فهرست مطالب abdolmohammad abedian kenari

The use of probiotics and organic acids is an ideal and suitable alternative to antibiotics in aquaculture. Currently, there is not enough knowledge about the specific and combined effects of these additives in the diet of sturgeon. Therefore, the aim of this research was to evaluate the use of lactic acid and probiotic supplements (Protexin) and their combination in the diet of Siberian sturgeon (Acipenser baerii). Therefore, 160 healthy fish with an average body weight of 54.85 ± 0.36 grams were randomly divided into 4 experimental groups in 3 replicates. Fish were fed four diets including a control diet without additives (diet 1), a control diet with 2% lactic acid (diet 2), a control diet with a combination of 2% lactic acid and 0.01% Protexin (diet 3), and a control diet with 0.01% Protexin (diet 4). Fish were fed three times a day to satiation for 9 weeks. At the end of the experiment, growth and physiological parameters were measured. The results showed that lactic acid alone and in combination with Protexin increased body weight and specific growth rate. The feed conversion ratio decreased in treatments where lactic acid was used alone or in combination with Protexin (P<0.05). Mortality rates were zero in all treatments during the experimental period. The carcass protein of Siberian sturgeon in diets supplemented with a combination of lactic acid and Protexin showed significant improvement compared to other groups (P<0.05). Addition of lactic acid and Protexin either separately or in combination led to a decrease in carcass fat content (P<0.05). The lowest intestinal pH was observed in the diet supplemented with lactic acid along with Protexin, while the highest was in the control group. Additionally, the total number of lactic acid bacteria in the intestines of fish fed with lactic acid along with Protexin showed a significant increase compared to other treatments (P<0.05). The combined addition of lactic acid with Protexin significantly increased lysozyme and complement activity in fish blood (P<0.05). In general, the separate and combined use of lactic acid (2 %) and Protexin (0.01 %) in the diet of Siberian sturgeon improved the performance of this fish.

In this experiment fish meal was replaced with RPC by levels of 0, 25, 50, 75, and 100%. Diets fed to kutum (initial weight of 340±20 mg) three times daily for 60 days. The highest final weight (1020 mg) and weight gain (670 mg) and the lowest FCR (1.5) were observed in the 50% substitution treatment, which was significantly different from the other treatments (P < 0.05). The survival rate was 100% and the same for all diets. No significant difference was observed in carcass composition (moisture, protein, lipid and ash) between different treatments (P > 0.05). By increasing the amount of rice protein concentrate, the amount of n-3 decreased and the amount of n-6 increased (P<0.05). The ratio of n-3 to n-6 did not change significantly up to the level of 25%, but it showed a significant decrease with the increase of the substitution level. The amount of total amino acid did not change significantly among the treatments with the increase in the concentration level. The highest amount of essential amino acids was related to the 25% treatment, which was significantly different from the control, 50, 75 and 100% replacement treatments. In general, the results of this study showed that rice protein concentrate can be used as a substitute for fish meal up to 50% in the diet without significant change in the growth of Kutum fry. Of course, the quality of carcass fatty acids was not maintained at this level, and the 25% level was more suitable.

The aim of this study is to investigate the changes in fatty acid composition in Nannochloropsis oculata microalgae under physicochemical stresses (light intensity and salinity). In this regard, the growth rate, the amount of chlorophyll and carotenoid, the approximate analysis and the profile of fatty acid changes of marine microalgae N. oculata under two mutual stresses of salinity (15, 25 and 40 g/l) and light intensity (Lux 1500 and Lux 10000) which at the end of the phase Logarithms were applied are examined. The results showed that according to the application of stresses after the completion of growth, there was no significant difference in the growth rate in different treatments (P>0.05). Also, despite the fact that the highest amount of lipid was obtained under the salinity treatment of 40 g/l and the light intensity of Lux 1500, the highest amount of saturated fatty acids (SFA) was obtained under the treatment of salinity of 15 g/l and the light intensity of 10000 Lux, the highest amount of monounsaturated fatty acids (MUFA) under 25 g/l treatment and 10000 Lux light intensity and the highest amount of polyunsaturated fatty acids (PUFA) under 15 g/l treatment and 10000 Lux light intensity were obtained after 4 days of stress. Considering the effectiveness of fatty acid compounds in N. oculata microalgae, by controlling the cultivation conditions, the maximum amount of desired fatty acids can be achieved in accordance with the desired goals.

This experiment evaluated the effect of soluble polysaccharides in Spirulina platensis microalgae on growth performance, body composition and immune response of rainbow trout (Oncorhynchus mykiss). In this regard, 180 rainbow trout (17.22 ± 0.5g) were selected and distributed in five experimental treatments (with three replications). Treatments included different levels of polysaccharide in dosage of 0 (control), 500, 1000, 2000 and 3000 mg / kg of feed. According to the results, in growth factors (final weight, body weight gain, specific growth factor, protein efficiency, feed conversion ratio and condition factor), no significant difference was observed. The highest and the lowest amount of carcass proteins were observed in the diet containing 500 mg polysaccharide and control, which showed a significant difference. The amount of fatty acids of the muscle of the fish body did not show any significant difference among the treatments. The highest and lowest levels of lysozyme activity were observed in treatments of 2,000 mg polysaccharide and control and the highest and lowest levels of complement activity were observed in treatments containing 3000 mg polysaccharide and control respectively (P <0.05). In general, the use of polysaccharide extracted from micro-algae did not significantly improve rainbow trout growth, but a slight improvement in growth and body composition (protein) in 500 mg polysaccharide per kg of diet was observed. In terms of safety indicators, treatments of 2,000 and 3,000 mg of polysaccharides per kg of diet had a good performance and could be used whenever needed.

In this experiment, head wastes were prepared and enzymatically hydrolyzed using alcalase (2.4 L) enzyme. The hydrolysate was fractionated by ultrafiltration with 10 kDa molecular weight cut-offs and the desired fraction was encapsulated following ion coagulation method (chitosan and triphosphate (TPP)) in nanochitosan capsules. Encapsulation process was optimized based on different ratios of chitosan:TPP and different concentrations (1, 5 and 10 mg/ml) of peptidic fraction. Finally, the degree of hydrolysis and the length of the peptides obtained from enzymatic hydrolysis were determined. The nanocapsules were examined for size, zeta potential and polydispersity index (PDI) using dynamic light scattering (Malvern, England). Structural and surface morphology studies including scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) of capsules produced under favorable conditions were also performed. Particle size was measured in various concentrations and treatments in the range of 30 to 150 nm. The best results were obtained in the treatment of 2: 1 ratio of chitosan to polyphosphate and concentration of 10 mg / ml. The size, dispersion index, zeta potential and size of nanocapsules in the optimal conditions were 0.375, 2020 and 30.13 nm, respectively, and storage conditions at -20 °C had no effect on the quality of nanocapsules. Based on the efficiency study, it was found that fraction with a concentration of 10 mg/ml is well encapsulated by chitosan with an efficiency of 91.04 ± 0.18 percent. The results showed that chitosan-TPP could be used for nanocapsulation of bioactive peptides with an approximate molecular weight of less than 10 kDa.

The effect of different levels of fucoidan on fatty acid profile and growth of rainbow trout were investigated. 150 fish (average weight 18.84 ± 70.7) were distributed in 15 fiberglass tanks (100 liters) and fed for 8 weeks at different levels (0 (control), 0.1%, 0.5%, 1% and 2% fucoidan). The results showed that the treatment with the highest amount of fucoidan had the highest final weight, specific growth rate and body weight gain, and there was a significant difference between treatments (p <0.05). There was no significant difference between feed conversion ratio and different treatments (p> 0.05). The difference between EPA, DHA, SFA, MUFA, n-3, HUFA and ratio of n-3 to n-6 was not significant (p >0.05), while PUFA and Arachidonic acid significantly different between treatments (p <0.05) and the highest value was observed in in treatment 2 and 1% respectively. Based on the results of this study, it can be concluded that this type of Polysaccharide at high doses (1 and 2% of fucoidan) can improve the growth performance and maintain the quality of muscle fatty acids.

The present study was conducted to examine singlular and combined effects of manan oligosacharid (MOS) and L. plantarum supplements on growth indices and hematological parameters of Caspian trout (Salmo trutta caspius Kessler, 1877). Caspian trout fingerlings (~ 10 g) were fed with a control diet (basal diet) or supplemented diets as follows: 1) the basal diet + 4g kg−1 IMOS, 2) the basal diet + -8×108 CFU/g-1  L. plantarum)  and 3) a synbiotic diets (the basal diet + 8×108 CFU/g-1  L.plantarum + 4g kg−1IMOS) for 8 weeks. At the end of this trial, the results of the MOS supplemented and synbiotic diet showed significant increase in feed conversion ratio (FCR), weight gain (WG), feed intake (FI), protein efficiency ratio (PER), specific growth ratio (SGR) and daily growth index (DGI) compared with fish fed the control diet (p<0.05). The highest FCR and FI were observed in the control group. In the case of condition factor, the singlular and combined diets showed no significant differences (p>0.05). The results of blood indices among all treatments revealed significant differences of the number of red blood cells (RBC) compared to the control group (p<0.05). The highest and lowest number of RBC was found in L. plantarum diet and control group, respectively. The number of white blood cells (WBC) showed no significant differences with control group (p>0.05). The results demonstrated that the MOS-supplemented diet and the combined diets containing MOS and L. plantarum improved the growth performance in Caspian trout fingerlings.

In the present study, the apparent digestibility of protein and amino acids of ten types of plant and animal feed ingredients as the main sources of protein was evaluated in the Siberian sturgeon diet (290±22g). 

Materials & Methods

Feedstuffs included fish meal, meat and bone meal, poultry by-product meal, blood meal, feather meal, soybean meal, rapeseed meal, wheat gluten, corn gluten, and bakery yeast. The dietary treatments included reference diet and ten different experimental rations (30% of the target feed ingredient and 70% of the reference diet). Chromic oxide was used as an indigestible marker in dietary feed. A group of 165 Siberian sturgeons stocked into 33 tanks with 500 liters volume and fed with test diets (3 replicates per diet).

At the end of the experiment, the highest and lowest protein digestibility was observed in ϐish meal (92.87%) and poultry by-product meal (59.96%), respectively. Also, the highest level of amino acid digestibility in fish meal was measured (90.9% and 88.13% for total essential and non-essential amino acids, respectively). The lowest digestibility of the essential amino acids was reported in rapeseed meal (65.5%) and non-essential amino acids in poultry powder (60.68%).

Fish meal, meat and bone meal, poultry by-product meal, corn gluten, and wheat gluten were identified as feed ingredients with high protein and amino acids digestibility for Siberian sturgeon.

Animal protein sources in fish feeds are expected to be greatly decreased as a consequence of increasing economic، environmental and safety issues. Research for fish nutrition has recently focused on the development of practical diets with minimal levels of fish meal and alternative lower-cost protein sources. At the present study، primarily، rice bran protein concentrate (RBPC) was produced with alkalinity method and، then، were used in rainbow trout diets at three levels (10، 25 and 35%) as a fish meal replacement. One diet was taken as control without replacing. Alvine fed these diets for 30 days after the start of feeding. The survival was significantly (P<0. 05) higher in control but there was no significant difference among others (P>0. 05). High final weight and weight gain and SGR were observed at the end of trial for RBPC-10 diet (P<0. 05). The highest and lowest of PER and LER was observed in control and RBPC-35 groups، respectively. But these factors had no significant difference between RBPC-25 and RBPC-10 (P>0. 05). Based on a proximate analysis، the groups fed RBPC-35 showed lower protein and higher lipid in body composition (P<0. 05). Results of amino acid profile of fishes fed plant protein showed that the amount of Glysine increased at 25 and 35% of RBPC. Also، histidine decreased at all diets compared to the control. The lowest amount of lysine was found at RBPC-35. In conclusion، fish meal can be substituted with up to 25% RBPC in larval stage of rainbow trout without any growth reduction.