did not happen before weaning, although blood glucose levels always rose after feeding. The data showed a relationship between the time of weaning and the induction of exocrine pancreatic maturation in pigs. This finding implies that postnatal development of pancreatic f unction is triggered by the dietary change from sow milk to dry solid food. In contrast, the age of the pig appears to be of minor importanc e, since weaning at either 4 or 6 weeks of age gave a similar result.