Fish and fishery products are a significant source of protein and critical micronutrients needed for optimal health. Diseases and diverse parasite diseases cause significant losses to the aquaculture sector. Immunostimulation is an effective method for preventing infectious diseases in the sector. The use of herbal compounds as immunostimulants in aquaculture is fast growing to circumvent the usage of harmful antibiotics. Rohu (1.9±0.08g) were cultured in 3m2 hapa under three different feeding regimes with three replicate of each treatment in the pond of ICAR-CIFE center Rohtak, Haryana. The feeding diets were seeds (0.5%) and leaves (0.5%) of Achyranthes aspera and diet without plant ingredients served as control. After 60 days of feeding fish were challenged with virulent Aeromonas hydrophila bacteria (5x106 cells/ml). The mortality was observed after 7 days; more mortality found in control fed then rest of the treatments. The major water quality parameters like temperature, pH, dissolved oxygen and conductivity were recorded regularly using HQ40d Multiparameter (Hach, USA) from four sides of the pond closer to the hapas. Water temperature and pH ranged from 28.5 to 31°C and 8.4 to 9.16, respectively throughout the culture period. Dissolved oxygen level ranged from 7.11 to 9.62 mg/L in the pond. Average weight, MPO and NOS levels were significantly higher in plant supplemented diets fed rohu compared to control group. TBARS and carbonyl protein concentrations were decreased in the experimental groups compare to the control group. The mRNA expression of immunological genes (Lysozyme C, Lysozyme G, TNF-α, IL-10, IL-1β and TLR-4) also showed the positive results in the treatment diets. It showed that, the diets with plant ingredients increase the immunity in rohu in pond culture system.
Keywords: Achyranthes aspera, Labeo rohita, Immunostimulation, Disease resistant property, Field conditions