Growth and Immune Responses of Labeo rohita supplemented with combination of fucoidan rich seaweed extract and probiotic

A 60 d feeding trial was conducted to study the combined effect of fucoidan rich seaweed extract (FRSE) from Sargassum wightii and probiotic (Bacillus subtitlis) on growth and immune parameters of Labeo rohita fingerlings. Two hundred and ten fingerlings of uniform size group were distributed into seven experimental groups in triplicates. Each groups were fed to satiation with iso-nitrogenous (35% CP) and iso-caloric (396.3 kcal/100g) purified diets containing 0% FRSE and no probiotic (control), 2% FRSE (T1), 10⁸ CFU g⁻¹ probiotic (T2), 1% FRSE + 10⁵ CFU g⁻¹ probiotic (T3), 2% FRSE + 10⁵ CFU g⁻¹ probiotic (T4), 1% FRSE + 10⁸ CFU g⁻¹ probiotic (T5) and 2% FRSE + 10⁸ CFU g⁻¹ probiotic (T6). Higher weight gain percentage, specific growth rate, protein efficiency ratio and lower feed conversion ratio were recorded in T3, T5 and T6 groups. After feeding trial, the experimental fish were challenged with Aeromonas hydrophila and the best relative survival rate was observed in T6 group followed by T4 whereas, albumin/globulin (A/G) ratio and haemoglobin content exhibited decreasing trend. SOD and catalase activity in liver and muscle were found significantly lower in the groups fed with fucoidan. Hence, both innate immunity and growth parameters can be enhanced using the combination of FRSE and probiotic in the diet of L. rohita.