The effect of adding duckweed (lemna trisulca) and germinated seeds to juvenile carp (cyprinus carpio L., 1758) diets on growth, body composition, histology, and digestibility

This study investigated the effects of sprouted plant ingredients and Lemna trisulca meal on the growth performance, body composition, tissue histology, and digestibility of common carp (Cyprinus carpio L., 1758). Eight dietary groups were prepared in triplicate: Control, Soybean Sprout, Full-Fat Soybean, Mung Microgreen, Mung Sprout, Wheat Microgreen, Wheat Sprout, and Lemna trisulca. All diets were formulated to be isonitrogenous (40% crude protein) and isolipidic (8% crude fat). The trial was conducted for 90 days in a recirculating aquaculture system using 288 fish with an average initial weight of 5.78±0.2 g. Sprouted plant materials significantly affected growth and physiological parameters (P < 0.05). The Mung Sprout and Mung Microgreen groups achieved the greatest weight gain and specific growth rate, the lowest feed conversion ratio, balanced body protein and lipid levels, and high lipid and satisfactory protein digestibility. No pathological findings were observed in the liver or intestinal tissues of these groups. In contrast, Wheat Sprout, Wheat Microgreen, and Full-Fat Soybean diets resulted in poor growth, poor feed utilization, low protein efficiency ratio, and reduced protein digestibility, accompanied by pathological changes in liver and intestinal tissues. The Lemna trisulca group showed lower growth than the control but exhibited no tissue damage. Overall, mung bean sprout and microgreen meals supported growth performance, digestive function, and tissue health in common carp, whereas wheat-based sprouts and full-fat soybean produced negative effects. Therefore, sprouted mung bean forms can be considered promising alternative ingredients in carp diets