Effects of dietary carbohydrates on growth and body components of the giant freshwater prawn, Macrobrachium rosenbergii

Abstract

The availability of various dietary carbohydrate sources for juvenile giant freshwater prawn, Macrobrachium rosenbergii, was evaluated according to weight gain and body composition. Different carbohydrate sources, α-potato starch, soluble starch, dextrin, sucrose, glucose and glycogen were separately included in a purified diet. After 60 days the greatest weight gain was achieved in the groups fed potato starch or soluble starch. The group receiving glucose as the carbohydrate source had low weight gain. Food conversion efficiency and the protein efficiency ratio were higher in the group receiving soluble starch as the dietary carbohydrate source. Muscle lipid consisted mainly of phospholipids and partial glycerides; midgut gland lipids were composed of triglycerides and phospholipids. A change in dietary carbohydrates had a minor influence on muscle lipid levels but caused variations in lipid class composition of the midgut gland. Comparatively high levels of free fatty acids and phospholipids were found in the midgut gland of groups fed soluble starch and potato starch, respectively. No major differences in fatty acid compositions were apparent. Soluble starch and potato starch were efliciently utilized by the prawn as dietary carbohydrate sources.