Entropy weight-based optimization of Antarctic krill meal inclusion for juvenile Chinese mitten crabs: Balancing growth performance, health, feeding behavior and feed cost

Developing cost-effective feeds that enhance palatability, growth, and overall health is crucial for the sustainable culture of Chinese mitten crabs (Eriocheir sinensis). Antarctic krill meal (AKM), rich in nutrients and feed-promoting substances, is a potential feed ingredient. This study evaluated the effects of AKM inclusion on juvenile Chinese mitten crabs based on feeding behavior, growth performance, feed utilization, nutrient deposition, and antioxidant and immune responses. Five diets with graded levels of AKM (0, 1.5 %, 3 %, 4.5 % and 6 %) were fed to juvenile crabs over two completed molting intervals. The results showed that: (1) AKM inclusion significantly increased the feeding intake rate and decreased the first eating and exploration time of juvenile crabs, with no significant differences observed in groups with 3 % or higher AKM content; (2) final body weight (FBW) and weight gain (WG) increased significantly, while the feed conversion rate (FCR) decreased significantly with increasing AKM level; (3) the crude lipid and ash contents in the body rose significantly with AKM inclusion; (4) AKM enhanced glutathione peroxidase activity and hemocyanin content, while hemolymph alkaline/acid phosphatase activities peaked at 3 % AKM; (5) under non-ionic ammonia stress, the survival rate was significantly higher in AKM-supplemented groups. In conclusion, based on a comprehensive evaluation using the entropy weight method, the optimal AKM inclusion level is 3 % for juvenile Chinese mitten crabs, enhancing feed palatability, growth, and health conditions.