Effect of dietary supplemented andrographolide on growth, non-specific immune parameters and resistance against Aeromonas hydrophila in Labeo rohita (Hamilton)

• Andrographolide supplemented diet showed improved growth performance of Labeo rohita.
• An immunomodulatory effect of andrographolide has been pragmatic in L. rohita.
• 0.1% of andrographolide supplemented diet showed higher RPS against Aeromonas hydrophila.
• Andrographolide would act as potential herbal immunostimulant.

The present study evaluated the effect of dietary andrographolide (EC 50%) on growth, non-specific immune parameters and disease resistance against Aeromonas hydrophila infection in Indian major carp, Labeo rohita fingerlings. Fishes were fed with formulated diet containing andrographolide as T0 (0.00%), T1 (0.05%), T2 (0.10%), T3 (0.20%), T4 (0.40%) and T5 (0.80%) for 42 days. Fishes were challenged with A. hydrophila 42 days post feeding and relative percentage survival (RPS) was recorded over 14 days post challenge. Blood and serum samples were collected for nonspecific immune parameters on 14, 28 and 42 days of feeding and growth performance was evaluated at the end of experiment. The results revealed that fishes fed with andrographolide showed significant (p < 0.05) increase in NBT levels, myeloperoxidase activity, phagocytic activity, serum lysozyme activity, and serum antiprotease activity when compared to the control group. The weight gain, specific growth rate, feed conversion ratio and protein efficiency ratio of fishes fed with andrographolide were found to be significantly (p < 0.05) differed compared with control. Dietary andrographolide at the level of 0.10% showed significantly (P < 0.05) higher RPS (74.06%) against A. hydrophila infection than control. The results revealed that andrographolide supplemented diet has a stimulatory effect on non-specific immune parameters along with improved growth performance and increased disease resistance against A. hydrophila infection in L. rohita fingerlings.