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This research evaluated the influences of two autochthonous probiotics Lactococcus lactis and Weissella confusa, on growth performance, feed conversion efficiency, haematological parameters, immune status and intestinal morphology of Huso huso fingerlings. Fingerlings (N: 480; initial weight, 2.92 ± 0.01 g) were randomly dispersed in four treatments (three replicates) and fed with the diet (crude protein 47%) that fortified by autochthonous probiotics Lactococcus lactis and Weissella ciberia (PB0: control; PB1.5: 1.5 × 107; PB3: 3 × 107; PB4.5: 4.5 × 107) for 56 days. The results revealed that growth in fish fed probiotics diets were increased compared with the control group. Haematological and blood biochemistry indices did not show any differences between groups (p > 0.05). The highest value of complement 3 was observed in the PBP4.5 group (p < 0.05), while other immunological indices were not significant between treatments (p > 0.05). Foregut villi height of fish fed with PB4.5 diet revealed notable differences compared with those of other groups (p < 0.05). The villi height of PB3 and PB4.5 groups were significantly higher than that of the other treatments (p < 0.05). Taken together, the results of this study showed that the optimum range of autochthonous probiotics were 2.5–2.61 × 107 CFU/g in H. huso fingerlings based on broken‐line regression analysis. [ABSTRACT FROM AUTHOR]

To characterize the effects of a poultry by‐product (PBM) on the gonadosomatic, physiometabolic indices, digestibility and digestive enzymes of juvenile Huso huso (28.42 ± 0.17 g), we procured six experimental diets with 0 (control), 20%, 40%, 60%, 80% and 100% PBM to replace fishmeal. After an 8‐week feeding trial, results confirmed that the weight gain, the specific growth rate of fish fed the 80% and 100% diets were markedly inferior to other groups (p < 0.05). Also, the highest feed conversion ratio and the lowest protein efficiency ratio were observed in dietary of full replacement of fishmeal by PBM (p < 0.05). Triglyceride and cholesterol significantly increased in the PBM100 than the control and PBM20 (p < 0.05). Gastrointestinal enzyme activities were notably decreased in fish fed the diets of more than 60% substitution of fishmeal by PBM (p < 0.05). No statistical difference was observed in the digestibility of protein, dry matter, lipid and gross energy in fish fed up to 300 g/kg (PBM60) of PBM, while beyond this level, all of ADCs value reduced (p < 0.05). Taken together, the optimum range replacement by PBM was 235.9–251.8 g/kg in juvenile Huso huso diet based on the broken‐line regression analysis. [ABSTRACT FROM AUTHOR]

In order to determine the chelating effect of activated charcoal, a total of 150 beluga (270 g) were fed for 60 days with a diet containing 0 (control), 5, 10, 15 and 20 g activated charcoal per kg. Afterwards, the fish were subjected to challenging with 1 mg/L of each of heavy metals including lead, cadmium and copper during seven days. As results, the highest percentage of body weight gain, specific growth rate, condition factor, protein efficiency ratio and the lowest feed conversion ratio before and after challenging with heavy metals were obtained in 15 g treatment with significant differences comparing to other treatment (p < .05). In all treatments, considerable differences were observed between two experimental stages of all parameters except condition factor and feed conversion ratio (p < .05). No mortalities were observed during the experiment. Before challenging with heavy metals, 15 g treatment showed the lowest activities of AST and ALT enzymes, and uric acid, protein, albumin and cholesterol amounts. The minimum amounts of creatinine and glucose were recorded in the control and 20 g treatments respectively. The highest levels of these parameters, except for creatinine and uric acid, were measured in the control group. After challenging with heavy metals, the lowest levels of AST and ALT enzyme activities, uric acid, creatinine, and glucose, and the highest amounts of protein, albumin and cholesterol belonged to 15 g, whereas the results in the control group were almost opposite. In all treatments, significant differences were observed between two experimental stages of all parameters except AST, uric acid, glucose and cholesterol (p < .05). In the pre‐challenge stage, the maximum amount of carcass protein was observed in 15 g while the differences in lipid content were not significant (p > .05). Moreover, the highest contents of moisture and ash were measured in the control group and 20 g respectively. After the challenge, the highest values of protein and lipid were quantified in 15 g, while the maximum values of ash and moisture were observed in 20 g and control group respectively. Also, significant differences were observed just in ash and moisture amounts in both stages (p < .05). Accumulations of cadmium, copper and lead were maximal in the control group in both stages, and their amount were decreased in sample with 15 g of activated charcoal until they reached to their lowest value in sample with 20 g of activated charcoal. The only different parameter between two treatments was copper amount. Also, significant differences were observed in all treatments in both stages (p < .05). Although activated charcoal at 20 g/kg diet yielded the best results in metal chelation, it is recommended to add 15 g/kg of activated charcoal to the diet of beluga because of other parameters. [ABSTRACT FROM AUTHOR]

The effectiveness of common carp pituitary extract ( CPE), luteinizing hormone releasing hormone analogue ( LHRH-A2) injections and LHRH-A2 implants for spawning induction in female sturgeon, Huso huso was examined. In the first trial, fish were injected with 7% physiological saline (control), 50 mg kg−1 CPE or LHRH-A2 at 3.5, 7, 8 or 10 μg kg−1. In the second trial, fish were treated with LHRH-A2 cholesterol pellet implants containing 0, 3.5, 7, 8 and 10 μg kg−1 LHRH-A2. Ovulated eggs were removed using a minimally invasive surgical technique and were artificially fertilized. Injection of CPE and LHRH-A2 at doses of 3.5, 7, 8 and 10 μg kg−1 resulted in the number of ovulated fish more than LHRH-A2 implants (similar doses) or controls, although there was no significant difference at doses of 8 and 10 μg kg−1 ( P ≥ 0.05). The latency period of fish receiving CPE and LHRH-A2 injections was approximately 20 h, which was significantly lower than in fish receiving LHRH-A2 implants ( P ≤ 0.05). Furthermore, there were no significant differences in rates of fertilization or hatching among the progeny produced in any of the treatment groups ( P ≥ 0.05). In conclusion, the data from this study could be useful for artificial propagation of not-fully-matured females of H. huso at sturgeon hatcheries. [ABSTRACT FROM AUTHOR]

A 10-week feeding trial was carried out to evaluate the optimum dietary protein level for the maximum growth of juvenile beluga, Huso huso. Fish averaging 1.34 ± 0.07 g (mean ± SD) was randomly distributed into 18 circular fibreglass tanks of 500 L capacity (20 fish per tank). Six iso-caloric diets were formulated to contain 30 ( CP30), 35 ( CP35), 40 ( CP40), 45 ( CP45), 50 ( CP50) and 55% ( CP55) crude protein ( CP). Fish were fed each of the six experimental diets in triplicate groups. At the end of feeding trial, weight gain ( WG) and specific growth rate ( SGR) in fish fed CP40 and CP45 diets were significantly higher than those of fish fed CP30, CP35, CP50 and CP55 diets ( P < 0.05). Lipid retention increased significantly from 24.7% to 31.6%, but protein retention decreased from 54.6% to 35.6% with increasing protein levels from 30% to 50%. Muscle total essential and non-essential amino acid ( EAA & NEAA) concentrations increased with the dietary protein level up to CP45 diets. Muscle total EAA concentrations (%) of fish fed CP45 were significantly higher than those of fish fed CP30, CP35, CP50 and CP55, but there was no significantly different between those of fish fed CP40 and CP45. Muscle total NEAA concentration (%) of fish fed CP45 were significantly higher than those of fish fed CP30 and CP35 diets. Broken-line analysis of WG suggested that the optimum dietary protein level could be 38.9% for maximum growth performance in juvenile beluga (1.3-77 g). [ABSTRACT FROM AUTHOR]

In this work, we investigated the effects of various feeding treatments on the survival and growth of Huso huso and Acipenser persicus larvae during a 20-day culture period. Three replicate groups (250 fish/replicate) of first-feeding larvae were fed according to four main feeding regimes: (1) live food (live nauplii of brine shrimp Artemia urmiana); (2) indirect transition (5-7 days live food followed by gradual transition to formulated diet); (3) direct transition (using different combinations of live and formulated diet from the start feeding onwards); and (4) formulated feed ( FD) from the start of feeding. In H. huso larvae, combining live food and manufactured diets (co-feeding) from the first feeding stage onwards (direct transition) resulted in significantly higher weight gain than the other regimes. Survival was significantly higher in H. huso larvae fed solely live food or the direct transition regimes compared with indirect transition and FD. In A. persicus larvae, growth and survival were higher in the indirect transition feeding regime than in the other regimes. On the basis of the results of this study, we recommend co-feeding of H. huso immediately from the commencement of exogenous feeding, but co-feeding of A. persicus should start 7 days after prior feeding with live food. [ABSTRACT FROM AUTHOR]

Growth performance, carcass quality, survival and haematological responses were determined when Huso huso juvenile (41.7±1.8 g) fed diets containing Ergosan (an algal product) at 0, 2.0, 4.0 and 6.0 g kg−1 for 60 days. Each diet was fed to triplicate groups of fish at 10-day intervals (1–10, 20–30 and 40–50 with non-supplemented diets and 10–20, 30–40 and 50–60 with supplemented diets). Results showed that fish fed diets containing Ergosan had significantly higher growth than the control group ( P<0.05). Survival was not different among all dietary treatments ( P>0.05). Food conversion ratio in the fish fed a diet containing 4.0 and 6.0 g kg−1 Ergosan was significantly better than the other treatments ( P<0.05), whereas protein efficiency ratio was not different between experimental diets. Lymphocyte count in the fish fed diets containing Ergosan was higher than the other treatments. Haematocrit, haemoglobin (Hb) concentration, number of erythrocytes, total leucocytes, monocyte, eosinophil, myelocyte, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration were not different between treatments. Neutrophil count in the control group was higher than the fish fed supplemented diets. Furthermore, whole body lipid, moisture and fibre were not different among dietary treatments ( P>0.05) but body protein in the fish fed a diet containing Ergosan at the level of 2.0 and 4.0 g kg−1 was higher than the other treatments. Whole body ash content was higher in the control group. It was concluded that dietary administration of Ergosan can influence some growth and haematological parameters in great sturgeon, H. huso juveniles. [ABSTRACT FROM AUTHOR]