The effect of dietary dextrin levels on growth performance, body composition and hepatosomatic index in juvenile Siberian sturgeon, Acipenser baerii

The present study was carried out to determine the ability of Acipenser baerii in utilizing carbohydrate (dextrin) as a non protein energy source substituted with animal oil. A total of 65 juveniles A. baerii with an initial mean weight of 689 ± 62 g were distributed in 15 fiber glass tanks. Five diets were formulated including 0, 5, 10, 15 and 20% of dextrin and fed for 8 weeks. Fish were weighed monthly and growth was evaluated in each treatment. At the end of experiment, body composition and hepatosomatic index were analyzed. There was no significant differences in body weight increase (BWI) and final weight (FW) among different groups (p>0.05). Increase of dextrin levels in diets led to an increase in feed conversation ratio (FCR) in fish fed diets containing 15 and 20% dextrin as compared to that in the control group and in fish fed the diet containing 10% dextrin although the differences were not significant (p>0.05). The specific growth rate (SGR) in all treatments were the same (p>0.05). The highest body protein and lipid were observed in fish fed diets containing 10 and 20% dextrin, respectively (p0.05). In conclusion, juvenile A. baerii can be fed diets with high levels of dietary dextrin as a non protein energy source with no deleterious effects and a partial replacement of cheap carbohydrate with lipid is suggested to obtain the necessary energy in commercial diets

Primary culture of ovarian follicular cells of Sterlet, Acipenser ruthenus to develop an in vitro system

The aim of the present study was to develop an in vitro system for functional investigation of ovarian follicular cells in Sterlet, Acipenser ruthenus. Oocytes for the primary culture were obtained from the ovaries of a 6 years old Sterlet 729 g in weight and 47 cm in total length. The oocytes were in advanced vitellogenesis stage (PI >10). A part of the ovary (containing about 300 follicles) was removed, ovarian follicles isolated by manually removing those from the interstitial tissue and washed with sterile phosphate buffered saline (PBS) containing antibiotics and Amphotericin B. Follicular cells were separated by treating oocytes with 0.25% trypsin-EDTA in Ca2+ and Mg2+ free PBS and cultured in medium L-15 supplemented with 20% FBS, streptomycin sulphate (Gibco, 100 mg.ml-1), penicillin G potassium (Gibco, 100 IU.ml-1) and Amphotericin B (Gibco, 2.5 mg.ml-1) at 22 °C. The concentrations of Testosterone (T), Estradiol-17β (E2), Progesterone (P4) and 17α-hydroxyprogestron (17αOHP) in the medium were measured at days 3, 5 & 7 by the Enzyme-Linked Immunosorbent Assay. According to the results, the ovarian follicular cells of Sterlet proliferated in L-15 medium were steroidogenically active as expressed by the secretion of T, E2, P4 & 17αOHP. Testosterone was the dominant hormone secreted by cultivated follicular cells, which was correlated closely with the end of vitellogenesis in the isolated oocytes. Decrease in production of these hormones was greater at days 3 & 4 in comparison with those at days 5 & 6. By successfully culturing ovarian follicular cells of Sterlet in L-15 culture medium, an in vitro system was developed which enables functional studies to be carried out similar to the in vivo situation in the ovarian follicles

Utilization of corn gluten meal as a protein source in great sturgeon (Huso huso) diets in growth up stage

The utilization of corn gluten meal (CGM) was evaluated as a replacement for fish meal (FM) in practical diets for beluga Huso huso in growth up stage. Four experimental diets (isonitrogenus and isocaloric , 40 % protein and 18 kj/ g diet) were formulated. Fish meal was replaced by CGM at 0%, 20%, 40% and 60% being named as CGM0, CGM20, CGM40 and CGM60, respectively. Fingerlings great sturgeon with an initial body weight of ± 78.876.94gr (mean ±SD) were reared in 12 fiberglass tanks and fed with diets for10 weeks at 20.00± 2 oC. At the end of experiment, growth performance (final weight, body increase weight, specific growth rate) of fish fed CGM20 and CGM40 were significantly higher than fish fed control diet, While feed conversion ratio were lower than fish fed CGM40 and CGM60 compared with control diet. There were not significant difference in condition factor, protein efficiency ratio and body protein in different experimental groups , but body lipid increased as dietary gluten meal increased (P<0.05). Different levels of corn gluten meal did no significantly affect Aspartat amino transferas (AST), Alanin amino transferas (ALT) and Triglyceride, but amount of cholesterol in fish fed diets CGM40 and CGM 60 were significantly lower than control diet (P<0.05). The present study revealed that CGM is a suitable source as replacement with fish meal and might be included in great sturgeon commercial diet up to 60 % with no adverse effect on nutrition efficiency, liver enzymes and biochemical parameters

Utilization of poultry by product meal as an alternative protein source for Huso huso within growth period

With regard to increasing the fish meal price, utilization of hygienic and analyzed poultry by product meal as an alternative protein source in diets for Huso huso within growth period were investigated. Six test diets isonitrogenous and isocaleric (contain 42% protein and 20 Mj kg-1 energy) were prepared. Fish meal was substituted by poultry by product at 20% (PBM20), 40% (PBM40), 60% (PBM60), 80% (PBM80) and 100% (PBM100) in base diet, respectively. A total of 180 Huso huso with average (±SD) weight of 107.89±5.9gr were stocked in 18 fiberglass tanks (Voloum:2000 lit,Temperature:20±2C 0) and fed satiation to 18 weeks. No significant differences were detected between final weight (FW),weight gain (WG) and specific growth rate of fish fed (PBM0), (PBM20), (PBM40), (PBM60) and (PBM80) respectively. The Highest protein belonged to fish fed PBM20 (%16.97±0.36) with significant difference with PBM40 (% 15.41 ± 0.67), respectively. Body lipid fish fed PBM80 and PBM100 (%6.63±0.016) (%7.49±0.17) were significantly lower than other treatments. The Synchronic hepatosomatic index increased with increasing poultry by product in diets and highest rate were found in fish fed PBM 100 , but except PBM20, visceral index in fish fed other treatments was same. The result showed that up to 80% fish meal could be replaced by poultry by product with no adverse effect on growth and feed conversion ratio for Huso huso within growth period

Effects of different oxygen level on growth and muscle composition in two weight groups of great surgeon Huso huso

The aim of the present study was to evaluate water oxygen concentration on growth and muscle composition of great sturgeon, Huso huso, in two weight groups (initial weight 280.9±49.2 and 1217.9±138.1). Oxygen treatments including hypoxia (2-3 mg/l), normoxia (5-6 mg/l) and hyperoxia (9-10 mg/l) were prepared by adjusting inflowing water and utilizing equipments for providing hyperoxygenation (pure oxygen injected). Fish were acclimated to experimental tank for one week, then each group were randomly distributed in 9 tanks (3 fish per tank in higher weight group and 6 fish per tank for lower one) for 8 weeks and then growth parameters were determined. There were significant differences between treatments for Wt, WG, BWI, FI and SGR in both groups and CF in higher weight group (P0.05) but wet and fat showed significant differences between treatments in higher weight group(P<0.05). Results indicate thathigh oxygen level has a direct effecton growth performance of great sturgeon, so it is recommended for great sturgeon

Big bester production probability study

Aquaculture of sturgeon species and their hybrids is being considered as an important substitution for sturgeon catch due to highly decrease of natural populations, artificial propagation and fingerling release in the sea. In this study, big bester, a new hybrid sturgeon (female beluga × male bester) was produced for the first time in IRAN. Sperm of 7350 ± 1682 kg male bester was used to fertilize the eggs of one 54 kg female Huso huso. The fries of big bester and control treatment of beluga were fed by artificial concentrated food (48-50% protein and 15-17% fat) after egg yolk absorbance, a period of feeding on Artemia and Daphnia. Results showed that rearing and feeding of bester broods was efficient to reach the fish to maturation stage and there is an opportunity to collect qualified ova and sperm from F1 generation. Meanwhile sex determination and maturity assessment of gonads were successfully done via laparoscopy method. The comparison of produced big bester fingerlings with control beluga fingerling showed that the weight of big bester fingerlings has not significant difference with beluga's (p0.05), but there are faster growth rate in big bester fingerlings from 3 months of age up to 5 months (p>0.05) in comparison with belugas fingerlings. Meanwhile no statistically significant difference was found between length of big bester and beluga fingerlings among any age. The results of current study showed the potential of rearing male bester to produce matured broods and collection of their sperm for big bester production

Study of possibilities of replacement of fish meal by poultry by product in formulated diet of Huso huso

To regard to dramatic decreasing of pelagic fish and depending on fish meal for sturgeon Feeding a project with title on "Study of possibility of replacement of fish meal by poultry by product in formulated diet of Huso huso" in two faz (fingerling) and (Growth out) were carried out. In first faz, proximate composition of fish meal, poultry by product and diet ingredient were determined , thereafter Six test diets (contain 45% protein and 19 Mj kg^-1 energy) were prepared based on anchovy fish meal and poultry by-product substituted at levels of 20% (PBM_20), 40% (PBM_40), 60% (PBM_60), 80% (PBM_80) and 100% (PBM_100), respectively. Huso huso Fingerlings (28.42±0.17gr ± SD) were stocked in 18 fiberglass tanks and fed to satiation to eight week. Result indicated the highest final weight (FW), Weight gain (WG), Specific growth rate (SGR) and Protein efficiency ratio (PER) were belonged to control diet (350.52 ±21.86_gr),(1133.00 ±74.84%),(3.74±0.092 %per day) and (1.58 ±0.017) respectively. But No significant difference was detected between FM, PBM_20, PBM_40 and PBM_60 (P>0.05), Also, there were not significant difference in treatments for Feed efficiency Ratio between (PBM_0), (PBM_20), (PBM_40), (PBM_60) (PBM_80) respectively (P0.05).The best feed efficiency ratio belonged to fish fed PBM_40 that no significant differences with (PBM_20), (PBM_60) and (PBM_80) (P>0.05).a significant decrease of body lipid observed by increasing of supplementation of poultry by product in diets that lowest body lipid (6.6±0.16) were stabilized in (PBM_80) (P0.05). also hepatosomatc index were significantly increase by increasing of poultry by product in diets respectively that highest were observed in fish fed PBM100 (4.2±0.63) (P<0.05).Result of this investigation indicated that poultry by product had high potential for replacing of fish meal in fingerling and growth out Huso huso diet. Therefore suggested a investigation design for research about the effect of poultry by product on growth rate, body composition and immune system of Huso huso at long period for introduce a new replacer product Instead Of fish meal in sturgeon aquaculture industry

Effects of olive pomace on growth performance, digestibility, body composition and fatty acid profile in yearling Siberian sturgeon, Acipenser baerii (Brandt 1896)

Replacement of olive pomace (OP) with wheat flour in diet was studied in diet of yearling Siberian sturgeon (Acipenser baerii). Fish (165 ± 6.8 g) were randomly allocated to 15 fibreglass tanks (15 fish/tank, in triplicate). Fish were assigned to one of five dietary treatments at 19.1 ± 1.5°C for 8 weeks: control diet (crude protein and crude lipid at 514.6 and 188 g/kg, respectively) and four experimental diets with 20, 50, 75 and 100 g/kg OP to replace wheat flour in the experimental diets. No significant difference was observed in the final weight, feed conversion ratio, specific growth rate, hepatosomatic index, viscera‐somatic index and survival rate among the treatments (p > 0.05). No change was seen in digestibility of protein and lipid in diets containing 20 g/kg and 50 g/kg OP compared to control group, while these values decreased with increasing in OP above 50 g/kg. Digestibility of dry matter and gross energy among the treatments demonstrated no significant difference (p > 0.05). Polyunsaturated fatty acids, especially C22:6n3 (DHA), in the muscle of the fish fed 75 g/kg and 100 g/kg OP in diets were significantly higher than control group (p < 0.05). These data show that OP could be recommended as a substitute for wheat flour in diet of S. sturgeon but its utilization for other species warranted future works

Immuno-physiological and antioxidant responses of Siberian sturgeon (Acipenser baerii) fed with different levels of olive pomace

Nowadays, use of the natural plant derivatives as an immunostimulant in aquaculture is becoming more useful than antibiotics which are destructive to target animals, consumers, and the environment. The present study aimed to evaluate the efficacy of dietary substitution of wheat flour at 2, 5, 7.5, and 10% of olive pomace (OP2, OP5, OP7.5, and OP10) in some immune-physiological and antioxidant variables of yearling Siberian sturgeon (Acipenser baerii) weighing 165 ± 6.8 g at 19.1 ± 1.52 °C for 56 days. Fifteen fish per tank were randomly accommodated in triplicates per treatment and the control group was also included. No significant difference was seen in hematological indices including red blood cells (RBS) and immunocompetent cell population sizes among the treated groups (P > 0.05). Also, malondialdehyde (MDA) activity and superoxide dismutase (SOD) in serum remained unaffected in different treatments (P > 0.05). Total protein (TP), high-density lipoprotein (HDL), catalase (CT), and lysozyme were affected by dietary OP levels (P < 0.05), and the highest value was observed at the OP5 diet, but no influence was seen in serum IgM by OP. These data show that application of olive pomace as a partial substitute of wheat flour in the diet of Siberian sturgeon is feasible with stimulatory and antioxidant functions