Effect of supplemented Cordyceps militaris extract on disease resistance and survival rate of striped catfish (Pangasius hypophthalmus) fingerlings

The effects of supplemented Cordyceps militaris extract in diets has been studied on the survival and immune response of striped catfish (Pangasius hypophthalmus) fingerlings with bacterial challenge conditions. The experiment was conducted for 60 days with six treatments and three replicates, including negative and positive controls with four dietary supplementation levels of C. militaris extract (0.18%, 0.24%, 0.36%, and 0.47%). After the feeding trial, striped catfish were challenged with Edwardsiella ictaluri at a dose of 10⁵ CFU/mL. Results showed that survival rates of striped catfish increased significantly with higher extract levels, reaching the highest value (70%) at 0.47% supplementation compared with only 16.67% in the positive control group. Hematological indices such as red blood cell (RBC) and white blood cell (WBC) including lymphocytes, monocytes, and neutrophils increased proportionally with extract concentration, which can indicate enhanced immune responses. In conclusion, the findings suggest that dietary supplementation of C. militaris extract at 0.47% improves the disease resistance and health status of striped catfish fingerlings against E. ictaluri infection. This result highlights the potential application of C. militaris extract as a natural immunostimulants to enhance survival and reduce antibiotic use in catfish aquaculture.