EXPERT TOPIC GIANT FRESHWATER PRAWN
GIANT FRESHWATER PRAWN
Effects of dietary prebiotic fructooligosaccharide supplementation on growth performance, hepatopancreas histology and intestinal short-chain fatty acids in giant freshwater prawn
by Wee Wen Chen, Master of Science (Aquaculture and Marine Biotechnology)Stéphanie Fontagné-Dicharry3-
quaculture is one of fastest food producing sector in the world. A persistence goal in various type of aquaculture is to maximise the efficiency of production to optimise profitability. The giant freshwater prawn, Macrobrachium rosenbergii is a valuable aquaculture species in many countries due to its commercial value and their aquaculture production has only moderately risen from 196,848 to 213,958 tonnes between 2004 and 2015 (FAO, 2017). Some of the constraints in the expansion of this cultured organism include high feed costs, slow growth rates, poor seeds quality and diseases. Sustainable M. rosenbergii farm production could be achieved when good seedling quality, improved broodstock strain and optimised formulated feed are available to the local prawn hatcheries. Hence, there are few important areas that requires further research. Besides aquaculture system development, genetic and breeding improvement, health and environmental management, evaluation on feed supplementation is necessary for sustainable prawn farming. In addition, the rise in feed ingredient prices also have an impact to 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 health development of the aquatic animals in commercial aquaculture. These problems may potentially be mitigated by dietary prebiotics. Dietary supplements of sustainable feed additives such as prebiotics can impart beneficial effects on fish or crustacean growth and that turn direct into financial benefits by decreasing feed cost per unit growth of aquatic animals. The use of prebiotic appears more practical to stimulate favourable condition for beneficial bacterial in the gastrointestinal (GI) tract of aquatic animal. Also, if the survival, growth performance and feed efficiency of aquatic farming animals are increased, the cost of production is
likely to be reduced. Then, feed additives have a great potential to increase sustainability of aquaculture production. Good formulated feeds supplementation could yield healthy and better growth seedling, resulting in good quality prawns.
Prebiotics are often confused with probiotics. Prebiotics are indigestible food ingredients that may improve the growth and health of the host by promoting the growth of beneficial bacteria in the GI tract (Ringo et al., 2010). When improving the symbiosis between host and beneficial microbiota, this can indirectly improve nutrient utilisation, metabolism, disease resistance, immunity and survivability of the host (Gatlin III & Peredo, 2012). Prebiotics potentially represent eco-friendly additives since these are natural feed ingredients that include alginate, inulin and various oligosaccharides. Although prebiotics are carbohydrates, not all indigestible carbohydrates are prebiotics (for review, see Ringø et al., 2010). Fructooligosaccharide (FOS) and short-chain fructooligosaccharide (ScFOS) are a group of oligosaccharides consisting of beta-linked fructose units ending with glucose and are commonly established prebiotics in the diets terrestrial animals, including humans (Sabater-Molina et al., 2009). In aquaculture, both dietary FOS and ScFOS have gained much interest due to its growth promoting factors on various aquatic species including white shrimp Litopenaeus vannamei (Zhou et al., 2007), narrow clawed crayfish Astacus leptodactylus (Safari et al., 2014) and Asian seabass Lates calcarifer (Ali et al., 2016), etc. Moreover, antioxidant stimulation of prebiotics are well documented, and can include an enhancement to the antioxidant enzyme superoxide dismutase (SOD), as shown into the soft-shell turtle (Ji et al., 2004), triangular bream Megalobrama terminalis (Zhang et al., 2013) and Chinese mitten crab Eriocheir sinensis (Jia et al., 2017). One of the potential benefits to the bacterial fermentation of prebiotics are the production of short chain fatty acids (SCFAs) including acetate, butyrate, and propionate in fish and prawns