Comparative Evaluation of Indigenous Medicinal Plants as Phytogenic Feed Additives in Soybean Meal-Based Diets: Effects on Growth Performance, Haematological Responses in Labeo rohita

Abstract

Aims: This study comparatively evaluated the effects of indigenous medicinal plants incorporated as phytogenic feed additives in soybean meal-based diets on growth performance, haematological responses, serum biochemical parameters, and antioxidant status in Labeo rohita and sought to identify the most effective phytogenic dietary formulation for sustainable freshwater aquaculture. Study Design: A completely randomised design (CRD) comprising seven dietary treatments, with three replicates per treatment. Place and Duration of Study: The study was conducted in Nanded and Latur, Maharashtra, India, between January and April 2025. Methodology: Healthy Labeo rohita fingerlings (18–22 g) were randomly distributed among seven dietary treatment groups, with three replicates per treatment, and were fed experimental soybean meal-based diets for 90 days. The dietary treatments comprised a control diet (D1); diets supplemented individually with Moringa oleifera (D2), Phyllanthus emblica (D3), Allium sativum (D4), Blepharis repens (D5), or Ziziphus mauritiana (D6); and a polyherbal formulation containing all five medicinal plants (D7). Growth performance, feed utilisation efficiency, haematological parameters, serum biochemical indices, and hepatic antioxidant indices were evaluated. Data were analysed using one-way analysis of variance (ANOVA), followed by Tukey's honestly significant difference (HSD) multiple-comparison test, with statistical significance set at P < 0.05. Results: Dietary supplementation with medicinal plants significantly improved growth performance, physiological health, and antioxidant capacity compared with the control (P < 0.05). Fish fed the polyherbal diet had the highest final body weight (78.62 ± 1.84 g), weight gain (58.31 ± 1.71 g), specific growth rate (1.62 ± 0.03% day⁻¹), protein efficiency ratio (2.18 ± 0.05), and survival rate (99.0 ± 0.6%), and the lowest feed conversion ratio (1.39 ± 0.04). Haematological indices, including erythrocyte count, leucocyte count, haemoglobin concentration, and haematocrit, increased significantly in all phytogenic treatments. Serum total protein, albumin, and globulin concentrations increased significantly, whereas glucose, cholesterol, triglycerides, and hepatic enzyme activities (AST, ALT, and ALP) decreased significantly, indicating improved metabolic and hepatic status. Antioxidant indices, including superoxide dismutase, catalase, and glutathione peroxidase activities and reduced glutathione concentration, increased significantly, whereas malondialdehyde concentration decreased markedly. Among the individual medicinal plants, Phyllanthus emblica and Moringa oleifera produced the greatest beneficial effects; however, the polyherbal formulation consistently yielded the best overall response across the evaluated parameters. Conclusion: Supplementation of soybean meal-based diets with indigenous medicinal plants, particularly as a polyherbal formulation, enhanced growth, haematological characteristics, metabolic health, and antioxidant defence in Labeo rohita. These findings suggest that locally available phytogenic feed additives may provide economical, environmentally responsible, and sustainable alternatives to synthetic growth promoters for improving fish health and productivity in freshwater aquaculture.