The aim of the work is to analyze the survival strategy of Taxus baccata L., one of the promising plants for landscaping and the creation of woodlands, in the changing ecological conditions of the steppe zone of the Donetsk ridge. In order to achieve this goal, we used biomechanics methods, which help to understand the relationship between the physical and mechanical properties of living tissues and the overall stability of trees during interactions with environmental factors such as temperature, snow and ice storms, cyclic freeze–thaw processes, wind loads, and others. The work was based both on experimental studies on the estimation of the tissue elasticity modulus in response to temperature changes, the mechanical stability of plants, the field collection of materials, and studies on the modeling of forest stand conditions of English yew. As a result of the conducted experiments, it was established for the first time that at the absolute wood moisture content of 77 ± 5.1%, the density of wood tissues in the conditions of Donetsk is 907 ± 43 kg m⁻³. The modulus of elasticity of living tissues depending on the temperature factor varied in the following range: 8.8 ± 0.31 GN m⁻² (T = 288 K), 11.5 ± 0.55 GN m⁻² (T = 255 K) and 6.9 ± 0.47 GN m⁻² (t = 308 K). It was revealed that during the local thawing of skeletal branches and tables, the mechanical resistance of T. baccata is reduced by 20–22% and this critically affects the overall plant resistance. It was established for the first time that T. baccata in the conditions of the steppe zone has an adaptive strategy of preserving the integrity of the organism under the action of environmental factors with limited loads. The secret lies in the formation of the shape memory effect, under the influence of critical loads. The plant, thus, chooses not migration, not death, but adaptation to changes in environmental conditions, which can become a serious factor in the use of T. baccata in the landscaping of urban areas and the creation of artificial forests.

Background.The selection of optimal feed formulations is a primary factor determining the efficiency and sustainability of aquaculture. The Australian Red Claw Crayfish,Cherax quadricarinatus(von Martens, 1868), known for its high growth rates and tolerance to water quality parameters, is a popular aquaculture species worldwide. However, the development of specialized feeds for this species remains insufficiently addressed. In practice, prepared feeds for other crustaceans or for sturgeon are commonly used for its cultivation. In natural habitats, the diet of this crayfish consists primarily of macrophytes (up to 87.5%) and detritus (42.8%), with the proportion of the plant component increasing with body size. The omnivorous feeding type creates opportunities for finding cheaper protein sources compared to fishmeal. Analysis of scientific research has shown that black soldier fly larvae and yellow mealworm can be used as alternatives to fishmeal in feeds for the Australian crayfish. Among plant-based raw materials, soybean, rapeseed, and peanut meal are unsuitable components. The specific feeding behavior of the Red Claw Crayfish necessitates sufficient stabilization and binding of feed pellets. Furthermore, the shape of the feed pellets must be considered, with the prism shape being the most preferable. Developing feed formulations that account for the biological specifics of the Red Claw Crayfish will enhance the efficiency of its aquaculture and reduce costs for farmers. Purpose.To identify the main dietary characteristics and nutritional requirements of the Australian red claw crayfishCherax quadricarinatusin order to develop feed formulations that ensure high farming efficiency and economic sustainability in aquaculture. Materials and methods.A comparative – analytical approach was applied in this study. The information base was formed through the analysis of more than 150 scientific publications from both domestic and international sources. Literature searches were conducted in databases such as eLibrary, ScienceDirect, ResearchGate, Google Scholar, Wiley, and others, using keywords in both Russian and English. Results.The analysis revealed thatCherax quadricarinatusis capable of effectively digesting both plant- and animal-based dietary components. Protein was identified as the primary limiting nutrient, with an optimal content for juveniles ranging between 30-33%. As an alternative to fish meal – the most expensive component of aquafeeds – promising protein sources include black soldier fly larvae, yellow mealworms, poultry by-products, and microbial protein DREAMFEED. The species’ specific feeding behavior necessitates high water stability and mechanical strength of feed pellets, as well as adjustment of their shape and size according to crayfish age; prismatic pellets are considered optimal. Experimental studies of both domestic and international feed formulations demonstrated that the use of alternative protein sources and locally available raw materials can reduce feed costs without compromising growth rates or survival. Conclusion.The efficiency ofCherax quadricarinatusaquaculture is largely determined by the quality and nutritional balance of the feed. The biological features of this species, including its versatile digestive system and ability to process a wide range of organic substances, provide a basis for the development of diets using alternative protein sources. Diets that maintain an optimal balance of proteins, lipids, carbohydrates, vitamins, and minerals contribute to enhanced productivity, survival, and profitability of aquaculture farms. The improvement of feed formulations and manufacturing technologies aimed at increasing water stability and adapting pellet size to different developmental stages represents a key direction for the further advancement ofCherax quadricarinatusaquaculture.

Background.At the present stage of urban development in Donbass, the problem of the ecological state of the environment and the assessment of ecosystem sustainability has become particularly acute, aggravated by the impact of new anthropogenic and manmade factors. One of the priority tasks of the region is the selection of species and the scientific substantiation of the list of the main forest-forming species of Donbass. Purpose.The purpose of this study is to evaluate the ecological and biological properties of species of the genusAcer L., growing in the changing climate of Donbass and anthropogenic stress. Materials and methods.Field research and material collection were carried out in the period from 2023 to 2025 along the highways of Donetsk city and park areas. During the study, trees of six species of the genus Acer L. were evaluated. in the conditions of the steppe zone of Donbass:Acer campestre L., Acer negundo L., Acer platanoides L., Acer pseudoplatanus L., Acer saccharinum L., Acer tataricum L. The viability of the trees was assessed using the Alekseev integral scale. To assess the strength and mechanical stability of woody plants growing in an urbanized city, the following parameters were used: bending resistance, maximum permissible load and weight, relative bending resistance. Results.As a result of the conducted research, the ecological and biological properties of six species of the genusAcer L. are described. The viability, morphometric parameters, and age structure of Acer L. plantings have been determined. From the standpoint of biomechanics of living systems, species with higher wood density and fiber elasticity,A. campestreandA. platanoides, demonstrate increased resistance to mechanical damage, which allows them to withstand extreme weather events and maintain their structure in conditions of anthropogenic impact. For plantsA. negundo, from the standpoint of the anatomical features of wood and the physico-mechanical properties of tissues in an urban environment, after 35 years, mechanical stability decreases by ~60%, which affects the accident rate of such trees.A. tataricumretains stable physico-mechanical characteristics both under control conditions and in areas exposed to anthropogenic influences. This fact indicates the potential expediency of its use in landscaping projects. However, given its aggressiveness, selective rather than large-scale use is recommended, for example, for the formation of hedges or alley plantings. Conclusion.The results obtained can be used to develop urban greening strategies, taking into account the sustainability and adaptability of various species of the genusAcer L. This will create more stable and functional urban ecosystems in a changing climate, as well as capable of withstanding anthropogenic factors and providing favorable conditions for human and animal life.

Background.Modern applied biotechnology is focused on the development and implementation of fundamentally new multifunctional feed additives in a complex form. Currently, new approaches to the maintenance of farm animals and aquaculture objects under the influence of environmental factors are being sought, based on the use of biologically active additives. Intensive antibiotic therapy has become one of the reasons for the disruption of normal bacteriocenosis and a decrease in the immunobiological reactivity of animals and fish, the emergence of resistant strains of pathogens, which reduces the therapeutic effect of antibacterial drugs. The use of antibiotics leads to the accumulation of microorganisms with complex antibiotic resistance in the environment, their entry into natural water bodies is almost impossible. One of the promising ways to solve these problems is the use of feed additives with immunomodulatory action. The article examines existing feed additives with biological activity, provides generalized literature data on the use of biological additives in animal husbandry and aquaculture. Purpose.The objective of the present study is to investigate impact of immunomodulatory feed additives on farm animals and fish. Materials and methods.Feeds play a crucial role in the diet of farm animals and fish, as they must contain all the necessary nutrients, vitamins and minerals to ensure healthy growth and development of animals and aquaculture objects. Such preparations as probiotics (including symbiotics and metabiotics), prebiotics, and synbiotics, which are actively used in feed production, meet these requirements. In 1995, Gibson and Robertfroy introduced the concepts that should be classified as prebiotics and found that these components should be: 1) a selective component that promotes the metabolic activity or growth of one or more beneficial bacteria; 2) capable of altering the microbiota towards a healthy state; 3) capable of exerting a systemic or luminal beneficial effect on the host organism; 4) not absorbed and not hydrolyzed in the upper part of the stomach. Results.Current research shows the positive impact of prebiotic use on performance, including improved weight gain, improved feed conversion and reduced disease. Prebiotics promote the growth of beneficial microorganisms such as bifidobacteria and lactobacilli in the intestines of animals. This reduces the concentration of pathogens such as salmonella and coliform bacteria, which reduces the risk of disease and improves the overall health of animals and fish. Research confirms the possibility of reducing the use of antibiotics in feed through the use of prebiotics, which is important in the context of the problem of antibiotic resistance. Prebiotics can be used to improve the environmental sustainability of livestock and aquaculture, as they help to reduce the release of harmful substances into the environment. Conclusion.Numerous scientific studies confirm the beneficial effects of immunomodulatory additives on the health of animals, poultry and aquaculture objects, especially in terms of protection against pathogens, stimulation of the immune response and increased productivity. Prebiotics can be used as an alternative or enhance the effect of probiotics. The use of a combination of these components, demonstrating a synergistic effect, can be even more effective in stimulating the intestinal microbiota and protecting animal health. One promising area of research is the use of wheat grain heap as an immunomodulatory additive, which has high prebiotic properties. In the future, it is necessary to pay attention to studies of the thermal treatment of grain in the production of feed and feed additives. It should be emphasized that the use of feed additives such as probiotics, prebiotics and synbiotics is safe, does not have a negative impact on the natural environment and reduces the demand for antibiotic-based growth promoters. However, the mechanisms of action of probiotic organisms, prebiotics, and their combinations in synbiotics require further research. In the technology of compound feed production, plant raw materials, including wheat, are subjected to the extrusion process in order to increase the nutritional value, during which, during heat treatment, pathogenic microorganisms are killed. Presumably, wheat grain of early ripeness phases may lose its beneficial properties during heat treatment (extrusion). In this regard, it is advisable to conduct research on the effect of grain processing on its prebiotic properties.