فهرست مطالب رضا قربانی واقعی

This study aimed to evaluate the effects of feeding with different types of live feeds on growth performance, survival rate, body composition, and fatty acids profile of great sturgeon (Huso huso) larvae during short-time weaning to dry feed. A total of 1200 great sturgeon larvae with a mean initial weight of 0.43±0.01g were distributed randomly into twelve 80-L circular fiberglass tanks (100 larvae per tank) with three replicates. Afterward, the fish were fed with frozen chironomid larvae (T1), frozen Artemia biomass (T2), and a combination of them (T3). The control group © received only a commercial dry feed (0.5 mm: protein 55.59%, lipid 21.12%, ash 11.76%, and moisture 7.96%) throughout the feeding trial. For weaning, the live feed was reduced by 15% every two days, and the dry feed ratio was also gradually increased. According to the results, the final weight (4.99±0.16g), weight gain (4.57±0.17g), body weight increase (1081.53±72.75%), and specific growth rate (11.75±0.29%/day) were significantly higher in T1 than in other groups (p<0.05). The survival rate (56.50±1.32%) significantly decreased in the control group © (p<0.05); however, no mortality was observed in the group fed chironomid larvae (p<0.05). The crude lipid (1.32±0.08%) and moisture (80.98±0.17%) levels of T1 were higher than other groups, and the crude protein content was significantly higher in T3 (11.26±0.39%) and C (11.44±0.44%) than T1 (9.23±0.39%) and T2 (9.67±0.28%) groups (p<0.05). There was a significant decrease in total n-3 LC-PUFA fatty acids (9.53±0.04%) in T3 than in T1 (11.02±071%) (p<0.05). The EPA/DHA ratio in T1 was significantly higher (0.45±0.03%) than other treatments (p<0.05). Consequently, the administration of frozen chironomid larvae is recommended during a 21-day adaptation period of great sturgeon larvae to the dry feed, due to the optimizing effects on growth indices, survival, and fatty acid contents.

Thiamine, or vitamin B1, is an important coenzyme in lipid, carbohydrate, and protein metabolism that plays a vital role in the embryonic stages and larval development. To evaluate the effects of thiamine on incubation indices of beluga Huso huso, eggs obtained from farmed males and females after fertilization were immersion in water-soluble thiamine with four treatments and two replicates including control (0 mg thiamine per liter of water), T500 (500 mg thiamine per liter of water), T1000 (1000 mg thiamine per liter of water) and T1500 (1500 mg thiamine per liter of water) during water hardening for 30 minutes. Then, eggs were washed five times with fresh water and kept in special incubators until hatching. Incubation indices and larval growth were investigated 24 hours after fertilization to 44 days after starting feeding. Results showed the highest and lowest egg survival at 24 hours after fertilization until hatching were observed in T1500 and control, respectively (P<0.05). At the start of the feeding the results showed no significant difference in larval weight and length (P>0.05). However, thiamine increased the weight, length, and weight gain in T1000 and T1500 at the end of the experiment (P<0.05). Egg immersion in soluble Thiamine led to an increase in the specific growth rate and body weight in T1000 and T1500 at day 36 after the start of feeding (P<0.05). The food conversion ratio, protein efficiency ratio, and lipid efficiency ratio significantly decreased in control and T500 compared to other treatments (P<0.05). The lowest larval survival was observed in control at the beginning of feeding until day 44 (P<0.05). The results of this study indicate that immersion of eggs in thiamine solution can increase larval growth and survival. Therefore, it is recommended that beluga eggs immersion in thiamine solution at least 1000 mg L-1 thiamine after fertilization

The present study was designed and implemented to evaluate the effects of relative replacement of different levels of dehulled soybean meal (DHSM) instead of fish meal on growth performance of adult Persian sturgeon (Acipenser persicus). In this study, a total of eighty 4-year-old Persian sturgeons (Acipenser persicus), with an average weight of 3850 g were fed with 8 isonitrogenetic and isolipidic diets for 52 weeks. Experimental diets include different percentages of dehulled soybean meal include 0, 10, 15, 20% without amino acid, 15 and 20% replacement with lysine and methionine, and 15 and 20% replacement with lysine and methionine and L-carnitine supplement (DHSM0, DHSM10, DHSM15, DHSM20, DHSM20+AA, DHSM15+AA, DHSM20+AA+L.car. DHSM15+ AA+L.car.). After 52 weeks, no significant difference was observed between weight gain (WG), specific growth rate (SGR), LX and PV in different treatments. The protein efficiency ratio and feed efficiency (FE) in DHSM0 was significantly higher than that of DHSM20+AA and DHSM15+AA. Hepatosotic index of fish in DHSM0, DHSM10, DHSM15, DHSM20 + AA+L.car. DHSM30 + AA+L.car. was significantly higher than that in DHSM30 + AA. Gonadosomatic index exhibited alterations under the influence of the diet.  Effect of diets containing dehulled soybean meal with L-carnitine supplement on the reproductive system of female fish was significant and positive. The somatic growth in female Persian sturgeon was higher than that of males. However, their gonadic growth and stages of sexual maturity were significantly lower than that in males. The highest sexual maturity index of male fish was observed in DHSM15 + AA+L.car diet, so that at the end of the rearing period, 75% of fish were in stage IV of sexual maturity and 25% in stage III-IV. Addition of L-carnitine and essential amino acid supplement such as lysine and methionine to the diet containing soybean meal displayed a positive effect on the growth and reproductive indicators in the functional diet of Persian sturgeon and probably can improve significantly the production of Persian sturgeon fry.

Due to the many effects of dietary nucleotide such as increasing the immune system, reducing stress, disease resistance, better growth and longer survival, the present study was designed and performed to investigate the effect of dietary nucleotide supplementation (ascogen) on hematological parameters and carcass composition of Siberian sturgeon (Acipenser baerii). Ascogen has optimal levels of RNA and nucleotides. In this regard, 450 fish (39.77 ± 10.24 g) were distributed in 15 tanks (300 liters). Fish were fed with 5 nucleotide treatments including control treatment (0 g/kg), treatment 1 (0.2 g/kg), treatment 2 (0.4 g/kg), treatment 3 (0.6 g/kg) and treatment 4 (0.8 g/kg) was selected in 3 replications for 63 days. Fish were fed about 3% of body weight in 4 meals. At the end of the period, it was determined that the fish were fed with treatments 3 (0.6 g/kg) and 4 (0.8 g/kg) in terms of hematological indices and treatment 4 (0.8 g/kg) in terms of carcass composition had better performance than other treatments. Therefore, treatments 3 (0.6 g/kg) and 4 (0.8 g/kg), especially treatment 4 (0.8 g/kg) had the most positive effect and nucleotides were able to induce their positive effects in fish and improved conditions and increased efficiency.

Binders are substances of natural or artificial origin and important in the production of aquatic diets. The binders increase the stability and ability to produce diets and prevent pellets from breaking down in water and during transport. Depending on the raw materials used, the method of making the diet and amount of milling used, the type of aquatic species, and the amount of milling, the type and amount of binder required may vary. Some fish such as trout, salmon, catfish (Channel Catfish) and tilapia eat food quickly and devour good size foods. For these fish, a few minutes of sustained pellet feed in water is sufficient. Also, for sturgeon, the food intake is less than 5 minutes and maximum 15 minutes. Generally, suitable for shrimp is 4-6 hours’ stability of pelleted feed in water. Corn starch, sodium smectite and urea formaldehyde used in the amounts of 2-5, 2 and 0.5-1 percent respectively. Urea formaldehyde is not approved by Europe and Food and Drug Administration (FDA) of America.

In order to examine the cell density and determine the chlorophyll content algas skeletonema sp and Tetraselmis sp in culture F/2 under different salinity 15, 20, 25, 30, 35 parts per thousand were cultured for 15 days. The results of growing in Tetraselmis sp showed that the algas had suitable resistance against vacillations of salinity and they can grow in different salininty. Tetraselimis alga can grow in salinity 30 and 35 parts per thousand and while in Tetraselmis sp alga the best amount of growing were observed in salininty 25 parts per thousand. Time of reaching to the highest density of growing in culture F/2 were significantly different (p 0.05). alga can grow in salinity 30 and 35 parts per thousand and while in Tetraselmis sp alga the best amount of growing were observed in salininty 25 parts per thousand. Time of reaching to the highest density of growing in culture F/2 were significantly different (p 0.05). According to the amount of growing in Tetraselimis with slower growing and go progressive stage with lower speed which show the different behavior of growing amount. In examining the effect of different salininty on amount of chlorophyll alga Tetraselimis there weren’t any differences between cases (p 0.05). the highest amount of chlorophyll were related to cases with salininty 20 parts per thousand salininty with amount 3/33 Micro gremin liter and the lowest amount were related to cases with salinity 35 parts per thousand with amount 1/21 Micro grem in liter. By increasing salinity we can observe the decrease of chlorophyll a in each Mili liter. According to the amount of growing in Skeletonmema is rapid growing and the time of reaching to the highest growing then the death phase. Calculation of effect of salininty on amount of chrollphyll a in Skeletonmema alga showed in density 20 parts per thousand and 25 parts per thousand had more chrollphyll regard to other cases and among the amaunt of least salinity that is 15 Mili gram in liter and amount of most 30 and 35 parts per thousand the statistecs significant differences were not oloserved.