Koshevoy V. Reduction of reproductive capacity of boar-sires under oxidative stress and methods of its correction

Dissertation is devoted to the scientific and experimental substantiation of pathogenetic mechanisms of reducing the reproductive capacity in boars and the development of a method of its correction of redox-active nanoparticles. Based on biochemical and analytical and statistical studies, the presence of hormone and metabolic changes in the decrease in the quality of sperm of males, the effect of gadolinium orthovanadate nanoparticles hydrosol on the germinative-endocrine function of testes, hormone balance, prooxidant/antioxidant balance and comparative and economic efficiency of the proposed method of correction of boar infertility is evaluated. Qualification scientific work is part of the initiative topic with the state registration of the Department of Veterinary Reproductology of Kharkiv State Zooveterinary Academy (from 01.09.2021 – Department of Veterinary Surgery and Reproductology of State Biotechnological University) “Development and implementation of innovative methods and solutions using information and technical devices in veterinary reproductive medicine”(term of execution 2015-2025, state registration number 0114U005415). Experimental studies were carried out in four consecutive series of experiments: in the first series, the state of the prooxidant-antioxidant system of boars with different indicators of sperm quality (normal and reduced) was determined, in the second – the influence of nanoparticles of gadolinium orthovanadate on the reproductive function of laboratory animals (rabbits) was determined under tert-butylhydroperoxide-induced oxidative stress, which made it possible to substantiate the development of the newest method of infertility correction, which was tested on boars with reduced reproductive capacity in the third series of experiments, and in the fourth – the effectiveness of the use of nanoparticles was compared with the vitamin-hormonal preparation “Karafand” and the economic feasibility of the developed correction method was determined. The scientific novelty of the obtained results is to substantiate the effectiveness of the use of nanoparticles of rare-earth elements, in particular, gadolinium orthovanadate, with pronounced antioxidant properties with reducing the reproductive capacity of boars on the basis of complex studies of its biochemical mechanisms and obtaining new scientific data on the balance of peroxidation processes and antioxidant protection of their body. There is a significant increase in the number of oxidative stress markers in animals with a decrease in reproductive capacity, in particular, the first determined content of stable metabolites of the Nitrogen oxide cycle. New scientific data on the activity of the antioxidant defence system in boars with low sperm quality. For the first time, the content of testosterone-estradiolbinding globulin in the serum of boars, which investigated the androgen saturation of the boar body, in particular, the free androgen index was determined. For the first time, the efficiency of use of gadolinium orthovanadate nanoparticles is shown to correct the reproductive capacity of boars. Their positive effect on the intensity of the processes of the lipid peroxidation and the antioxidant status of the serum of boars. Improve the dynamics of sperm quality and hormonal background of the fruit. A comparative evaluation of the effectiveness of the use of nanoparticles with a vitamin-hormonal drug was carried out and the economic efficiency of the developed method of correction was determined. The practical significance of the results is confirmed by positive changes in the ejaculate and the normalization of hormonal background in boars for the use of gadolinium orthovanadate nanoparticles for reducing their reproductive capacity. The results of the research were included in the methodological recommendations “Method of correction of reproductive capacity of boars with gadolinium orthovanadate nanoparticles” (approved by the Methodological Commission of the Faculty of Veterinary Medicine of the State Biotechnological University of the Ministry of Education and Science of June 21, 2022), which was tested in the farms of Dnipropetrovsk region and recommended for use. The main results of the dissertation were introduced into the educational process and research work at the departments of higher education institutions of Ukraine: obstetrics, gynecology and biotechnology of reproduction of animals of the National University of Life and Environmental Science of Ukraine; obstetrics and surgery of Sumy National Agrarian University; surgery and obstetrics of farm animals of Dnipro State Agrarian and Economic University; veterinary surgery and reproductology of the State Biotechnology University, as well as in the research work of the department of nanostructured materials named after Yu.V. Malyukin of Institute of Scintillation Materials of NAS of Ukraine.