جستجوی مقالات مرتبط با کلیدواژه "growth performance" در نشریات گروه "ریاضی"

Spirulina is a unicellular and filamentous blue-green algae that has gained considerable popularity in the health food industry and increasingly as a protein and vitamin supplement to aquaculture diets. It has long been used as a dietary supplement by people living beside the alkaline lakes, where it is naturally found. Spirulina has been used as a complementary dietary ingredient of feed for fish, shrimp and poultry. Among the various species of Spirulina, the blue green algae, Spirulina platensis has drawn more attention because it shows a high nutritional content characterized by 70% protein content and by the presence of minerals, vitamins, amino acids, essential fatty acids, etc. Spirulina is used because of its bioactive compounds that are able to enhance fish growth, protect against diseases, strengthen the immune system, stimulate hunger and enhance feed consumption, reduce stress and improve digestion by increasing secretion of different digestive enzymes. It also exhibits antimicrobial and antiviral properties. In the present study, we examined the effect of blue-green algae Spirulina platensis biomass on growth performance, secretions of digestive enzymes, blood physiological indices and resistance of grass carp, Ctenopharyngodon idella infected with Aeromonas hydrophila.

The production of live spirulina algae was done in Arka Algae Hyrcanian Company, Golestan Province, in a greenhouse environment with 2 long pools with dimensions of 12 m long, 2.5 m wide and 50 cm height. To enrich the pool, salt at the rate of 15 g/L, sodium bicarbonate at 16 g/L, and Zaruk culture medium were used according to the manufacturer's instructions. Then, 10 to 14 days after the storage of the initial stock, when the depth of the visible Secchi disc was about 2 cm, the harvesting operation was performed from the pool. To prepare the basic diet, items were prepared and ration balance was done with the UFFDA software. Chemical composition (protein, fat and ash) of formulated diet was measured according to AOAC method. Two hundred and forty fish (7.86 ± 0.47 g) were randomly distributed in 12 tanks (20 fish per 50 L). Also, together with the consumption of basic food (protein 32.29% and energy 3984.80 kcal/kg), different levels of spirulina algae were added with a concentration of 4 × 104, 5 × 104 and 6 × 104 cells/mL (S1, S2 and S3, respectively) and basic food without algae (C), daily to rearing tanks for 60 days. At the end of the test period, growth and nutritional performance, digestive enzyme activities, blood serum antibacterial activity against Aeromonas hydrophila bacteria, immune and antioxidant factors, and blood indices were measured. One-Way ANOVA test was used for data analysis and Duncan's multiple range test to check the difference in means (p<0.05).

The growth of fish in the treatments containing spirulina was significantly higher and the feed conversion ratio was lower compared to the control treatment. Highest protease and lipase activities were observed in S2 and S3 treatments, respectively. The highest blood serum immune response (lysozyme, complement and total immunoglobulin) was observed in S2 and S3 treatments. The lowest and highest concentrations of superoxide dismutase and malondialdehyde were obtained in the control. Bactericidal activity of fish serum was significantly higher in S2 and S3 treatments. The highest white and red blood cells, hemoglobin and hematocrit were observed at S3 treatment; meanwhile, the lowest value was obtained in the control.

In general, physiological parameters such as growth efficiency, digestive secretions, immunity and bactericidal activity of blood serum were improved in grass carp fed with live spirulina algae with a density of 5 × 104 and 6 × 104 cells/mL.

The high price of fish oil increases the cost of fish feed. So, using vegetable oils can significantly reduce its cost. Therefore, this study was investigated the effects of replacing fish oil with corn oil in the diet on the growth performance and biochemical composition of R. kutum fingerlings. In this study, twelve 100-L fiberglass tanks were used, each containing 20 fingerlings (6.05 ± 0.6 g in average weight and 7 ± 0.3 cm in average total length). The fish fed with four diets with the same protein, fat and energy including: T0 (control treatment), 25, 50 and 75% replacement of corn oil (T1, T2 and T3). The fingerlings were fed three times for 8 weeks and based on 3% of body weight. At the end of the experiment, growth rate, physical and chemical characteristics of water and biochemical composition of the carcass were measured. In this study, no statistically significant differences were observed between the treatments in terms of food conversion coefficient, protein efficiency coefficient, specific growth rate, body weight gain, length increase percentage, average daily growth, condition factor, survival rate, initial length, final length, initial weight and final weight (p>0.05). There was also no significant difference between the treatments in terms of carcass moisture and ash (p>0.05). However, significant differences were found in terms of the fish protein and fat among the treatments (p<0.05). Hence, the replacement of corn vegetable oil up to 75% with fish oil does not exhibit any negative effect on the growth performance of R. kutum.

Information on the aquaculture of rainbow trout Oncorhynchus mykiss in brackish water, especially in the Caspian Sea, is very limited. In this study, the growth performance and feeding efficiency of rainbow trout in an enclosed environment (5 floating cages) in an offshore farm (5 km distance from the beach) in the southern Caspian Sea region were investigated. This study was performed in Mehrangostar Caspian Sea farm in the Tuskatok area of Nowshahr City, Mazandaran Province, Iran. The fish were introduced to the cages with a density of 21 fish/m3 and also biomass of 3.33 kg/m3 and weight of 110 to 180 g. The duration of the rearing period and the average survival rate of fish were 123-158 days and 95.8 ± 0.5%, respectively.  In addition, the feed conversion ratio and protein efficiency ratio were 0.94 ± 0.01 and 2.66 ± 0.01, respectively. In this brackish farm, the fish average daily growth rate and the average specific growth rate were 3.3 ± 0.9 g/day and 1.07 ± 0.01%/day. Moreover, the average weight of fish yield was 16 kg/m3. The results showed that the growth trend of rainbow trout in the brackish water of the Caspian Sea in floating cages was suitable. Therefore, the introduction of rainbow trout to floating cages in the southern Caspian Sea by different weights, density of 3.33 kg/m3 and also by managing the harvest of 15 kg/m3 in different times or in a whole single catch is quite possible.

The aim of the present study is to investigate the effect of microalgae (Chlorella vulgaris) and brewer’s yeast (Saccharomyces cerevisiae) on growth performance, digestive enzymes activity and intestinal microbiota in sterlet juveniles (Acipenser ruthenus). Total number of 315 sterlet juveniles (24.5 ± 0.2g) were divided into 7 treatments and were fed with a basal diet containing different amounts of Chlorella and yeast during 8 weeks. Treatments 1 to 7 were fed with a basal diet supplemented with no chlorella and yeast (control), 1% yeast, 0.5% yeast, 3% Chlorella, 5% Chlorella, a combination of 0.5% yeast and 5% Chlorella and a combination of 0.5% yeast and 5% Chlorella, respectively. At the end of trial, growth factors, digestive enzymes and total number of intestinal bacteria were measured. The results showed that the addition of yeast and Chlorella to the fish diet improved growth performance, increased the secretion of digestive enzymes and also increased the number of intestinal bacteria compared to the control (p<0.05). The best growth performance was observed in treatments 5 (5% Chlorella) and then treatments 6 and 7 (combination of Chlorella and yeast) so that the highest amount of body weight gain, average daily growth, specific growth rate, and the lowest feed conversion ratio were observed in treatments 5, 6 and 7 (p<0.05). No significant difference was seen in the survival rate between treatments (p>0.05). The results showed that supplementing the diet of sterlet juveniles with microalgae and brewer’s yeast as well as their combination significantly improve the growth performance, secretion of digestive enzymes and intestinal bacterial flora.

The aim of this study was to compare the effects of adding taurine to diet as a mixture with feed and also as spray on growth and feeding performance, body composition and physiological responses of Asian sea bass, Lates calcarifer (13.62 ± 0.2 g). This study was carried out in a completely randomized design as three treatments with triplicates. Fish were fed with feed containing 0 (control group), 10 g/kg taurine in feed as mixture (treatment M) and 10 g/kg as spray on feed (treatment S) for 6 weeks. At the end of the experiment, final weight, weight gain, specific growth rate and feed conversion ratio were significantly higher in treatment S compared to the control and treatment M (p < 0.05). Carcass fat and moisture contents significantly varied in treatment M with the control and with treatment S (p < 0.05). However, carcass protein value was not influenced by supplemented tuarine (p>0.05). The obtained results indicated that dietary taurine did not enhance Asian sea bass blood biochemical factors and non-specific immune response (p>0.05). Overall, it can be concluded that feeding Asian sea bass with the diet supplemented by 10 g taurine as spray for a period of 6 weeks enhances the growth and feeding performance.

 The aim of this study was to investigate the effect of chitosan nanoparticles containing folic acid in the diet of rainbow trout, Oncorhynchus mykiss on growth and survival indices. For this purpose, rainbow trout with an average weight of 30 ± 2 g were divided into five experimental treatments: 0, 0.1, 0.25, 0.5 and 1 mg of chitosan/folic acid nanoparticles per kg of diet. Each treatment containing 25 fish in 3 repetitions in 15 tanks (500 liter) was designed into a closed-circuit breeding system. After making a manual diet and adapting the fish to the new conditions they were fed for 8 weeks. At the end of the experiment period, growth and survival indices were evaluated. The highest growth rate was recorded in the treatment of 1 mg/kg of chitosan/folic acid nanoparticles at the rate of 69.23 ± 4.34 g. With increasing Ch/FA nanoparticles levels in the formulated diets, the feed conversion ratio decreased linearly, which in fish fed with 1 mg/kg diet supplemented with chitosan / folic acid nanoparticles reached to 1.29 ± 0.08 (p < 0.05). On the other hand, the survival rate was the same in all treatments, but at the end of the period, losses were clearly observed in the control. The results showed that increasing the level of chitosan/folic acid nanoparticles in formulated diets will increase the growth rate and have a positive effect on growth index.

This study was conducted to evaluate the effect of different levels of canola oil on growth performance and survival of Caspian salmon fry (Salmo trutta caspius) during replacement with canola oil over a period of 60 days. 180 fish fries (4.25 ± 0.68 g) with a density of 15 were distributed and introduced to 300 liter fiberglass tubs. For this purpose, 4 treatments with 3 duplication, diets including 100% fish oil, 100% canola oil, 50% fish oil and 50% canola oil, 70% fish oil and 30% canola oil (with the same protein and fat levels of 43 and 14%, respectively) were applied. The results showed that the highest weight (26.46 g), final length (13.46 cm) and specific growth rate (2.97%) were belonging to the treatment containing 50% fish oil and 50% canola oil which showed a significant difference with other treatments (p≥0.05). Moreover, the lowest value of feed conversion ratio (1.41) and the highest amount of status factor (0.09 ± 1.08) were also related to treatment 3, but these differences were not statistically significant (p≥0.05). The highest protein efficiency coefficient of 2.37 was related to the treatment containing a mixture of 70% fish oil and 30% canola oil, which showed a significant difference with other treatments (p≤0.05). The survival rate among all treatments was 100% (no losses). Based on the results, it can be concluded that the replacement of part of fish oil with canola oil (50% fish oil with 50% canola oil) in the diet of Caspian salmon not only has no negative impact on growth factors and survival of Caspian salmon, but also it will improve these factors and can decrease costs by reducing the length of the culture period.

This study was carried out to determine the effects of Echinacea purpurea extract on growth indices, hematological indices and innate immunity of Siberian sturgeon (Acipenser baerii). So, 120 of Siberian sturgeon with an average weight of 53.12 ± 0.08 g were divided into four groups with three replicates. The fish were fed with experimental diets containing 0, 0.5, 1 and 1.5% (T0%, T0.5%, T1% and T1.5%, respectively) E. purpurea extract for eight weeks. The results of this study showed that T1.5% had the highest final weight, weight gain, specific growth rate and condition factor (p < 0.05). The best feed conversion ratio was also observed in T1.5% (p < 0.05). In hematological examinations, results also exhibited enhancement in all indices including white and red blood cells count, hemoglobin, hematocrit and hematological indices in all treatments and the best results were observed in T1.5% (p < 0.05). Significant differences were found in innate immunity indices between the experimental treatments (p < 0.05). The highest levels of lysozyme, complement and respiratory burst activities were found in T1.5%. According to the results, adding 1.5% E. purpurea to fish diet can improve growth rate, hematological indices and innate immunity of Siberian sturgeon

Jewel fish (Hemichromis bimaculatus)is a well-known and market-freindly ornamental fish in Iran. This work aimed to investigate the effects of caraway(Carum carevi)as a plant extract on growth, blood and immune indices in jewel fish in an 8-week period. So, 120 fish (5 g in weight) were distributed in 12 aquariums. A control group and 3 treatments were considered as follows: control group fed diet with no supplementation, treatment 1 (0.5%), treatment 2 (1%) and treatment 3 (1.5% caraway) in 3 replicates. Immunological and biochemical indices as well as growth performance were measured during the experiment. Among the growth indices, there was the best performance of SGR, PBWI, CF and FCR in treatment 2, exhibiting significant differences (p<0.05) with other groups. In additoin, treatment 2 displayed better results in terms of hemological indices. So that, the highest number of red blood cells, hemoglobin, hematocrit, MCHC, IgM, total protein, lysozyme, total immunoglobulin and HDL cholesterol were observed in treatment 2, exhibiting significant differences (p<0.05) with other groups. Therefore, it was found that adding 1% caraway to the diet can elevate the efficiency of immune system and also enhance the growth and nutritional indices in jewel fish.

This study aimed to evaluate the effects of different levels of microencapsulated antioxidant supplementation (Nano-selenium, Vitamins E and C) on growth performance, body composition and some blood biochemical indices in rainbow trout, Oncorhynchus</em> mykiss</em>. Fish with an average weight of 9.07 ± 0.36 g were distributed into 12 tanks and divided into four experimental groups: treatment 1 (N-Se; 0.1, E; 30 and C; 100 mg/kg), treatment 2 (N-Se; 0.2, E; 60 and C; 200 mg/kg), treatment 3 (N-Se; 0.3, E; 90 and C; 300 mg/kg) and commercial diet as control. The results exhibited that the fish fed with diets containing additional microencapsulated antioxidant supplementation induced higher final growth, weight gain, the protein and lipid efficiency ratios, while had no different in feed conversion ratio. The body composition such as protein and lipid did not exhibit significant differences between the treatments. The serum lysozyme activity and superoxide dismutase enzyme were significantly elevated in fish fed with supplemented diet compared to the control. The alanine aminotransferase and alkaline phosphatase significantly increased in the three treatments whereas aspartate aminotransferase reduced in fish fed with antioxidant supplementation compared to the control. The present results indicated the beneficent effects of microencapsulated Nano Se and vitamins E and C on growth rate and immune response in rainbow trout.

This study aimed to introduce new protein sources to replace fish powder in diets for rainbow trout, Oncorhynchus mykiss. In this study, fish powder protein was replaced with the typical Kabuli chickpea (Cicer arietinum) and irradiated pea seeds in the diet followed by assessing their effects on growth and nutritional indices, digestion and body composition of rainbow trout. The study was conducted in the Artemia and Aquatics Propagation Research Institute, University of Urmia, Urmia, Iran. 720 juvenile O. mykiss (60 ± 4 g) were randomly divided equally into eight treatments with three replicates, and were fed with experimental diets for 60 days. The experimental diets were commercial food, homemade food without pea (control), typical pea diets containing 20, 30 and 40% and diets containing 20, 30 and 40% irradiated pea. The results showed that radiation has not significantly affected the food ingredients of peas (protein, fat and dry matter) and growth parameters (P>0.05), but there were significant changes in nutritional indicators and digestibility of the diet along with increasing the percent of peas replacement (P<0.05). As a result, the increase in radiation as well as 40% peas in the diet of O. mykiss did not exhibit negative impact on growth performance. Therefore, the irradiated pea protein can be a good food item to replace fish powder in the fish diet.

This study aimed to introduce new protein sources to replace fish powder in diets for rainbow trout, Oncorhynchus mykiss. In this study, fish powder protein was replaced with the typical Kabuli chickpea (Cicer arietinum) and irradiated pea seeds in the diet followed by assessing their effects on growth and nutritional indices, digestion and body composition of rainbow trout. The study was conducted in the Artemia and Aquatics Propagation Research Institute, University of Urmia, Urmia, Iran. 720 juvenile O. mykiss (60 ± 4 g) were randomly divided equally into eight treatments with three replicates, and were fed with experimental diets for 60 days. The experimental diets were commercial food, homemade food without pea (control), typical pea diets containing 20, 30 and 40% and diets containing 20, 30 and 40% irradiated pea. The results showed that radiation has not significantly affected the food ingredients of peas (protein, fat and dry matter) and growth parameters (P>0.05), but there were significant changes in nutritional indicators and digestibility of the diet along with increasing the percent of peas replacement (P<0.05). As a result, the increase in radiation as well as 40% peas in the diet of O. mykiss did not exhibit negative impact on growth performance. Therefore, the irradiated pea protein can be a good food item to replace fish powder in the fish diet.

In this study, the effects of probiotics bacilli on the feed efficiency and carcass quality in rainbow trout, Oncorhynchus mykiss, fries were studied using a commercial product Protexin Aquatech. A blend of five strains of probiotic bacilli (Basilus licheniformis, B. subtilis, B. polymyxa, B. laterosporus and B. circulans) was used through the supplementation of diets for 60 days. Fish fry with an average weight of 463 ± 32 mg were used. The experimental diets were supplemented with mixture of the five bacilli at concentrations of 1×106 (D1) 1×107 (D2) and 1×108 (D3), (CFU per 100 g food), and a control (probiotics-free diet). The feeding rate was varied between 5 and 8% of body weight. The results indicated that D2 treatment had significantly better growth and feed conversion ratio than the control group and D1 treatment. Results showed that in the experimental treatments, probiotics had a significant positive effect on protein efficiency ratio, lipid efficiency ratio and protein productive value compared to the control treatment (P