Dietary Supplementation With White and Common Turmeric Improves Resistance to <scp><i>Argulus siamensis</i></scp> in <scp><i>Labeo rohita</i></scp>

This study evaluated white turmeric (Curcuma zedoaria) as a sustainable feed additive alternative to common turmeric (C. longa) for enhancing disease resistance in Labeo rohita against Argulus siamensis infection. Juvenile L. rohita (15.8 ± 1.9 g) were divided into four treatment groups (n = 60 per group): (1) Control (commercial feed), (2) common turmeric-supplemented feed (1% w/w), (3) white turmeric-supplemented feed (1% w/w), and (4) combined turmeric-supplemented feed (0.5% common +0.5% white turmeric). Fish were fed experimental diets for 45 days before challenge with A. siamensis (10 parasites/fish), followed by 15 days of post-challenge monitoring (total experimental period: 60 days). Samples were collected on days 0, 15, 30, and 45 of the feeding phase, and on days 7 and 15 of the post-challenge phase. Results showed that turmeric supplementation significantly enhanced growth performance, haematological parameters (RBC, haemoglobin, haematocrit), immunological responses (lysozyme, respiratory burst, complement activities), and antioxidant status (SOD, CAT, MDA) compared to control. Post-challenge, turmeric-supplemented groups exhibited reduced parasite load and higher survival rates (Combined: 92%, common turmeric: 85%, White turmeric: 82%, Control: 68%). While common turmeric performed slightly better than white turmeric when used alone, the combined treatment showed superior efficacy in all parameters measured. These findings suggest that combining both turmeric species provides optimal benefits, while white turmeric can serve as a partial substitute for common turmeric in fish feed formulations when resource sustainability is a priority, thus helping to reduce competition with human food resources.