Advances in the replacement of fishmeal with terrestrial plant proteins in aquaculture feeds

Background China’s aquaculture production continues to grow, driving rising demand for formulated aquafeeds. Fish meal, valued for its balanced amino acids and palatability, faces supply constraints from overfishing and climate variability, limiting production expansion and failing to meet the need for premium protein. In contrast, terrestrial plant proteins—soybean meal, rapeseed meal, cottonseed meal, peanut meal, and corn gluten meal—are abundant and show great promise as fish meal substitutes in aquafeeds.

Analysis This paper reviews current research on terrestrial plant proteins in aquaculture. It compares amino acid profiles of major plant sources with fish meal, emphasizing differences in lysine, methionine, and threonine. It also examines the effects of replacing fish meal with these proteins on growth, immunity, and intestinal health in farmed aquatic animals. Major limitations include anti-nutritional factors (trypsin inhibitors, glucosinolates, gossypol, aflatoxins), amino acid imbalances, and reduced palatability. Improvement strategies—fermentation, enzymatic hydrolysis, chemical modification, and extrusion—are evaluated for their advantages and disadvantages, aiming to provide theoretical support for feed formulation optimization and industrial application.

Progress Replacement potential varies by plant source and aquatic species, depending on amino acid profile and anti-nutritional factor levels. Maximum recommended replacement levels are approximately 40%–60% for soybean meal, 20% for corn gluten meal, 20%–30% for peanut meal, 20% for rapeseed meal, and 20% for cottonseed meal, though these values require species-specific adjustments. Processing techniques such as fermentation and enzymatic hydrolysis degrade heat-labile anti-nutritional factors and improve digestibility; chemical modification and extrusion further reduce harmful components and enhance nutritional value. Collectively, these methods effectively lower anti-nutritional factors, increase feed intake, and improve growth performance in several aquaculture species.

Prospect In summary, terrestrial plant proteins are viable alternatives to fish meal in formulated feeds, significantly reducing production costs and easing pressure on fish meal supplies. However, challenges persist, including low digestibility and endogenous anti-nutritional factors that may harm liver and intestinal health. Future research should focus on cost-effective technologies to remove anti-nutritional factors and improve processing to boost protein utilization. Additionally, optimized nutritional strategies—supplementing limiting amino acids and using functional additives (probiotics, organic acids, enzymes)—should be explored to mitigate adverse effects on animal health. Establishing a comprehensive technical system for plant protein replacement is essential to achieve a stable, high-quality, and sustainable protein supply for the aquaculture feed industry, supporting its long-term development.