EFFECTS OF DIETARY PREBIOTIC FRUCTOOLIGOSACCHARIDE SUPPLEMENTATION ON GROWTH PERFORMANCE, HEPATOPANCREAS HISTOLOGY AND INTESTINAL SHORT-CHAIN FATTY ACIDS IN GIANT FRESHWATER PRAWN (Macrobrachium rosenbergii) POST-LARVAE.

The giant freshwater prawn, Macrobrachium rosenbergii is a valuable aquaculture species in many countries due to its commercial value. Some of the constraints in the expansion of this cultured organism include poor growth rates and diseases. Rising feed ingredient prices also have an impact on the aquaculture production cost. It is possible to reduce the cost of production if the prepared diets not only provide essential nutrients but also increase growth and development of the aquatic animals in commercial aquaculture. These may potentially be mitigated by dietary prebiotics but this research area remains scarce in M. rosenbergii. Prebiotics are indigestible carbohydrate that are capable to stimulate the symbiosis between host and microbiota particularly in the growth of beneficial bacteria which indirectly improves the growth and health condition of the host. Good formulated feeds supplementation could yield healthy and high quality seedling, resulting in better quality prawn. The goal of this study was to study the optimum inclusion level of fructooligosaccharide (FOS) required by M. rosenbergii post-larvae (PL) and the effects of prebiotic fructooligosaccharide supplementation towards the growth and health condition of M. rosenbergii.

The effects of dietary prebiotic FOS additives at 0.1%, 0.4%, 1% and 2% on the growth performance, antioxidant status, intestinal short chain fatty acids (SCFAs) and hepatopancreas histology of the freshwater prawn Macrobrachium rosenbergii PL (initial weight ± SE of 22.8 ± 0.2 mg) were evaluated after 56 days of feeding.

The results showed that the specific growth rate for weight was highest in the 0.4% dietary FOS treatment compared to all others (Table 1). Furthermore, 0.4% FOS also significantly (P < 0.05) stimulated the highest SCFAs production compared to the control treatment. Increasing dietary FOS significantly enhanced the lipid peroxidation and suppressed superoxide dismutase activity (%), indicating oxidative stress to the prawns. Meanwhile, the hepatopancreatic tubules of prawns fed with 0.4% FOS were more closely packed with significantly more R- and E-cells. Based on the FOS inclusion level, 0.4% FOS significantly improved the growth performance and SCFAs production in prawns although FOS trigger oxidative stress in the prawns.