A project titled “A rapid cost-effective method to screen potential sources of immunostimulants and growth promoting feed additives for Scylla serrata using a functional genomics approach”, being implemented by the De La Salle University, aims to screen potential sources of immunostimulants and growth promoting feed additives for S. serrata. Currently, there are no commercial immunostimulant enriched feeds for mangrove crab available in the market.
Crustacean feeds with banana peels (Musa acuminata), water hyacinth leaves (Eichhornia cassipes) and a common field grass (Cynodon dactylon) are currently being tested against commercial mucopolysaccharides B-glucan and mannan oligosaccharide or MOS as feed additive to improve the immune response of mangrove crabs to infection. Feed grade B-glucan and mannan oligopolysaccharide are currently used as additives for livestock and are being explored for use in fish feed.
The project has established B-glucan levels with 1:100 ratio to crude dry extract. This will be the ratio that will be used for feed formulation. For the raw materials (10 kgs), 1:10 fresh to dry weight ratio will be used. The feed incorporation rates were also set at 0.25% and 0.5% for the feed additives and the runs last for 15 days after acclimatization
The cost of this locally produced immunostimulants will range from P300-500/kg, which is much cheaper compared to the imported product which costs from P4,000-5,000/kg (freight charges and import taxes not included). The lower price point will allow production of aquafeeds with immunostimulants initially for mangrove crabs and eventually for other crustaceans, and maybe fish.