Study of various curcumin-dietary feeding regimens on growth performance, non-specific immunity, and <i>Aeromonas hydrophila</i> resistance in juvenile common carp ( <i>Cyprinus carpio</i> )

This study investigated the impact of various curcumin feeding regimens on growth, innate immunity, and disease resistance against Aeromonas hydrophila in juvenile common carp ( Cyprinus carpio ) (initial weight: 6.35 ± 0.022 g). Fish were reared in a recirculating system for 8 weeks and divided into five groups: one control group (Regimen 1, R1) receiving the basal diet, the three intermittent feeding groups were fed a trial diet of 60 mg curcumin kg-1 for one week (Regimen 2, R2), two weeks (Regimen 3, R3), and four weeks (Regimen 4, R4), respectively, followed by feeding with the basal diet for equivalent durations, repeating this cycle for the 8-week experimental duration, and one continuous feeding group (Regimen 5, R5) receiving the trial diet. The four-week pulsed regimen (R4) significantly improved weight gain rate compared to other groups (P &lt; 0.05), though survival and feed conversion ratio remained unchanged. Immune and antioxidant parameters, including white blood cell count (WBC), respiratory burst, superoxide dismutase (SOD), myeloperoxidase (MPO), and tumor necrosis factor-α (TNF-α) activity, which peaked under R4 before declining in R5. Transaminase levels (AST and ALT) were elevated in R2 and R4 but did not differ among treatment groups. In challenge tests with A. hydrophila , the R4 and R5 groups showed significantly reduced cumulative mortality compared to controls. These results indicate that a four-week intermittent curcumin regimen optimally enhances growth and immunity while supporting practical and economic aquaculture applications for C. carpio .