Protocol for a systematic review of nutritional balancing strategies in low-fishmeal aquafeeds beyond lysine and methionine supplementation

This project documents the protocol information for a PRISMA 2020-based systematic review on nutritional balancing strategies in low-fishmeal aquafeeds. The review focuses on strategies beyond lysine and methionine supplementation, including taurine, essential and functional amino acids, phytase, minerals, vitamins, antioxidants, protein hydrolysates, fermented ingredients, probiotics, yeast-derived products, and gut-health-targeted additives. The purpose of this review is to identify, categorize, and evaluate nutritional strategies that improve growth performance, feed utilization, nutrient digestibility, physiological health, immune and antioxidant responses, gut condition, stress resilience, product quality, and sustainability outcomes in fish, shrimp, and other aquaculture species fed low-fishmeal, fishmeal-free, or high-alternative-protein diets. This OSF registration is intended to improve transparency by documenting the review question, eligibility criteria, search strategy, data extraction plan, quality assessment approach, and narrative synthesis method used in the review.