Laligurans (Rhododendron arboreum) Enhances Growth, Enzyme Profiles, and Immune Response of Grass Carp Ctenopharyngodon idella (Val. 1844)

Abstract

This study evaluates the effects of Laligurans (Rhododendron arboreum) flowers on the growth performance and health parameters of grass carp (Ctenopharyngodon idella). Known for their anti-inflammatory properties and medicinal uses, Laligurans flowers were incorporated into diets as an ethanol extract (LGE) and fine powder (LGP) to test their efficacy. A total of 630 grass carp fingerlings (3.07 ± 0.76 g to 3.95 ± 0.85 g) were randomly distributed into 21 nylon cages (1.5 m × 1 m × 2 m) placed in an earthen pond. Seven dietary treatments were administered: a control diet (T1) with standard commercial feed, LGE-supplemented diets (T2, T3, T4, and T5) at 0.20%, 0.40%, 0.80%, and 1.60% inclusion levels, respectively, and LGP-supplemented diets (T6 and T7) at 0.20% and 0.40%, respectively. Results demonstrated significant improvements (p < 0.05) in liver, kidney, and blood serum protein levels (total protein, albumin, globulin, and AG ratios) in treated groups compared to the control. Reductions in SGOT, SGPT, and ALP levels were observed in the liver and blood serum of treated groups, while control fish exhibited elevated blood urea nitrogen and creatinine. Fish fed LGE diets showed superior blood profiles compared to those receiving LGP. The T4 group (0.80% LGE) achieved the highest final weight gain, specific growth rate, and survival rate (p < 0.05), highlighting the potential of Laligurans flower extract as a natural immunological and growth-enhancing supplement in aquaculture diets.