Comparative Effects of Herbal Extracts on Growth Performance and Nutritional Quality of Freshwater Prawn (Macrobrachium rosenbergii) in Biofloc System

The freshwater prawn (Macrobrachium rosenbergii) constitutes an integral component of the aquaculture sector in Bangladesh, with biofloc technology (BFT) emerging as a sustainable and resource-efficient alternative to conventional farming methods. This study evaluated the comparative effects of three herbal extracts—ginger (GE), amla (AE), and garlic (GaE)—on the growth performance, survival rate, and nutritional composition of M. rosenbergii juveniles cultivated in a biofloc-based system over an eight-week period. Four experimental groups were established: a control (T1), GE (T2), AE (T3), and GaE (T4), with herbal extracts incorporated into commercial feed at a concentration of 200ml/ kg. Among the treatments, amla extract (T3) yielded the most favorable results, reflected in significantly higher mean weight gain (10.5 ± 0.5 g), percentage weight gain (275.5 ± 27.7%), and specific growth rate (2.6 ± 0.1%). The feed conversion ratio (FCR) was the lowest in T3 (0.8 ± 0.0), indicating superior feed efficiency. Proximate analysis of muscle tissue revealed that prawns in the AE group had the highest crude protein content (74.1%) along with optimal fat and fiber levels, highlighting its nutritional benefits. Additionally, the presence of biofloc improved water quality and performance metrics across all treatments compared to the control. These findings suggest that integrating amla extract with BFT can significantly enhance growth, feed utilization, and flesh quality in prawn aquaculture, offering an environmentally sustainable and economically viable strategy.