Application of fermentation strategy in aquafeed for sustainable aquaculture

Because of its high nutritional value, palatability and increased digestibility, fishy meal is widely used as an animal protein source in the aquafeed industry. However, the resource shortages and rising prices seriously restrict the use of fish meal (FM) in aquaculture. In this light, much efforts have been conducted to seek the sustainable supplies of protein sources to substitute FM. Due to their relatively low protein content and palatability, the presence of anti-nutritional factors (ANFs) and unbalanced amino acid profiles, the plant protein sources have been limited in aquafeed, whereas the animal protein sources can replace FM in aquafeed due to their high protein content, total digestible dry matter and lack of ANFs. The fermentation process was recognized for its role in improving the nutritional quality of animal and plant protein sources. The protein sources can be treated with appropriate microorganisms to preserve its nutrients and finally incorporated into aquafeed, which would reduce feed costs and environmental pollution. Fermented meals showed better nutrient efficiency and could improve the nutritional value of aquafeed. This review was intended to present more updated information about the application of fermented ingredients in aquafeed industry. Based on the data collected, this review will contribute to further research into the production of fermented feed as a functional feed for sustainable aquaculture.