Dietary tea polyphenol supplementation and its impacts on growth performance, plasma parameters, and antioxidant capacity of juvenile genetically improved farmed tilapia (GIFT: Oreochromis niloticus)

The term ‘tea polyphenols’ (TPs) comprises a broad range of polyphenol compounds present in tea, demonstrating positive health effects such as antioxidant activity, etc. in animals. This study investigated the effects of TPs supplementation in juvenile genetically improved farmed tilapia (GIFT); Oreochromis niloticus). Fifteen fish (weight: 13.46 ± 1.25 g) were distributed in six tanks and randomly assigned with diets containing graded levels of TPs (mg/kg): 0.00 (control), 100, 200, 300, 400 and 500 in quadruplicate for 8 weeks. After the trial, the fish fed 500 mg/kg TPs exhibited a significant reduction (p < 0.05) in final body weight (FBW) compared with the control. Whole-body moisture content was elevated, while crude protein was lowered significantly (p < 0.05) by a 100 mg/kg TPs diet compared with the control. Plasma low-density lipoprotein (LDL) was significantly elevated (p < 0.05) at over 200 mg/kg; triglyceride (TG) content was lowered (p < 0.05) by the TPs diet compared with the control diet. Catalase (CAT) was significantly enhanced (p < 0.05) by TPs except at 300 mg/kg; superoxide dismutase (SOD) was increased (p < 0.05) by 200, 400 and 500 mg/kg; total antioxidant capacity (T-AOC) was enhanced (p < 0.05) by 400–500 mg/kg; glutathione (GSH) was improved (p < 0.05) by 500 mg/kg; and malondialdehyde (MDA) level was elevated (p < 0.05) in the 100–200 mg/kg TPs diet compared with the control. TPs can be utilized as a feed supplement to improve the plasma biochemical parameters and AOC of GIFT juveniles.