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A 12-week feeding trial was carried out in 500 L fiberglass tanks  to evaluate the effect of dietary choline at 0, 2, 4, and 8 g kg ^-1 levels on growth rate, body composition and total liver lipid of juvenile Acipenser baerii (37.67±0.67 g). A semi purified basal diet was formulated using vitamin free casein and wheat gluten as a protein source, a mixture of animal and plant oils as a lipid source and dextrin as a carbohydrate source. Four isonitrogenous (40% protein) and isoenergetic (18 MJ kg^-1) diets were prepared and fed to the fish three times daily to apparent satiation. Weight gain, feed conversion ratio (FCR), specific growth rate (SGR) and protein efficiency ratio (PER) were significantly affected by dietary choline (p<0.05). The best growth performance was observed in fish fed diets containing 2 and 8 g kg ^-1 choline (p<0.05). Fish fed with 2 and 4 g kg ^-1 choline showed higher lipid content compared with the control diet (p<0.05), but not significantly different in body protein (p>0.05). Total lipid of liver and plasma, plasma cholesterol, triglyceride and phospholipids levels showed an increasing trend with increasing levels of dietary choline, but not significantly different among treatments (p>0.05). Based on the results, we recommend adding a 1.5 gkg^-1 choline to commercial diet of juvenile Acipenser baerii.

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The effect of Pediococcus pentosaceus as a probiotic on the growth and immunological factors of the Siberian sturgeon, Acipencer baerii, was assessed. For this purpose, 180 fish specimens of 143.3±0.01 g body weight were randomly distributed in 12 fiberglass  tanks (15 fish per tank) and fed with four diets containing 10⁷, 10⁸ and 10⁹  bacterial cells per gram, respectively. The forth diet (control) contained no probiotics. Results showed significant improvement in FCR, PER, SGR and BWI in groups fed on diets containing probiotics compared to the control group. However, CF decreased in the probiotic- treated groups, though not significant. The result of immunological factors indicated increased lyzozyme activity, ACH50 and total igM. The best result from the assessment of immune factors was observed in the fish fed with 10⁹ bacteial cell per gram of diet.

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This study was carried out to evaluate the effect of different sources and levels of carbohydrate (glucose and corn starch) on growth performance and carcass composition of juvenile Siberian sturgeon (Acipenser baerii). Two weeks after acclimatization period to rearing conditions and basal diet, the number of 120 Siberian sturgeon juveniles weighing 25.64 ± 2.80g were randomly distributed into 12 fiberglass tanks in four treatments (glucose 15%, glucose 30%, corn starch 15% and corn starch 30%) in three replicates and kept at a density of 10 fish per tank (one fish per 35 liter) for a period of 8 weeks. Results showed that final weight, final total length, percentage of body weight increase, specific growth rate, mean daily growth, protein efficiency ratio and condition factor in fish fed corn starch 15% were high in comparison with other treatments (P>0.05). Fish fed corn starch 15% had the lowest (P>0.05) food conversation ratio. Significant difference was seen between fish fed corn starch 30% with fish fed glucose 15% in HSI (P0.05). The highest content of carcass protein was seen in corn starch 15% that showed significant difference with treatments glucose 15% and 30% (P

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Protein hydrolysate (PH) from viscera of cultured Siberian sturgeon (Acipenser baerii) was produced. To optimize the production conditions, Response Surface Method (RSM) was employed to examine the effects of three different operating conditions, including time, pH, and enzymatic concentration (Alcalase) on the degree of hydrolysis.The mathematical model showed acceptable fitness of the experimental data as R2 equaled 0.97, which indicated  that   major part of  the  variability  within  the  range  of  values could  be explained  by  the  model. The results showed that the highest degree of hydrolysis (58.21%) was related to the treatment which happened at the enzymatic concentration of 2%, 60 minutes time, and pH=8. Treatment under hydrolysis condition (i.e., E/S = 2%, Time = 45 min, and pH = 8.5) had the highest protein content (42.37g/l), which was used as an alternative to commercial peptone medium (Triptic soy broth) to assess the growth of Salmonella typhi bacteria from 0 to 48 hours. Although there was an upward trend in growth rate of S. typhi both in control and No. 15 (Alcalase) treatments, the log growth of control treatment was found to be better than that of Alcalase treatment. However, there existed no significant difference between the two treatments.