Alternation of gastric emptying, feeding behavior and digestive enzyme activities in Hexagrammos otakii

In order to determine the optimal feeding interval and frequency for Hexagrammos otakii, taking H. otakii Average body mass of (73.19±6.68) g as research object, we observed the proportions of stomach contents at different time after feeding, then compared the fitting degrees of the square root model, cubic model and linear model on the gastric emptying curve, and analyzed the changes of serum cortisol and glucose contents, intestinal and liver digestive enzyme activities after feeding. The results show that the gastric emptying of H. otakii followed a typical linear descending pattern. All the three models could fit the gastric emptying data, especially the cubic model fitted the best. 80% gastric emptying took about 15 h after feeding; basic emptying (97.7%) took about 18 h; complete emptying took about 19.7 h. The serum cortisol, glucose level, and the activities of intestinal and hepatic digestive enzymes (Amylase, chymotrypsin, and lipase) increased significantly from 0–6 h after feeding, peaking at 6^th hour (p<0.05), but then decreased significantly. The intestinal amylase decreased to the minimum values at 15^th hour after feeding (p<0.05). The activities of liver chymotrypsin, liver lipase and serum cortisol levels decreased to the minimum values at 18^th hour after feeding. The instantaneous emptying rate was positively correlated with the contents of glucose, cortisol and digestive enzyme activities. In conclusion, the physiological critical point of gastric emptying and digestion is 15 h after feeding in H. otakii, and the optimal feeding frequency for H. otakii is twice a day.