Impact of Atractylodes lancea Ultrafine Powder on Crucian Carp (Carassius auratus) Growth, Body Composition and Hypoxia Tolerance

The goal of this study is to assess how dietary Atractylodes lancea ultrafine powder (AUP) affects crucian carp (Carassius auratus) growth, body composition, and hypoxia tolerance. A total of 630 crucian carp (13.21 ± 0.17 g) were fed diets containing 0.0%, 3.0%, 6.0%, 9.0%, 12.0%, 15.0%, and 18.0% AUP for 15 days. In crucian carp, dietary AUP was observed to improve protein content and decrease weight gain and fat content (p < 0.05). The ideal AUP addition level for fish was 13.04%, based on broken-line regression analysis of the protein concentration in fish bodies. The tissues and organs of crucian carp showed increased enzymatic antioxidant activities and non-enzymatic antioxidant levels, indicating that dietary AUP reduced the production of reactive oxygen species (ROS) and inhibited lipid oxidation (p < 0.05). This study shows that dietary AUP has a significant anti-obesity impact in fish, which is strongly linked to boosting the anabolism of protein and antioxidant defense as well as improving glucose metabolism to reduce glucose as the raw material for body fat synthesis. Additionally, under hypoxic conditions, the addition of AUP increased duration time (DT) and decreased crucian carp oxygen consumption rate (p < 0.05). The DT broken-line regression study verified that 6.05% is the ideal AUP level for fish. According to our research, dietary AUP strengthens fish’s resistance to hypoxia by modifying the metabolism of proteins and carbohydrates for energy production and enhancing antioxidant defense in respiration-related tissues and organs. In conclusion, AUP may be a natural way to reduce fish obesity and hypoxic stress.