Effect of jaggery based biofloc meal supplementation on growth, digestive enzymes and disease resistance in Penaeus vannamei in recirculatory aquaculture system

A 60 days experiment was conducted to evaluate the effect of jaggery based biofloc meal on growth performance, digestive enzymes activities and resistance against Vibrio parahaemolyticus in Penaeus vannamei in Recirculatory Aquaculture System (RAS). The biofloc was prepared using jaggery as carbon source at 20:1 C/N ratio in outdoor biofloc development tanks, graded and powdered to use for dietary inclusion levels viz., 5 (T1), 10 (T2), 15 (T3), 20% (T4). P. vannamei with an average body weight of 0.58±0.4g were stocked with stocking density of 200 /m³ in indoor RAS (5×3=15) tanks (Length×Breadth× Height: 1×1×1 m) in triplicate following a completely randomized design. Among the treatment groups, 15% biofloc powder supplementation showed the highest mean weigh gain, SGR, FER, PER and lowest FCR followed in T4. The treated groups exhibited an enhanced amylase, protease, and lipase activity compared to control. Moreover, 15% biofloc powder supplementation (T3) showed significantly higher resistance against V. parahaemolyticus with high survival rate as compared to other groups. The hepatopancreas of T3 group showed high number of B and R cells with healthy lumen followed by T4, and T2 whereas, the control lacked B and R cells, degeneration of tubule lumen and hemocytic infiltration. The study confirmed that the inclusion of jaggery based biofloc meal at 15% level in shrimp feed could enhance the growth performance, survival rate, digestive enzymes and resistance against pathogenic bacterial infection activity in RAS based system.