Effect of fish waste hydrolysate on growth performance and health status of milk fish (Chanos chanos) and its potential to reduce feed

Abstract

The study was undertaken to unravel the potential of fish waste hydrolysate (FWH) on enhancing phytoplankton production and reducing formulated feed in milkfish (Chanos chanos) culture. Milkfish fry (Average Body Weight (ABW): 0.137 ± 0.004 g) were randomly distributed in 27 Fiber Reinforced Plastic (FRP) tanks with 20 fry per tank. The experiment was conducted with three levels of FWH supplementation (0, 20 and 40 ppm) and three levels of feed supplementation (0, 50 and 100%). The FWH supplementation at 40 ppm significantly (p < 0.01) improved the average daily gain (ADG), total biomass gain and survival (%) of C. chanos. Further, the FWH supplementation at 40 ppm with 50% feed reduction showed similar ADG, specific growth rate (SGR), biomass gain in C. chanos compared with group received 100% feed without FWH. The FWH supplementation significantly (p < 0.01) increased the microalgae diversity and abundance compared to other treatments and has positive correlation with the enhanced growth performances of fish. The gut microbial study showed that 40 ppm of FWH significantly (p < 0.01) increased total bacterial load but inhibited Vibrio population. The FWH supplementation improved haematological parameters signifying better health status of C. chanos. Healthy histopathology of liver of C. chanos supplemented with FWH and fed with 50% feed also supported the effect of FWH on the enhancement of health status of C. chanos. It can be concluded that FWH supplementation at 40 ppm can save 50% of required feed without affecting growth performance and survival of C. chanos.