Effect of Weaning Ages on Pancreatic and Intestinal Chymotrypsin Activity in Piglet

<正> Twelve litters of new born piglets were divided randomly into groups I , I , M and F , and weaned at 17, 21, 28 and 35 days of age, respectively, to determine the effect of weaning age on pancreatic and intestinal chymotrypsin activity in piglets. The results showed that the relative and specific activity of pancreatic chymotrypsin increased significantly 12h after weaning compared with that of sucking piglets at the same age and then decreased and remained low for 2 - 3 weeks after weaning. Total pancreatic chymotrypsin activity had no change with the increase of pancreas weight during day 18 - 50 regardless of weaning (P > 0.05). Chymotrypsin activity of jejunum had the same change as that of pancreas during sulking stage. Jejunum chymotrypin activity decreased in the first week post-weaning in the piglets weaned before day 28, but had no change in groups weaned at 28 or 35 days. The earlier the weaning age, the longer the restoring time. Chymotrypsin activity in jejunum is more sensitive to the effec