Comparative Studies on Effects of Extruded Pellets and Dough Type Diets on Growth, Body Composition, Hematology and Gut Histology of Juvenile Japanese Eel, Anguilla japonica (Temminck et Schlegel)

摘要

Objective: The present study was conducted to evaluate the effects of two different sizes of extruded pellets and dough type diets on the growth performance, body composition, hematological parameters and gut histology of juvenile Japanese eel, A. japonica. Methodology: A 10-weeks feeding trial was conducted to evaluate the effects of two different sizes of extruded pellets (EP) and dough type diet on the growth performance, body composition, hematology and gut histology of juvenile Japanese eel, Anguilla japonica. Fish with average weight 21.3±1.0 g (means±SD) were fed 3 experimental diets: One dough type diet and two different sizes of Extruded Pellets (EP,- 2 and EP_2- 3 mm) in triplicate groups. Results: At the end of feeding trial, the estimatedweight gain, specific growth rate and feed efficiency offish fed EP diets were significantly higher than those offish fed dough diet (p<0.05). Water quality parameters, such as turbidity, total ammonia nitrogen and total phosphorus from tanks offish fedEP, and EP_2 were significantly lower than those from tanks offish fed dough diet indicating that EP diet was probably pollution free and environmentally friendly. Plasma glutamic oxaloacetic transaminase (GOT) and glucose concentrations were significantly higher in fish fed dough diet compared with those offish fed EP diets (p<0.05). Whole body amino acid composition offish was not significantly affected by the experimental diets (p>0.05). No differences in intestinal morphology or development of pathological lesions were evident in fish fed the diets. Conclusion: The results demonstrated that EP_2 diet could be a more efficient diet to promote improved growth performance and ensure better water quality parameters in Japanese eel aquaculture.