Withania coagulans root powder effect on growth, hematology, digestive enzyme activity, antioxidant status, serum immune response, and tolerance against Aeromonas hydrophila in Common Carp

Objective The use of plant‐derived products in aquaculture has garnered considerable attention due to their potential benefits. This study investigated the impact of supplementing Withania coagulans root powder (WCRP) in the diet of Common Carp Cyprinus carpio on various parameters, including growth performance, digestive enzymes, hematology, antioxidant activity, and immunological aspects. Methods Common Carp (mean weight ± standard deviation = 11.69 ± 0.48 g) were divided into four groups in triplicate, receiving different WCRP concentrations (0.0, 1.0, 1.5, and 2.0%; labeled as WCRP0, WCRP1.0, WCRP1.5, and WCRP2.0, respectively) over a 60‐day period, followed by an experimental challenge with Aeromonas hydrophila to assess the relative percentage survival (RPS) over 14 days. Result Results showed that Common Carp receiving WCRP1.5 and WCRP2.0 demonstrated significantly improved growth performance, with reduced feed conversion ratios (FCRs) being particularly evident in WCRP1.5. Polynomial contrasts indicated significant linear and quadratic effects on weight gain and FCR. Additionally, WCRP1.5 and WCRP2.0 supplementation led to significantly higher activity of digestive enzymes (lipase and protease). Hematological parameters, including white blood cells, red blood cells, hemoglobin, and hematocrit, were significantly elevated in fish that were fed WCRP1.5 and WCRP2.0 compared to the control group. Moreover, serum parameters, such as total protein, albumin, globulin, lysozyme, catalase, superoxide dismutase, and total immunoglobulins, were significantly enhanced in WCRP1.5‐ and WCRP2.0‐treated fish. Notably, the WCRP1.5 group showed the lowest serum cortisol levels. The RPS was highest in WCRP1.5 (73.77%), followed by WCRP2.0 (70.43%), compared to the other groups. Conclusion In conclusion, supplementation with WCRP1.5 and WCRP2.0 effectively improved both growth and health parameters in Common Carp. Impact Statement The addition of Withania coagulans root powder (WCRP) to Common Carp diets significantly boosted growth, health, and disease resistance. Fish that were fed medium and high doses of WCRP showed better growth, improved blood health, and enhanced immune responses, leading to higher survival rates after a bacterial challenge. This natural supplement offers a cost‐effective way for farmers to improve fish productivity and resilience.