Investigation of the effect of phytogenic supplementation and probiotics on growth performance and immune parameters in channel catfish and shrimp.

Abstract

In recent decades, aquaculture has become leading contributors to global food supply and help economic development. However, disease outbreaks remain a serious challenge, leading to billions of dollars in losses each year. Bacterial infections such as Aeromonas hydrophila in fish and Vibrio parahaemolyticus in shrimp are among the most significant causes of mortality in production systems. The heavy use of antibiotics to manage these diseases has raised major concerns about antimicrobial resistance and environmental impacts, creating a need for safer, feed- based alternatives like phytogenic and probiotics. The first part of this study focused on phytogenic feed additives (Actifor Pro, Actifor Power, Fresta Protect, Syrena Boost, and Enviro QS) and their effects on the growth performances, immunity, and disease resistance ageist Aeromonas hydrophila of juvenile channel catfish (Ictalurus punctatus). Although growth performance did not differ among treatments, fish fed phytogenic diets Fresta protect (FP) showed better survival after A. hydrophila challenge and higher serum lysozyme activity. The second experiment evaluated Bacillus spp. Probiotics doses in Pacific white shrimp (Litopenaeus vannamei) reared in biofloc conditions. While growth parameters such as final biomass, survival, and feed conversion ratio were not significantly different among treatments probiotic-treated shrimp displayed improved survival following V. parahaemolyticus challenge and moderate changes in gut microbiota diversity. Immune parameters, such as total hemocyte count (THC), did not differ. Interestingly, the expression of the antioxidant gene in the shrimp gut was significantly downregulated. Together, these results suggest that phytogenic and probiotics can enhance disease resistance and overall health, offering practical, eco-friendly alternatives to antibiotics in aquaculture.