Future demand and supply of aquafeed ingredients: Outlines to commercialize non-conventional protein ingredients to enhance aquaculture production for food security in sub-Saharan Africa

Abstract

Aquaculture, being the fastest growing food sector, is expected to provide the highly needed animal protein for about 9.7 billion people globally by 2050. The world population is likely to consume 178 million tons of food fish/aquatic animals by 2028, whereby 58% of fish will likely be from aquaculture. Growth of food fish production is expected to increase overall production of aquafeeds to over 87 million tons by 2025. Aquafeed production relies largely on fishmeal which is getting expensive due to its multiple use and scarcity. A remedy to this situation is the use of non-conventional protein sources, which may be of plant (leaves, cereals, pulses etc.) or animal (insects, worms, etc.) origin. This paper demonstrates the potential of non-conventional ingredients for aquaculture. It was found that crude protein levels of selected non-conventional plant ingredients ranged from 25-71% while those of animal origin were from 66-72%. Inclusion levels of 5-40% and 25-66% were recommended in aquafeeds, respectively, from ingredients of plant and animal origin. Performances of fish fed aquafeeds containing selected non-conventional ingredients have been reviewed. Presence of anti-nutrients, chitin and high lipid in feed ingredients, and shortcomings in processing and mass production technologies, have been identified as the main challenges limiting the commercialization of the selected feed ingredients. To remove the unwanted factors and to enhance inclusion of non-conventional ingredients in aquafeeds, authors suggested varied strategies. The strategies such as defatting, heat treatment, extrusion cooking, solvent extraction, dehulling, fermentation, ensiling, genetic modification and inclusion of enzyme are identified as some of the most efficient methods. Effective and affordable technologies to improve nutritional value should be validated through research for adequate and consistent supply of aquafeed in Sub-Saharan Africa. Consequently, provision of sufficient, quality and affordable aquafeeds will promote sustainable aquaculture production and reduce fishing pressure and pollution in natural aquatic ecosystems.