en Biology & physiology Biology & physiology پژوهشي Orginal research papers <span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: FA">Growth performance, carcass composition, and immunophysiological indices in juvenile great sturgeon (<i>Huso huso</i>) fed on commercial prebiotic Immunoster (IS) were investigated. After a four-week acclimatization period, 270 great sturgeon juveniles weighing 95.68 ± 10.05 g were randomly distributed into 9 fiberglass tanks in three replicates and kept at a density of 30 fish per tank for a period of 8 weeks at water temperature 20.55 ± 5.11</span>^{<span style="FONT-FAMILY: "Courier New" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: BN">º</span>}<span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: FA">C and dissolved oxygen 6.73 ± 0.35 mg L^-1. IS was added at two levels of 1% and 3% to the basal diet in place of cellulose. At the end of the trial, blood sampling and carcass analysis were conducted. Weight, length, body weight increase (BWI), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER) and condition factor (CF) were significantly affected by IS 3% compared with IS 1% and the control (P<0.05). There was significant difference (P<0.05) in crude protein of carcass between the experimental groups. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) showed significantly higher levels in experimental treatments compared with the control (P<0.05). </span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: BN">Immunoglobulin M</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: FA"> (IgM) level and lysozyme activity in IS 1% group were higher than the control group.</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: BN"> It can be concluded that IS can enhance growth performance and improve some</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: FA"> immunophysiological indices</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: BN"> of</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: FA"> great sturgeon</span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-ansi-language: EN-US mso-fareast-language: EN-US mso-bidi-language: BN">.</span> Huso huso, Prebiotic, Immunoster, Growth Performance, Immunophysiological indices 324 335 http://jifro.ir/browse.php?a_code=A-10-1-89&slc_lang=en&sid=1 R. Ta'ati r.taati@gmail.com 10031947532846001304 10031947532846001304 Yes M. Soltani 10031947532846001305 10031947532846001305 No M. Bahmani 10031947532846001306 10031947532846001306 No A. Zamini 10031947532846001307 10031947532846001307 No