Dietary biochar effect on growth performance, proximate composition, and physiological response of Penaeus vannamei (Boone, 1931) cultured in inland saline groundwater

Transforming raw materials (biomass feedstock) into biochar finds diverse applications across various industries owing to the distinctive characteristics of biochar. This study used biochar as a feed additive for shrimp feeding. A 90-day feeding trial was conducted to assess the impacts of different biochars on growth parameters, haematological parameters, and digestive enzymes of Penaeus vannamei reared in inland saline groundwater of 10 ppt salinity. The finely ground biochar (0.5 mm) prepared from different sources was mixed with the commercially available shrimp feed (35 % crude protein, 5 % crude fat, and 4 % crude fibre), viz., T1, paddy straw biochar (PSB); T2, sugarcane bagasse biochar (SBB); T3, banana peduncle biochar (BPB); and the control group (C) without any biochar. Twenty shrimp (10.24 +/- 0.01 g) were stocked in each triplicate. Banana peduncle biochar incorporated diet (T3) demonstrated superior performance as it significantly (p<0.05) improved the weight gain (24.51 +/- 0.12 g), specific growth rate (1.39 +/- 0.00 % day(-1)), protein efficiency ratio (1.73 +/- 0.02 %), and reduced feed conversion ratio (1.60 +/- 0.01). The total serum protein in the haemolymph of the shrimps for all the dietary biochar treatments differed significantly (p<0.05) from the control. The T1, T2, and T3 groups showed the highest whole-body crude protein content; contrary to this, the lowest amount of whole-body crude protein was observed in the control. In addition, the dietary biochar significantly influenced the digestive enzymatic activity of shrimp. The hepatopancreatic AST and ALT activities of different biochar-fed groups were significantly (p < 0.05) higher than the C group. On the other hand, dietary biochar treatments did not significantly (p > 0.05) influence the SOD of the gill, muscle, and catalase activity of the hepatopancreas, gill, and muscle in shrimp. Overall, the three different dietary biochar supplementations in the diet of Penaeus vannamei seem to be an effective way to culture it intensively, in addition to significantly reducing various stress responses.