Development of porcine digestive enzymes with special reference to ribonuclease

The activity of digestive enzymes was determined in the gastrointestinal tract of newborn, 1-, 3- and 5-week-old piglets and in adult pigs. The pancreas of newborn piglets contained considerable ribonuclease (RNase) activity, which continued to increase with age. After the initial values an opposite tendency was found in the intestinal contents, probably due to the increase of proteolytic degradation with advancing age. Serum RNase showed little age dependence. The time-course of development of pancreatic RNase resembled more that of proteolytic enzymes than tha of amylase. The data indicate that a high pancreatic secretion of RNase commences much before the appearance of RNA in the diet.