Effect of Dietary Inositol on Growth, Feed Utilization and Blood Biochemical Parameters for Juvenile Barramundi (Lates calcarifer Bloch)

Problem statement: The utilization of inositol was detected for growth performance and erum biochemical parameters of juvenile barramundi (Lates calcarifer). Approach: A 56 day feeding trial was conducted to evaluate the effect of inositol on growth, feed utilization and serum biochemical parameters for juvenile barramundi Lates calcarifer (initial size 5.51±0.07g). Six experimental fish meal-based isonitrogenous (42% crude protein) and isolipidic (10% crude lipid) diets containing levels of inositol (350, 364, 458, 507, 720, 1050 mg kg^-1 diet) were formulated. Results: Fish fed diet containing inositol 507 mg kg^-1 diet had the significantly highest weight gain (WG, %) among all the groups (p<0.05) and had significantly lower Feed Conversion Ratio (FCR) than fish fed the diet containing inositol 458 mg kg^-1 diet (p<0.05). Survival and Hepatosomatic Index (HSI) were not significantly affected by graded levels of dietary inositol (p>0.05). However, significantly lower Viscerasomatic Index (VSI) was found in fish fed diet without supplemental inositol (p<0.05). Dietary inositol levels did not affect whole body moisture, crude protein and lipid contents (p>0.05). Total protein and triacylglycerol in serum increased with increasing dietary inositol levels up to 507 mg kg^-1 diet (p<0.05). The significantly lowest blood urea nitrogen was found in fish fed dietary inositol 458 mg kg^-1 diet among all groups except for 720 mg kg^-1 diet. Total Cholesterol (TC) of fish fed dietary inositol 507-1050 mg kg^-1 diet was higher than those of fish fed dietary inositol 350-458 mg kg^-1 diet. Conclusion: Results of the present investigation demonstrated significant improvement of growth and feed utilization of juvenile barramundi can be achieved by inositol supplementation at 507 mg kg^-1 diet.