18 research outputs found

    Regulation of the Duration of Spawning Cycles of Catfish in Industrial Aquaculture

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    This article is devoted to the study of the qualitative and quantitative characteristics of the African Catfish Clarias gariepinus eggs produced at different durations of the inter-spawning interval. Eggs were produced artificially using sex hormones. In industrial aquaculture, the African Catfish Clarias gariepinus does not reproduce naturally. Therefore, the problem of obtaining high-quality eggs that will be used for in-vitro fertilization is urgent. To implement artificial spawning of fish in industrial aquaculture, it is necessary to correctly choose the effective hormonal stimulator and empirically select its dose. Sex hormones are involved in regulating the duration of the inter-spawning interval and affect the quality of eggs produced both for fertilization and for food purposes. The pituitary gland of the African Catfish Clarias gariepinus and surfagon were used as gametogenesis stimulators. The aim of the work was to study the optimal duration of the inter-spawning interval and the effect of hormonal inducers used to stimulate artificial spawning in industrial aquaculture. The use of the catfish pituitary gland in fresh or acetonated form as a hormonal stimulator provided higher-quality eggs, compared to the synthetic hormonal drug - surfagon. Stimulation with acetonated pituitary injections reduced the inter-spawning interval of the African Catfish Clarias gariepinus to three months, and the use of surfagon prolonged the inter-spawning interval to four months. Reducing the duration of the inter-spawning interval is important for the production of the African Catfish Clarias gariepinus eggs for food purposes. Studies have shown that reducing the optimal duration of the inter-spawning interval negatively affects the quality of the produced eggs and their quantity. This research was financially supported by a grant from the Russian Foundation for Fundamental Research, project No. 18-016-00127. Keywords: aquaculture, African Catfish Clarias gariepinus, eggs, inter-spawning period, sex hormones, oocyte

    The content of nutrients and biogenic elements in enriched artemia salina

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    The work is devoted to the development of technology for enriching artemia with biologically active substances. The development of technology for enriching artemia with biologically active substances is important as an opportunity to obtain starter feeds for aquaculture with the desired properties. High content of high-grade protein, vitamins, amino acids, fatty acids, biogenic elements is of great importance. During artificial cultivation of artemia in a closed cycle in the conditions of aquaculture, there is a problem of sufficient accumulation of substances in its body that provide high nutritional and biological value. To solve this problem, we have developed a technology for enriching artemia with biologically active substances at the nauplium stage. The enrichment of artemia with vitamins, amino acids, probiotics, adaptogens, essential lipids allows us to create a new generation of bio-feeds containing a living symbiotic microbiota and ingredients capable of forming balanced complex of functional nutrition for fish. The aim of the study was to evaluate the biological and energy value, the content of proteins, fats, carbohydrates, moisture, ash, micro- and macroelements, heavy metals in artemia at different stages of ontogenesis against the background of its enrichment with a complex of biologically active substances. Intact and enriched cysts, intact and enriched decapsulated artemia eggs, enriched artemia nauplii were analyzed. It was found that against the background of enrichment with biologically active substances, the indicators of metabolic energy increased, the mass fraction of crude protein, the mass fraction of fat and the content of minerals and biogenic elements increased

    Corrective effect of probiotics on the work of the fish body in industrial aquaculture

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    Abstract. The world community associates the solution of the problem of food security with the development of aquaculture. The search for means of intensifying the production of a complete and easily digestible food protein in aquaculture is an important and urgent problem. Recently, probiotics, which have long been in demand in medicine, have been used in aquaculture to improve health, accelerate growth and improve the quality of fish in aquaculture. However, the correct choice of a probiotic for aquaculture is not an easy task, since in the modern world a wide range of probiotic preparations is produced in various forms, the dosage of which for aquaculture needs has not been developed, as well as the dosage and duration of their use have not been developed. Meanwhile, the use of probiotics in aquaculture can be expected to increase the production of marketable fish of improved quality. Probiotics for aquaculture should be resistant to gastric juice, able to colonize the intestines of fish, interact with the normobiota of the intestine and suppress pathogens. These properties are possessed by the probiotic "Sporotermin". It consists of freeze-dried spores of the bacteria Bacillus subtilis and Bacillus licheniformis. The content of viable spores in the preparation is not less than 3x10/9 CFU/g. The research results showed that the use of the probiotic "Sportermin" in aquaculture has a healing effect on fish, normalizes the structure of intestinal and liver tissues, affects the leukogram, activates the immune response system, reduces the level of oxidative stress, activating antioxidant defense enzymes and reducing the level of malondialdehyde. The research was carried out on the instructions of the Ministry of Agriculture of the Russian Federation

    Features of artemia salina ontogenesis in aquaculture depending on the salt level

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    The work is devoted to the study of influence of salinity level at the rate of hatching, productivity and morphometric parameters of artemia in aquaculture. The cultivation technology of Artemia salina in aquaculture for obtaining live starter feeds has been used in practice for a long time, but it is still far from perfect, since it is developed for a certain averaged artemia, and in practice we have to deal with specific species and their ecomorphs (ecological morphotypes), the optimal conditions of cultivation of which differ in many ways. One of the most important factors determining the development of artemia is the salinity of the environment. The aim of our study was to assess the effect of the salinity level of culture medium at the rate of hatching, productivity and morphometric parameters of artemia grown in industrial aquaculture. The results of the study showed that with an increase in the concentration of salt in the solution for cultivation of artemia, metamorphosis of the free embryo in nauplia is prolonged and the percentage of their yield decreases. Differences in the average population indicators of length and body weight of nauplia were found, which tended to decrease with an increase in water salt concentration. When studying the absolute fertility of female artemia grown at different concentrations of salt, it was found that an increase in water salinity in reproductive age of females makes it possible to increase their absolute fertility when breeding in artificial conditions

    The composition of monounsaturated fatty acids of artemia enriched with biologically active substances

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    The work is devoted to the study of monounsaturated fatty acids (MUFA) content in artemia enriched with biologically active substances at different stages of ontogenesis. Artemia cysts are used in the preparation of dietary supplements, highly effective feed additives for farm animals, fertilizers for crop production, chitosan for pharmaceutical industry and cosmetology, as raw materials in many other fields. When growing fish, crustaceans, shellfish in aquaculture, artemia nauplii are used as live starter feeds, which are obtained in situ when cultivating artemia cysts. Recently, the direction of enrichment of artemia nauplia used for feeding fish larvae and fry with biologically active substances has begun to develop: vitamins, essential amino acids, essential fatty acids, probiotics. In our work, we used a feed additive for the enrichment of artemia nauplia, including: vitamin-amino acid complex – «Chiktonic», probiotic – «Vetom-1», adaptogen – «Trekrezan», hemp oil. Enrichment was carried out through the skin at the stage of early nauplia. The aim of the work was to study the composition of MUFA at different stages of ontogenesis in intact artemia and artemia enriched with biologically active substances. The main function of MUFA is to activate metabolic processes and maintain homeostasis. When identifying monounsaturated fatty acids of artemia, the race we studied, the following were identified: oleic, palmitoleic, eicosenic, elaidic, erucic, nervonic, myristoleic acids. Oleic, palmitoleic and eicosenic fatty acids played a dominant role in the structure of MUFA. Two fatty acids, erucic and elaidic, can be distinguished in the composition of MUFA, the content of which was minimal

    Reproductive Aging of African Catfish in Aquaculture

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    The work is devoted to the study of reproductive aging of African catfish in the conditions of industrial aquaculture. The problem is urgent, because industrial aquaculture changes the biology of African catfish so much that it loses its ability to reproduce naturally. The offspring of African catfish can be obtained only with the use of hormonal inducers of gametogenesis. Questions of age selection of producers and age composition of breeding stock in this type of fish are still open. In practice, we have to face the facts of poor quality of sexual products in primary spawning or old females and males. The aim of the study was a comparative assessment of age-related variability of reproductive properties of female and male African catfish in the conditions of industrial aquaculture. The results of our study showed the presence of age-related dynamics in the quality of sexual products in African catfish. Age-dependent differences in the quality and fertilization of eggs, the viability of embryos and larvae, their size, and the quality of offspring were established. When studying the properties of sexual products in fish of different ages, differences in morphometric and physiological parameters were found for a complex of indicators such as the size and diameter of eggs, sperm concentration, and the number of viable spermatozoa. Evaluation of the influence of parents age on the viability of offspring in the embryonic and postembryonic periods revealed that this indicator is the lowest in first – spawning fish, and the highest in middle-aged fish. The Russian Foundation for Basic Research has supported our study with the grant No. 18-416-730005

    Efficiency of Using Natural Zeolites in Cultivation of African Catfish

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    The article represents the results of studies in zeolite use in fish feeding. The influence of zeolites on the exterior and interior characteristics of African catfish grown in high-technological industrial aquaculture was evaluated. Zeolites were introduced into fish feed in the amount of 3 % and 5 %. The use of zeolites in feeding of African catfish has had a positive impact on the growth, exterior and interior indicators of fish. In five-month-old catfish, when using zeolites, the average daily growth increased by 4.15 g (with 3 % addition of zeolites) and by 4.68 g (with 5 % addition of zeolites), compared to fish that did not receive zeolites. In the experimental groups, there was also an increase in absolute growth by 124.4 g-with 3 % addition of zeolites and 140.2 g-with 5 % addition of zeolites. The commercial weight of fish using zeolites increased by 24.05 % and 35.52 %, respectively. The results show that when growing commercial fish, the use of zeolites in the feed composition fastens its growth and significantly reduces feed costs.

    The influence of the food factor on the components of the antioxidant protection system in fish

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    Functional feeding complexes that correct metabolic processes in animal bodies, increasing their productivity and preventing infectious diseases are a new direction in the development of modern feed production. Such feeds, thanks to a set of components, have a wide range of healing effects. We have developed a feed additive consisting of probiotics, adaptogens, vitamins and amino acids. The aim of the work was to study the effect of a new feed additive on the antioxidant system of fish. During the research, it was found that the content of glutathione (GSH) in male fish raised on the background of biologically active feed additive doubled, and in females by more than 30%, and the activity of glutathione-S-transferase also increased. Therefore, on the background of the use of new biologically active feed additive, the resistance of the fish body to free radical and peroxide processes increases

    Evaluation of the content of polyunsaturated fatty acids in artemia at different stages of ontogenesis

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    The work is devoted to the study of the composition of polyunsaturated fatty acids (PUFA) at artemia of different stages of ontogenesis. The content of PUFA in intact cysts and decapsulated artemia eggs was studied, and the content of PUFA after enrichment of cysts, decapsulated eggs, and artemia nauplia with a multicomponent complex of biologically active substances was also studied. The composition of the enriching complex included probiotics, adaptogens, vitamins, amino acids and hemp oil. The results of the research showed that the use of the enriching complex significantly increased the content of polyunsaturated fatty acids of the omega–3 and omega-6 families. The content of eicosapentaenoic, docosahexaenoic, linolenic fatty acids from Omega-3 family, and the content of linoleic and arachidonic acids from Omega-6 family increased to the greatest extent, primarily in nauplia, decapsulated eggs and artemia cysts, thereby significantly increasing their biological and nutritional value while using as starter feeds for fish

    Effects of Bacillus subtilis and Bacillus licheniformis on catfish in industrial aquaculture

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    When growing fish in high-tech breeding systems, it is exposed to many stress factors. To reduce stress, we used spore forms of microorganisms — Bacillus subtilis and Bacillus licheniformis, possessing probiotic properties. Two groups were formed, a control group and an experimental group that received probiotic microorganisms with feed. The aim of the study was to evaluate the effectiveness of the use of microorganisms — Bacillus subtilis and Bacillus licheniformis to reduce stress in fishes. For this indicator points were selected — stress hormone cortisol and antioxidant defense enzymes. The research results showed that stress level assessed by cortisol in fishes fed with probiotic microorganisms is 2.8 times lower than in the control group. The use of micronucleus test to assess cytogenetic damage showed that against the probiotic microbiota background, the number of cells with fragmented nuclei decreases by 5.7 times. Antioxidant defense enzyme activity when using Bacillus subtilis and Bacillus licheniformis increased, indicating activation of the defense system against oxidative stress. The obtained results demonstrated the high efficiency of the use of spore forms Bacillus subtilis and Bacillus licheniformis when growing catfish in high-tech fish farming systems. The Russian Foundation for Basic Research has supported our study with the grant No. 18-016-00127
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