23 research outputs found

    Effects of different carbon sources on water quality, growth performance and survival of western white shrimp (Litopenaeus vannamei Boone, 1931) in zero-water exchange system

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    Effect of different dietary carbon sources on water quality, growth performance and survival of western white shrimp Litopenaeus vannamei post larvae was investigated in zero-water exchange system. Shrimp postlarvae with mean weight of 98.47±8.60 mg and mean length of 22.39± 1.70 mm were fed for 32 days in fiberglass containers with 130 liters volume of water and density of 1 individual per liter in five treatments including one control with water exchange and four biofloc treatments with adding different carbon sources including molasses, starch, wheat flour and mixture of them at equal weight ratios with 15% to 9% of body weight. In the values of water quality parameters including temperature, salinity, dissolved oxygen and pH, no significant differences were observed among the biofloc treatments (P>0.05). Maximum pH (8.27 ± 0.09) and maximum dissolved oxygen (6.37 ± 0.56 mg/lit) was in water exchange treatment. Maximum and minimum level of ammonia was 0.43± 0.34 and 0.09± 0.07 mg/lit in water exchange treatment without floc and biofloc treatment with adding starch of carbon sources, respectively and showed significant difference between treatments (P <0.05). The highest increase in body weight (1640.43± 231.28 mg), growth rate (51.26± 7.23 mg per day), specific growth rate (8.97± 0.42 %/day) and biomass (190.29± 26.83mg) was observed in biofloc treatment with adding molasses and the highest survival rate (90± 0.77%) was obtained in biofloc treatment with adding mixture of carbon sources. The highest feed conversion ratio (1.52±0.23) and the lowest feed efficiency (66.81±7.95) were obtained in water exchange treatment without floc, showing significant difference compared to the other treatments (P <0.05). The results showed that using biofloc technology with zero- water exchange system and adding carbonaceous organic matter could help to recycle waste and improve the water quality. Moreover, the presence of biofloc improved growth performance, feed utilization and production of western white shrimp in zero water exchange rearing system

    Study on nursery growth performance of Pacific white shrimp (Litopenaeus vannamei Boone, 1931) under different feeding levels in zero water exchange system

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    Effect of different feeding levels on water quality, growth performance, survival rate and body composition of Pacific white shrimp Litopenaeus vannamei post larvae were studied in zero water exchange system. Shrimp post larvae with mean weight of 74.46± 6.17 mg were fed for 32 days in 300L fiberglass tanks containing 130L water at density of 1 post larvae L^-1. There were five treatments including control and four biofloc treatments with different feeding levels of 15%, 15%, 12%, 9%, 0% of body weight per day, respectively. The results showed that there were no significant differences in water parameters such as dissolved oxygen and pH between different treatments (p>0.05). There were significant differences in water ammonia level between different treatments (p<0.05). The maximum (0.39 mg/L) and minimum (0.12 mg/L) levels of ammonia were observed in control and biofloc treatment with minimum feeding level (9%BW/day), respectively. The highest body weight gain (1.55g), growth rate (48.50 mg per day), specific growth rate (9.64%/day), biomass gain (182.1g) and body length increase (33.62mm) were observed in biofloc treatment with maximum feeding level. The highest feed conversion ratio and the lowest feed efficiency were obtained in control (p<0.05). The proximate body composition analysis revealed an increase in lipid, protein and ash in biofloc treatments. Results showed that using biofloc technology can decrease water exchange amount and improve feed utilization in nursery culture of Pacific white shrimp. Moreover, presence of biofloc improved the water quality which led to the enhancement in growth performance in nursery stage of shrimp

    Effect of different dietary protein to energy ratios (P/E) on growth performance and body composition of farmed Persian sturgeon (Acipenser persicus)

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    To improve Persian sturgeon nutrition and determine its nutritional requirements, a growth trial was conducted to measure optimum dietary protein to energy ratio in Persian sturgeon sub-yearlings. Four diets: H (P/E=21.33mg/kJ), N (P/E=20.24mg/kJ), L (P/E=19.22 mg/kJ) and M (P/E=18.26mg/kJ) were used in the experiment. Triplicate groups of fish were kept in 500L fiberglass tanks under homogenous culture conditions (dissolved oxygen, light and water flow rate) and fed with the experimental diets. Fish were fed to satiation four times per day during 130 one fourth ¬ days of experiment when the average water temperature and dissolved oxygen were 12.82 plus or minus 1.48 degree C and 9.55 plus or minus 0.18 mg/l respectively. Fish in all treatments grew fast and efficiently utilized the diets. Growth rate, FE, GR, SGR and PER increased with decreasing dietary protein to energy ratios. A higher growth was observed in the fishes fed with lower P/E ratios. Food intake and fatness coefficient increased with increasing dietary energy and decreasing P/E ratios. There were no significant differences in feeding efficiency (FE) and protein efficiency ratio (PER) in fish fed with diet N (high carbohydrate and low lipid content) and diet L (low carbohydrate and high lipid content). We conclude that the Persian sturgeon is able to use lipids and carbohydrates as non-protein sources of energy. The results of the present study demonstrated that the protein content and P/E ratio for optimum growth and efficient protein utilization in Persian sturgeon is 40% and 18.3-19.2 mg protein/kJ energy, respectively

    Effects of water temperature on filtration rate of micro-algae Isochrysis affines galbana by black lip pearl oyster spat (Pinctada margaritifera)

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    This study was conducted to compare the effects of varying water temperatures on filtration rate of micro-algae Isochrysis affines galbana by Pinctada margaritfera spat on microalgae. To determine the optimum temperature and maximum filtration rate, 10 pearl oyster. margaritfera spats with mean total and total hinge length 32.67 ±2.76 and 31.57 ±2.90 respectively were stocked in 70 liter rectangular glass tanks supplied with filtered seawater. The spats were exposed to seven treatments of temperature including 18.5 ±0.21°C, 20.5 ±0.21°C, 23 ±0.1°C, 24.5 ±0.31°C, 26.5 ±0.21°C, 27.5 ±0.15°C and 28.5 ±0.21°C with 3 replicates. The results of filtration on I. affines galbana showed that the maximum filtration of spats on microalgae cells and water volume were 181,324,595 cells and 3626 ml per hour and 635,031,212 cells and 12700 ml per two hours in 27.5 ±0.15°C, respectively. The minimum filtration of microalgae cells and water volume were 5,224,028 and 104ml per hour and 65,874,413 cells and 1317 ml per two hours in 18.50 ±021C, respectively. The results of this study demonstrated that the optimum temperature for maximum feeding of spats on I. affines galbana is 27.5 ±0.15°C

    Effect of different feeding levels on water quality, growth performance and survival of western white shrimp (Litopenaeus vannamei Boone, 1931) post larvae with application of biofloc technology

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    In this study, effect of different feeding levels on water quality, growth performance and survival of western white shrimp Litopenaeus vannamei post larvae were studied in biofloc rearing system. Shrimp postlarvae of PL10 with mean weight of 3±0.7 mg and mean length of 4.4± 0.93 mm were fed for three weeks in fiberglass containers with 200 liters volume of water and density of 10 post larvae per liter in four tretments including one control with water exchange and three biofloc treatments at different feeding levels of 25, 20 and 15% of body weight. According to the results, in the values of water quality parameters including salinity, dissolved oxygen, pH, nitrite and nitrate, no significant differences were observed among the groups (p>0.05). The highest increase in body weight (58.42 mg), growth rate (2.78 mg per day), specific growth rate (15.09 %/day), biomass (84020 mg) and survival rate (71.9%) were obtained in biofloc treatment at 25% feeding level. The highest feed conversion ratio (2.05) and the lowest feed efficiency (48.62%) were obtained in water exchange treatment without floc, showing significant difference compared to the other treatments (P< 0.05). The results from this study reveals that by using biofloc rearing technology can decrease the amount of water exchange and feed utilization compared to body weight in culture of western white shrimp post larvae. Moreover, the presence of biofloc improves growth performance and production of L. vannamei post larvae in biofloc rearing system

    Effect of replacing fish meal with canola meal on growth performance, survival and body composition of Siberian sturgeon (Acipenser baerii Brandt)

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    This study was conducted to evaluate the effect of replacing dietary fish rations with canola rations on the growth rate, survival rate and body composition of the Siberian sturgeon (Acipenser baerii Brandt). Five isonitrogenous (45% crude protein) and isocaloric (18.53 MJg^-1) diets were formulated by replacing 0 (control), 10 (C_10), 20 (C_20), 30 (C_30) and 40% (C_40) of fish rations with canola rations. Juvenile fish with an initial weight of 22.80 ± 0.34 g (mean ± SD) with five treatments and three replications were fed for 10 weeks. At the end of the experiment, the growth rate, survival rate and body composition of the fish were measured. The results of this study showed that there was significant differences in the growth indices and body composition of the fish that were fed the different diets (P0.05). The survival rate was 100% in all treatments. There were no significant differences in body protein, lipid and ash contents in the different treatments (P>0.05), but significant differences were observed in the moisture content of the body of the fish that were fed different diets (P<0.05). The results of the present study suggest that 30% of fish rations can be replaced by canola rations without any negative effects on the growth rate, survival rate and body composition of the Siberian sturgeon

    Histological characterization of venom secretory cells in the stinger of 3 stingrays (Dasyatidae) species: Dasyatis bennetti, Himantura walga, Himantura gerrardi, in northern water of Persian Gulf and Oman Sea

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    Rays are common elasmobranches in the northern waters of Persian Gulf and Oman Sea that may have one or more mineralized serrated stingers on the whip-like tail. The stingers are covered by epidermal cells among which some can produce venom. When these animals are dorsally touched, the stinger may be introduced into the aggressor by a whip reflex mechanism, causing severe mechanical injuries and inoculating the venom. A comparative morphological characterization of the stinger epidermal tissue of different ray species in the northern part of Persian Gulf and Oman Sea was carried out in this study. EDTA was used for decalcification of stings and conventional histological processes were subsequently employed. The results indicated that structure of dermis and epidermis layers of stings in all species are similar to those of corresponding layers in other parts of fish’s body. The results of the present study have also shown that all three examined species, had venom secretory cells. Distribution of venom secretory cells varies in each species; in Dasyatis bennetti and Himantura walga species, these cells presented in all covered epithelium of stings and in Himantura gerrardi, were in the ventral, ventro-lateral and dorso-lateral of the spine. These differences among the stingers of various species may explain the envenomation severity in these species

    Surgical management of tibial plateau fractures with 3.5mmsimple plates

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    Background: Tibial plateau fractures can be successfully fixed utilizing 3.5mmlocking plates. However, there are some disadvantages to using these plates. Objectives: In the current prospective study, we investigated the outcome of treating different types of tibial plateau fractures with 3.5mmsimple plates which, to our knowledge, has not been evaluated in previous studies. Materials and Methods: Between 2011 and 2013, 32 patients aged 40-0.2 years underwent open reduction and internal fixation for tibial plateau fractures with 3.5mmsimple plates. The patients were followed for 16.14-2.1 months. At each patient's final visit, the articular surface depression, medial proximal tibial angle, and slope angle were measured and compared with measurements taken early after the operation. The functional outcomes were measured with the WOMAC and Lysholm knee scores. Results: The mean union time was 13-1.2 weeks. The mean knee range of motion was 116.8-3.3. The meanWOMACand Lysholm scores were 83.5-1.8 and 76.8-1.6, respectively. On the early postoperative and final X-rays, 87.5 and 84 of patients, respectively, had acceptable reduction. Medial proximal tibial and slope angles did not change significantly by the last visit. No patient was found to have complications related to the type of plate. Conclusions: In this case series study, the fixation of different types of tibial plateau fractures with 3.5mmsimple non-locking and non-precontoured plates was associated with acceptable clinical, functional, and radiographic outcomes. Based on the advantages and costs of these plates, the authors recommend using 3.5mmsimple plates for different types of tibial plateau fractures. Copyright © 2016, Trauma Monthly

    Iranian joint registry (iranian national hip and knee arthroplasty registry)

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    Periodic evaluation and monitoring the health and economic outcome of joint replacement surgery is a common and popular process under the territory of joint registries in many countries. In this article we introduce the methodology used for the foundation of the National Iranian Joint Registry (IJR) with a joint collaboration of the Social Security Organization (SSO) and academic research departments considering the requirements of the Iran's Ministry of Health and Education. ©BY THE ARCHIVES OF BONE AND JOINT SURGERY

    Iranian joint registry (iranian national hip and knee arthroplasty registry)

    Get PDF
    Periodic evaluation and monitoring the health and economic outcome of joint replacement surgery is a common and popular process under the territory of joint registries in many countries. In this article we introduce the methodology used for the foundation of the National Iranian Joint Registry (IJR) with a joint collaboration of the Social Security Organization (SSO) and academic research departments considering the requirements of the Iran's Ministry of Health and Education. ©BY THE ARCHIVES OF BONE AND JOINT SURGERY
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