Alternative Proteins for Fish Diets: Implications beyond Growth

Abstract

Aquaculture has been challenged to find alternative ingredients to develop innovative feed formulations that foster a sustainable future growth. Given the most recent trends in fish feed formulation on the use of alternative protein sources to decrease the dependency of fishmeal, it is fundamental to evaluate the implications of this new paradigm for fish health and welfare. This work intends to comprehensively review the impacts of alternative and novel dietary protein sources on fish gut microbiota and health, stress and immune responses, disease resistance, and antioxidant capacity. The research results indicate that alternative protein sources, such as terrestrial plant proteins, rendered animal by-products, insect meals, micro- and macroalgae, and single cell proteins (e.g., yeasts), may negatively impact gut microbiota and health, thus affecting immune and stress responses. Nevertheless, some of the novel protein sources, such as insects and algae meals, have functional properties and may exert an immunostimulatory activity. Further research on the effects of novel protein sources, beyond growth, is clearly needed. The information gathered here is of utmost importance, in order to develop innovative diets that guarantee the production of healthy fish with high quality standards and optimised welfare conditions, thus contributing to a sustainable growth of the aquaculture industry.

Agouti-related protein as the glucose signaling sensor in the central melanocortin circuits in regulating fish food intake

“…Feeding carbohydrate or plant protein feed added to carnivorous fish often induces feeding inhibition, resulting in a significant decrease in the feeding rate, thereby reducing growth performance ( 92 , 93 ). Our lab has been researching aquatic feed for over 10 years ( 94 , 95 ).…”

“…In order to solve this basic research topic of industrial and fish feed applications, a series of research on plant protein replacement has been performed regarding aquatic nutrition. This area has made significant progress, making it one of the most important and actively researched fields concerning aquatic nutrition and metabolic regulation ( 93 , 98 – 102 ). Scientists have tried to answer the questions surrounding feeding inhibition and nutrient metabolism disorders of carnivorous fish after replacing fish meal with plant protein by studying the raw ingredients of plant protein (amino acid pattern, carbohydrates, anti-nutritional factors), fish nutrition sensors, and fish nutrition response effectors ( 103 ).…”

Growth and Welfare of Rainbow Trout (Oncorhynchus mykiss) in Response to Graded Levels of Insect and Poultry By-Product Meals in Fishmeal-Free Diets

“…Despite its physiological consequences on welfare, stress response has been little investigated in relation to the source of dietary protein in fish. Moreover, the knowledge on the involvement of dietary protein/amino acids in modulating the primary and secondary stress response is still quite unexplored [27,98,99]. Previous studies have shown that plant-based diets induce chronic stress or reduced stress tolerance in rainbow trout [33,100,101], but little or no information is available on the stress response to diets containing insect or poultry by-product meals.…”

Effect of Krill Oil Supplementation and Stocking Density on Growth Performance, Proximate Composition, and Organo-somatic Indices of Cyprinus carpio

“…In fish feeding, the lipids component must meet both energy and essential fatty acid requirements to allow the rapid growth and development required in modern aquaculture production (Sargent et al, 2002;Dong-Kyu Kim et al, 2012). Recently, as a result of the lack of fishmeal and fish oil supplies, new research have been developed to find alternative sources of protein and lipids and to improve the food efficiency, growth, reproduction, health, and physiology of the cultured organisms (Sankian et al, 2019;Aragão et al, 2022).…”