Effect of dietary Solanum nigrum on growth, immunity, and disease resistance against Aeromonas hydrophila infection in Labeo rohita (Hamilton, 1822) fingerlings

Abstract

Solanum nigrum leaf meal (SNLM) could be a promising phytobiotic with growth and immunomodulatory effects in aquaculture species. Phytochemical profiling revealed a diverse composition of bioactive constituents, which includes flavonoids, phenolic acids, terpenoids, amino acids, minerals, and vitamins. Further, a sixty-day feeding experiment was undertaken to study the influence of SNLM-incorporated diets on growth promotion, haematobiochemical indices, and immunological responses in rohu infected with Aeromonas hydrophila . Control and SLNM incorporated diets containing graded concentrations of SNLM, viz., 0%, 0.25%, 0.5%, 1.0%, and 2.0% were fed to fish. The results revealed a pronounced elevation in growth parameters in the 2.0% SNLM-fed group. The haematological and immunological parameters, including RBC, PCV, haemoglobin, lysozyme, respiratory burst, and myeloperoxidase activity were highest in rohu fed with 2.0% SNLM diet. Furthermore, dietary SNLM notably enhanced serum protein, albumin, and globulin levels, while curbing triglycerides, glucose, cholesterol, ALT, and AST after pathogen challenge. The SNLM groups demonstrated substantially higher cumulative survival compared to the post-challenge control group against A. hydrophila . Hence, this study established that supplementation with SNLM at 2.0% level significantly improved growth, haematological, and immunological responses, and lowered mortality of L. rohita against A. hydrophila infection, indicating its potential as a phytobiotic aquafeed additive.