Combined effects of butyl hydroxytoluene and vitamin C on the growth performance, blood biochemistry, and antioxidative status of common carp (Cyprinus carpio)

Common carp are proper finfish species for intensification, though their feeds should be reinforced with functional additives to ensure high growth performance and health status. Thus, this study tested the combined effects of butyl hydroxytoluene (BHT) and vitamin C (VC) on the growth performance, blood biomarkers, and antioxidative capacity of common carp. Fish were allotted into four groups and fed on four diets where the control diet was free of VC or/and BHT, while the second and third diets contained dietary VC or BHT at 500 or 150 mg/kg, respectively. The fourth diet was supplemented with both VC (500 mg/kg) and BHT (150 mg/kg) (BHT+VC). After 70 days, feeding VC or/and BHT markedly affected the growth performance of common carp. Carps fed VC, BHT, or BHT+VC had higher (P<0.05) FBW, WG, and SGR than fish fed the control diet, while the FCR was lower (P<0.05) in fish fed both VC and BHT than the control. In addition, feeding BHT or both BHT+VC markedly (P<0.05) reduced the AST, ALT, and urea. The blood protein, albumin, and globulin were higher (P<0.05) in fish-fed VC or/and BHT than in the control. Fish fed dietary VC, or BHT+VC, had lower (P<0.05) total cholesterol (T-CHO) and triglycerides (TG) than those fed on the control or BHT. The SOD, CAT, and GPX were significantly higher (P<0.05) in carp fed on dietary VC or/and BHT than in fish fed on the control diet. Nevertheless, the malondialdehyde level was lower (P<0.05) in carp fed on VC or BHT+VC diets than fish on the control or BHT diets. The lysozyme activity was significantly higher (P<0.05) in carp fed on the BHT+VC diet than in the control or VC. In conclusion, the study suggests that dietary BHT or/and VC can be added to the diets of common carp to enhance the growth performance, feed digestion, blood biomarkers, and antioxidative capacity.