Effect of dietary seaweed Caulerpa racemosa on growth, biochemical, non-specific immunity, and disease resistance to Pseudomonas aeruginosa in Cirrhinus mrigala

Abstract

The green seaweed Caulerpa racemosa possesses highly potential elements in animal forages and human use since ancient times. The current study was designed to investigate the antioxidants, phytochemical properties of C. racemosa, as well as their effects on growth parameters, biochemical components, non-specific immunological parameters, and disease resistance to P. aeruginosa in Cirrhinus mrigala. The experimental group, divided into five groups as T1–T5. T2–T5, was given C. racemosa extract at concentrations of 0.5%, 2.5%, 4.5%, & 6.5% supplemented with basal diets. T1's group food is devoid of extract and acts as a control, and the trial lasted forty-five days. C. racemosa exhibited dose-dependent antioxidant activity. The highest levels of DPPH (61.21%), ABTS (70.55%), and H2O2 (66.55%) scavenging activities were obtained at 100 µg/ml 100 μg/ml. GC–MS analysis revealed phytoconstituents in the crude extract, such as palmitolinoleic acid, butanoic acid, arachidonate, linoleic acid, vaccenic acid, octadecenoic acid, trans-phytol, and eicosanoids. Among these different concentrations, 4.5% C. racemosa supplemented diet produced a significantly higher growth metrics of C. mrigala’s (WG, SGR, FCR), biochemical constituents, when compared to other concentrations. In a post-challenge trial, 4.5% C. racemosa extract meals increased C. mrigala SOD, CAT, non-specific immune response (lysozyme, NBT, phagocytic activity), and haematological (RBC, WBC, HCT & Hb) parameters when compared to other experiments. The findings revealed that 4.5% of C. racemosa may be supplied in the diet of C. mrigala to regulate better survival growth performance and haematological parameters.