Effects of Heterologous Protein Substitutions of Fishmeal on the Culture of the Chinese Soft-Shelled Turtle (Pelodiscus sinensis): A Review and Meta-Analysis

With the global aquaculture industry growing rapidly, fishmeal (FM) occupies an important position in aquatic animal nutrition as a traditional feed ingredient, but its production is facing rising costs and sustainability challenges, making the search for high-quality heterologous proteins particularly essential. The effects of different protein substitutes for FM in the diets of Chinese soft-shelled turtles (Pelodiscus sinensis) have been evaluated through a review and meta-analysis, focusing on their impact on the growth performance, immune response, and health status of the turtles. This meta-analysis evaluates the effects of heterologous protein substitutions for FM in the diet of Chinese soft-shelled turtles (Pelodiscus sinensis). A total of 10 studies with 37 independent datasets were included, revealing that FM significantly outperforms all alternatives in promoting weight gain (β = 12.18, 95% CI [7.77, 16.58], p  < 0.001). Despite the nutritional potential of heterologous proteins, a dose–response reversal phenomenon was observed at higher inclusion levels. These findings underscore the importance of optimizing protein substitution ratios for sustainable aquaculture practices.