Comparative Impacts of Plant-Derived Functional Diets (Azolla, Duckweed, and Napier Grass) on Growth, Hematology, and Serum Biochemistry of Grass Carp (Ctenopharyngodon Idella)

This study assesses the effects of partial dietary replacement with three plant-based ingredients, Azolla (Azolla pinnata), Duckweed (Lemna minor), and Napier grass (Pennisetum purpureum), on growth performance, hematological indices, and serum biochemical parameters in grass carp (Ctenopharyngodon idella). A 60-day feeding trial was conducted using 240 juvenile fish (initial weight 14.38 ± 0.12 g) randomly distributed into four dietary groups: a control (T0) and three experimental diets containing 10% Azolla (T1), Duckweed (T2), or Napier grass (T3). Each treatment was replicated three times. Growth parameters, feed utilization, hematological profiles, and serum biomarkers were assessed post-trial. Results indicated that the T2 (Duckweed) group exhibited significantly superior final body weight (58.1 ± 1.4 g), weight gain (43.8 ± 1.5 g), specific growth rate (2.757 ± 0.044 % day⁻¹), feed conversion ratio (2.171 ± 0.035), and protein efficiency ratio (1.531 ± 0.032) compared to the control and other treatments (P< 0.05). Hematological analysis revealed significantly elevated red and white blood cell counts, hemoglobin, and hematocrit values in the T2 group. Serum biochemical profiles indicated higher total protein, albumin, and globulin levels, along with reduced glucose, cholesterol, triglycerides, and hepatic enzyme activities (AST, ALT, and ALP) in Duckweed-fed fish. Azolla supplementation yielded intermediate results, while Napier grass led to the poorest performance across all parameters. The study concludes that Duckweed at 10% inclusion is a highly effective, sustainable feed ingredient for enhancing growth and health in grass carp aquaculture, whereas Napier grass is less suitable as a primary dietary component.