The purpose of the research is to highlight the life and creative path of Doctor of Agricultural Sciences, Professor I.I. Klodnytsky, his contribution to the organization of the system of higher professional education and experimental work in Ukraine, the development of the scientific foundations of breeding work. The research methodology is based on the author's use of the methods of historical and scientific analysis, as well as the biographical method. The research source base covers a wide range of published and unpublished works; it is based on archival materials and scientific publications by I.I. Klodnytsky.

The scientific novelty of the publication lies in the substantiation of the scientific contribution of the scientist to the formation of the genetic basis for breeding of farm animals. The scientist made efforts to establish a domestic breeding work as a developer of the first plan of breeding work with Simmental cattle for the breeding farm "Trostyanets" Chernihiv region. The creative heritage of I.I. Klodnytsky, whose scientific works were mainly devoted to the study of patterns of heredity and variability of dairy productivity of cattle, the influence of paratypic and genetic factors on its formation, assessment of breeding value, as well as genetics and reproducing of poultry. It is substantiated the expediency of the assessment of the sires should be carried out on a set of grounds (constitution and exterior, origin, quality of offspring). In the field of poultry farming, the main achievement of the scientist is the development of methods for selection of poultry and its assessment of the productivity of offspring, justification of the feasibility of artificial mutagenesis in chickens by X-ray of sperm.

The scientist prepared the first textbooks on farm animal genetics for the system of higher professional education.

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6. Klodnyckyj, I. I., Bulakh O. K., & Voedylo A. L. (1939). Symmentaly plemsovkhoza «Trostjanec» y selekcyonno-plemennaja rabota s nymy [Simmentals of the breeding farm "Trostyanets" and selection and breeding work with them]. Sovetskaja zootekhnyja [Soviet zootechnics]. 8. 28–34. [in Russian].
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8. Klodnycjkyj, I. (1926). Zminlyvistj i koreljacija tila v velykoji roghatoji khudoby [Variability and correlation of the body in cattle]. Zapysky Kyjivsjkogho veterynarno-zootekhnichnogho instytutu [Notes of the Kyiv Veterinary and Zootechnical Institute]. Kyiv. 34–42. [in Ukrainian].
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