Irynei Ratych is a doctor of agricultural sciences, associate member of NAAS. The main attention was paid to the study of artificial sources of ultraviolet radiation radiation impact on protein metabolism processes in skin and blood of young cattle. One of the stages of research work dealt with studies of metabolism processes and fertility in birds in connection with protein, amino acidic and mineral nutrition of different age, breed and fertility groups of birds. When researching metabolism of mineral sulfur in bird organism, he for the first time conducted a complex study of biochemical mechanisms of exogenous suplhate impact on bird organism with regard for the amount of protein, sulfur-content amino acids and total sulfur in diet by methods of radiology, biochemistry, physiology and nutrition. Theoretical foundations and practical recommendations have been developed on improving efficiency of sodium sulphate use in feed of birds of different age, type and productivity direction.