Developments in Feeds in Aquaculture Sector: Contemporary Aspects
Aqua feed; Biopolymers; Cellulose; Chitosan; Enzymes; Fish meal; Immunostimulants; Keratin; Polyhydroxyalkanoates; Probiotics; Single-cell protein
Aquaculture, one of the largest protein food generating sectors, greatly relies on nutrition. Up to the present time, the dependency of the aqua feed sector on fish meal and fish oil as protein and lipid sources, respectively, was too high, which led to its inadequacy and over-exploitation of marine resources. Recently, numerous researches with locally available feed ingredients have been accomplished. There is urgency for a move from fish meal to plant/terrestrial animal/microbial proteins within the aquaculture industry as over-exploitation of wild fishes has negative ecological consequences. Plant proteins cannot successfully replace fish meal due to poor protein digestibility and essential amino acids imbalance, urging feed concerns to search for cheaper and nutritious fish meal alternatives from animal origin. In order to overcome the indiscriminate use of antimicrobial drugs, the concept of probiotics in aquaculture has received firm encouragement in recent years due to their wise inhibitory mechanisms and safeness. Negative perception for synthetic antioxidants among fish farmers and their unreliable nature has resulted in the research for non-synthetic, food derived antioxidants that could encounter and neutralize the detrimental effects of free radicals. In line with this, there is a strong captivation to research on the individual or synergistic effects of protein hydrolysates, peptide fragments, and free amino acids that could innately exhibit antioxidative activity. Commercialization of economical feeds with antioxidative feed ingredients could strengthen the profits of feed processors. Recent development in the aquaculture sector propelled by the application of biotechnological methods has clearly highlighted the need for development of functional feeds through incorporation of bioactive molecules. In the last few decades, the global aqua feed industry has witnessed milestones in the development of feed ingredients from waste raw materials and sustainable alternatives to antibiotics and chemicals used to tackle the disease outbreak in aquaculture. As the health and immunity of fishes primarily depend on their nutritional pattern, a great research interest is extended on incorporation of biomolecules like single-cell proteins, animal proteins, plant metabolites, biopolymers, and enzymes as feed ingredients to enhance the nutritive quality and immune tolerance in fishes. Besides the focus on the feed ingredients, the modification and development of fermentation strategies for producing probioticbased feed and enzyme-assisted bioconversion into valuable feed ingredients is also gaining more importance. This chapter deals with the recent development in the aqua feed industry with specific reference to the incorporation of non-conventional feed ingredients like animal/microbial proteins, biopolymers, enzymes, and other immunostimulatory compounds in aqua feed and their impact analysis in improving the growth profile and pathogen tolerance in fishes. The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.
Thazeem B.; Umesh M.; Sarojini S.; Allwyn Vyas G.; Adhithya Sankar S.; Sapthami K.; Suresh S.; Stanly L.M.
Aquaculture Science and Engineering, pp. 35-78.
Thazeem B., Integrated Rural Technology Centre (IRTC), Kerala, Palakkad, India; Umesh M., CHRIST (Deemed to be University), Karnataka, Bangalore, India; Sarojini S., CHRIST (Deemed to be University), Karnataka, Bangalore, India; Allwyn Vyas G., CHRIST (Deemed to be University), Karnataka, Bangalore, India; Adhithya Sankar S., CHRIST (Deemed to be University), Karnataka, Bangalore, India; Sapthami K., CHRIST (Deemed to be University), Karnataka, Bangalore, India; Suresh S., CHRIST (Deemed to be University), Karnataka, Bangalore, India; Stanly L.M., CHRIST (Deemed to be University), Karnataka, Bangalore, India