The Effect of Feeding Stimulants in Diet on Digestive Enzyme Activities of Eel

Abstract

Pepsin-like, trypsin-like and amylase activities in the gastrointestinal tissue and their digesta were assayed at 3 and 6 h interval after feeding a diet flavoured with alanine, glycine, proline, histidine and uridine-5’-monophosphate on the initial day, day 13 and final feeding day of the experiment. Eel reared on the flavoured diet for 25 days showed remarkably high growth, feed efficiency and energy retention compared with the control group. Although a similar change was recognized in gastric digesta weight of both groups, the flavoured group had significantly higher pepsin-like activities in gastric digesta than the control group. A significant positive correlation between the intestinal digesta weight and trypsin-like activities and high digestibility of dietary protein and carbohydrate were observed in the flavoured dietary group. Whereas higher trypsin-like and amylase activities and digesta weight in intestinal tract were determined in the control group, no relationship between intestinal digesta weight and their trypsin-like activity was recognized. These findings suggest that the feeding stimulants in the diet, stimulates the feeding activity of the fish and promotes the digestion and absorption of the diet. © 1986, The Japanese Society of Fisheries Science. All rights reserved.