Aquafeeds have been the main sustainable platform for the aquaculture industry in Africa, as they provide essential nutrients needed for the growth, health and productivity of the farmed fishes. Without high-quality aquafeeds, it would be challenging to meet the increasing global demand for farmed fish. Conventional feedstuffs like fish meal, soybean meal, groundnut meal, maize and cowpeas used for preparing aquafeeds are becoming scarcer and more expensive, due to issues of sustainability, competitive use by humans and livestock, resource availability, cost-effectiveness and the effect of climate change thus making the use of aquafeeds unsustainable. Consequently, the use of conventional animals and plant feedstuffs in fish nutrition may no longer be sustainable. Therefore, there is a need to explore alternative fish feed ingredients that are locally available, low-cost, nutritious and sustainable to reduce dependence on traditional raw materials. This paper, therefore, provides an overview of the current challenges with the use of raw ingredients in aquafeeds and explores the potential benefits and challenges associated with alternative ingredients. It also discusses the role of alternative fish feed ingredients in the sustainable development and promotion of commercial aquaculture in Africa
Traditional raw ingredients like fishmeal, fish oil, maize and soybean meal have been widely used in aquafeeds due to their high protein and lipid content. However, the limited availability of traditional fish ingredients and the high cost of import pose significant challenges to the aquaculture industry in Africa. In addition, the use of conventional fish feed ingredients has led to water pollution, habitat degradation, and the depletion of fishery resources especially the reliance on fishmeal obtained from wild-caught fish contributes to overfishing and disrupts the marine ecosystem. A variety of alternative raw feed ingredients have shown promise in aquafeeds. These alternatives offer a sustainable source of nutrients and can help reduce the pressure on traditional fish feed ingredients. Some of the potential alternative fish feed ingredients for sustainable aquaculture production in Africa are insect meal (black soldier fly larvae, housefly maggots, mealworms and crickets), animal by-products (leftover parts from the slaughter or processing of animals, such as poultry, cattle, pigs and fish), plant by-products (plant residues from the processing of crops, such as oilseeds, cereals, fruits and vegetables) and algae (photosynthetic microorganisms that can produce various bioactive compounds). Future and emerging trends outlooks in aquafeeds and alternative ingredients have shown that the integration of functional feed additives, such as probiotics and prebiotics, in aquafeeds offers potential health benefits and can enhance the performance and resilience of farmed species. Also, the adoption of circular economy principles in aquafeed production using agro-industrial by-products aims to minimize waste and maximize resource efficiency. Continued genetic advancements in aquaculture species, combined with customized feed formulations, can lead to enhanced growth rates, feed conversion efficiency, and disease resistance. Meanwhile, research efforts have shown that other non-conventional protein sources such as agricultural wastes and byproducts hold enormous potential in future fish feed formulations (table 1).
The alternative feed ingredients offer greater opportunity for sustainable aquaculture production in Africa as these can improve the resilience and sustainability of aquafeed production, decreasing reliance on scarce resources. Also, it creates opportunities for the aquaculture industry to emphasize their commitment to environmentally friendly practices through the utilization of alternative raw ingredients.
However, the alternative fish feed ingredients utilization in aquafeed are faced with the challenges of ensuring the cost-effectiveness and scalability of alternative raw ingredients. More research and innovations in ingredient production and processing can help in addressing these concerns and facilitate market adoption. Furthermore, the development of clear regulations and standardized criteria for alternative raw ingredients in aquafeeds is essential to ensure quality control, safety, and integrity in the production and marketing of aquaculture products.
More research and innovation are, however. needed to overcome these challenges and unlock the full potential of alternative feed ingredients as a sustainable and circular solution for aquaculture production. Further research is needed to optimize the processing methods, formulation strategies and feeding practices of these alternative feed ingredients for different fish species and culture systems. In conclusion, these alternative fish feed ingredients can reduce the dependence on imported feed ingredients, lower the cost of production, improve the nutritional quality of fish and enhance the environmental and social sustainability of aquaculture in Africa.