Scientific Horizons

7-13

Authors: Pavlo Zabrodskyi, Bohdan Sheludchenko, Savelіі Kukharets

Cut-off tools equipped with carbide inserts are commonly used in turning operations. Due to the very heavy conditions in which such blades work, they fail, as a rule, not as a result of their operation, but due to the breakage of carbide inserts. This study investigates the causes of such failures and methods to prevent such phenomena. A thorough analysis of the current state and research methods of stress state in cutting tools, including turning cutters, was carried out. Methods of stress reduction in carbide inserts were also analysed. This paper focuses on the study of the stress state in cut-off tools with brazed carbide inserts. The stress state in the carbide inserts and the influence of different fixation methods of carbide insert to the holder were considered. The main approach to stress studies was the photoelasticity method, which allows quickly and clearly obtaining and evaluating the results. Models of carbide inserts were made of optically sensitive material. It as a part of a complex model of a cut-off tool with a carbide insert with three different methods of fixation were loaded with a force by means of a specially designed stand simulating the cutting force. The study was carried out on a PPU-7 polarisation-projection unit. Isochromatic and isocline patterns were obtained. The estimation of the principal stresses was performed by the difference of shearing stresses for three cross sections of the insert: at the surface, in the middle and at the base. It was found that the best result is given by the method in which the insert on the side far from the cutting edge has a bevel made at an angle of 10°

22-28

Authors: Viktor Doylidov

Ethologists have identified many aspects of animal behaviour, and their research experience can be used in agricultural production for the selection of animals with necessary behavioural qualities. The purpose of the study was to find labour saving and effective methods for the selection of young pigs for herd replacement, including identification of their behavioural characteristics in the context of industrial pork production. The method for the selection of young animals based on the viability index of newborn piglets was compared with other method, which takes into account the independent attachment of piglets to the front three pairs of sow teats. It was found that the probability of independent attachment of a piglet to anterior teats has a positive and high correlation with its viability index, with a correlation coefficient of 0.95. Piglets that occupied the front three pairs of teats during the suckling period significantly (P≤0.001) exceeded the rest in weight at the 21st and at the 60th days by 22.7% and 5.4%, respectively. When assessing the behavioural reactions of piglets weaned from sows in an artificially created stress conditions, groups of piglets resistant and not resistant to psychological (emotional) stress were selected for subsequent observation. Moreover, it was found that among the sows obtained from stress-resistant piglets, the superiority in fertility during the first insemination and the total proportion of farrowing was 11.1 p.p., in terms of multiple fertility – 2.6 piglets (P≤0.05) or 33.3%, and in terms of the share of those transferred to the main herd – 27.8 p.p. in comparison with the group of unstable ones. Based on the obtained results, the use of an ethological method for selecting piglets for herd replacement was substantiated, taking into account the independent attachment to anterior teats and an express method for selecting piglets based on their resistance to psychological stress

36-44

Authors: Valeriy Mykytyuk

An important condition for the provision of the country's food security is the production of sufficient quantities of food ensuring its proper quality. The current state of development of the livestock industry, as the main supplier of the population with meat, milk and other products both in Ukraine and at the regional level does not meet its potential capabilities. The purpose of the study was to investigate the trends and patterns of the current state of the livestock industry at the regional level and to find the main ways of its development. The study used general scientific and economic-statistical methods, namely: series of dynamics, analysis and synthesis, comparison. Analysis of the current trends in the livestock industry at the regional level as well as some of its indicators in general for Ukraine was carried out. Changes and dynamics of the average annual available number of livestock and poultry by groups of animals are revealed. It was found that the positive changes in the number of animals led to an increase in meat production, including lamb and goat, and poultry. However, this did not increase the production of beef, pork, milk and honey. The structure of meat production does not fully correspond to the natural and economic area of the animal husbandry. The influence of changes in the dynamics of the level of productivity of farm animals on the gross output of products, especially in the branches of pig breeding, sheep breeding, beekeeping, is estimated. According to the results of the research, the level of production of the main types of livestock products per capita has increased, but does not yet fully meet the physiological norms of consumption of these products. Feed evaluation in animal husbandry allowed measuring the efficiency of their use in terms of nutrients per 1 conventional head and unit of production by its types. An assessment of the economic efficiency of the industry is carried out according to the main indicators that summarise it. In the structure of production costs, the largest part is occupied by direct material costs. It was found that only the production of milk and chicken eggs was profitable. The study suggests the main approaches to the development of the livestock industry in the future

54-60

Authors: Viktor Mazur, Ihor Didur, Oleksandr Tkachuk, Hanna Pantsyreva, Vitaliy Ovcharuk

A prerequisite for increasing the area of sparsely distributed leguminous crops lies in the analysis of their cultivars according to agroecological indicators. Therefore, the purpose was to develop the State Register of plant cultivars suitable for distribution in Ukraine for 2021 and Official descriptions of plant cultivars and indicators of economic suitability, highlighted in the information and reference system “Sort” (cultivar) regarding the assessment of agroecological resistance of cultivars of sparsely distributed legumes. The highest potential seed yield, according to the State Register of plant cultivars of Ukraine, is attributed to horse bean cultivars Tiffani and Fanfare, lentil cultivars YeS Maksymum, Blondi and SNIM 18, chickpea cultivars Goksu, Aras, Zehavit, YeS Alunt and a cultivar of grass pea Ivolha. The highest resistance to diseases is attributed to the cultivars of horse beans Birgit, Apollo, and Stella, cultivars of lentils Blondi, Khryzolit, SNIM 18, Harri, Linza, cultivars of chickpeas Odysei, Zodiak, Rodin, Oven, Stepovyi velet, and all cultivars of grass pea. The most resistant to pests are horse beans Sirius and Fanfare, lentil cultivars Harri, Blondi, Khryzolit, SNIM 18, cultivars of chickpea Dostatok, Zodiak, Lara, Yaryna, YeS Alunt, Rodin, Stepovyi velet, Kozeroh and Odysei. The most drought-resistant is the cultivar of grass pea Ivolha, as well as most cultivars of horse beans, except Sirius and Fanfare, lentil cultivars, except YeS Maksymum, Antonina, and Harri, chickpeas, except Zehavit and Budzhak cultivars. Analysis of agroecological resistance of cultivars of sparsely distributed leguminous plants and their potential seed yield showed that to a large extent, high productivity is ensured by resistance to adverse agroecological factors: the influence of diseases, pests, and drought. The practical value of the study is to recommend the production of cultivars of sparsely distributed legumes with the highest indicators of resistance to diseases, pests, and drought with the highest potential yield

68-76

Authors: Olena Andreieva, Ivan Martynchuk, Olena Zhytova, Anatoliy Vyshnevskyi, Anastasiia Zymaroieva

Foliage damage by leaf-eating insects during mass reproduction causes deterioration of the sanitary state of forest and a decrease in its increment. Timely detection of pest foci allows reducing the cost of their elimination and preventing negative consequences for stands. The purpose of this study was to identify the species composition of leaf-eating insects on the territory of State Enterprise Zhytomyrske Forestry and the subcompartments with the greatest threat of foci development of the dominant species – Tortrix viridana, taking into account forest site conditions and stand structure. During the feeding period, the species composition of leaf-eating insects was identified, and after the end of oviposition, the density of Tortrix viridana egg masses was assessed on tree branches selected in subcompartments with different forest site conditions, age, the relative crop density, and proportion of oak in the stand composition. The database of forest inventory (Ukrderzhlisproekt) and the score assessment of the preferences of stands for foci development were used. Eleven species of leaf-eating insects from order Lepidoptera were identified, including 9 species from the family Tortricidae, of which Tortrix viridana dominated. The highest egg mass density of this pest was assessed in fresh dubrava conditions (D2), in pure oak plantations aged 40-80 years with a low relative crop density. The average score of stand preference for Tortrix viridana was assessed by forest site conditions (2.93 and 2.88 for seed plantations and coppice forest, respectively), age (3.65), the relative density of stocking (2.6), and oak participation (3.3) in the State Enterprise Zhytomyrske Forestry. The list of subcompartments with a very high and high threat of an outbreak of Tortrix viridana has been established. A survey in these subcompartments would allow timely detection of pest population increase and prevent its development

85-92

Authors: Vasyl Martynenko

The paper deals with the ecological and fire situation in the forest ecosystem of the “Drevlyansky” nature reserve. The relevance of this study is that every year Ukraine's forests suffer from fires that destroy significant areas, and forests with radiation pollution suffer from fires the most. The purpose of the study was to investigate the impact of radiation pollution on the fire situation in the forest ecosystem of the reserve. The main task was to distribute the area of the reserve according to the level of radiation pollution and fire hazard classes with and without taking into account radiation pollution. To achieve the results, the area of the forest ecosystem of the Reserve was distributed according to the levels of radiation pollution. The average fire hazard class between 2008 and 2018 ranged from 2.02 to 2.06, which in turn improves the fire situation. However, since the territory of the reserve has been exposed to radiation pollution, the distribution of areas by fire hazard classes has undergone changes between the years of forest management. Thus, the fire situation, taking into account radiation pollution, has deteriorated compared to the area that was not exposed to radiation pollution, and between 2008 and 2018 it improved and amounts to 1.16 and 1.17, respectively. Consequently, the distribution of area by fire hazard classes depends not only on the level of radiation pollution, but also on the taxational specifications (land category, and in plantations it depends on the type of forest vegetation conditions, age, and tree species). The results of the fire that occurred on the territory of the reserve in the spring of 2020 are shown, along with a map of the fire danger of the forest fund of the “Drevlyansky” nature reserve in 2018. The prospect of further research is to re-conduct a study of the level of radiation pollution and to carry out actual measurements every 10 years, without using calculation methods. This will provide a more reliable distribution of forest fund areas by fire hazard classes and affect the planning of strategic tasks to prevent fires in the reserve