Survival, immune response and growth of Penaeid shrimp as affected by immunostimulants: A meta-analysis

Immunostimulants represent the most innovative approach for combating shrimp diseases. They are molecules that effectively enhance the host's nonspecific defenses against invading microorganisms. However, methodological differences exist among immunostimulants based on the same source. Therefore, conducting a meta-analysis is essential to derive valid conclusions. The effect size value utilized in this study was Hedges' d. Heterogeneity among studies was assessed using the DerSimonian and Laird tests (Q-statistic). Meta-regression analysis was conducted to explore the sources of heterogeneity in treatment effects. In this study, dose served as a covariate because it was the only continuous variable that significantly contributed to the observed heterogeneity. Funnel plots and the fail-safe number were employed to assess publication bias within the datasets. The article collection process followed the PRISMA methodology. Based on the results of the meta-analysis and meta-regression conducted with 83 articles, it can be concluded that immunostimulants have a significant effect, characterized by high category standard mean difference (SMD) values, on the survival, growth, and immune response of Penaeid family shrimp. Among potential immunostimulants options, algae ingredients exhibited the most favorable effects on the survival, growth, and immune response of Penaeid family shrimp. Subgroup analysis outcomes revealed that various extraction methods significantly impacted the efficacy of immunostimulants, with the ethanol solvent method proving to be the most effective. Among different administration methods, no significant effect was observed on immunostimulant efficacy across all parameters, with positive SMD values for all administration methods. Regarding challenged test pathogens, immunostimulants were observed to enhance immune response, survival, and weight gain against various pathogens. Meta-regression results indicated that algal treatments had a lower optimal dose point, leading to decreased efficacy as the dose increased. In contrast, fungi exhibited a higher optimum dose point, resulting in increased efficacy at higher doses.