Biochar utilization for aquaculture sustainability: Effect on growth performance, nutrient digestibility, body composition, hematology and mineral status of Ctenopharyngodon idella

Animal health is generally improved by biochar (BC), a promising dietary supplement made from various organic materials including wheat straw, corn cob, home trash, agricultural waste and wood waste. In the current investigation, effects of different BCs inclusion on the growth, digestibility, body composition, hematological indices and mineralization of Ctenopharyngodon idella (6.11±0.02 g; n = 315 fish) fed diets based on sunflower meal (SFM) were investigated over a 60-day period. Seven diets were prepared: first was the control diet i.e., CON and six other diets were supplemented with 2 % different types of BCs, i.e., cotton stick BC (CSBC), wheat straw BC (WSBC), corn cob BC (CCBC), house waste BC (HWBC), grass waste BC (GWBC), and green waste BC (GwBC). A triplicate tank design was employed for each experimental diet, with fifteen fingerlings per tank. Throughout the experimental duration, they were fed 5 % of their live wet weight. The results revealed that CCBC supplementation significantly ( p <0.05) improved the growth, digestibility, and body composition of C. idella , followed by CSBC and WSBC, whereas HWBC showed negative effects. Supplementing with a diet based on 2 % CCBC resulted in the maximum efficiency in mineral absorbance (Cu, Fe, Ca, P, Zn, Ca and K). Moreover, CCBC administration positively impacted all hematological parameters (Hb. PLT, WBCs, RBCs). Conclusively, CCBC was found to be the most efficacious in enhancing the growth, body composition, hematology, nutrient and mineral digestibility of C. idella . • Biochar as supplement improved the health of Ctenopharyngodon idella . • Corncob biochar showed the maximum growth, digestibility and hematology. • House waste biochar negatively affected the health of C. idella .