Object - the metabolic processes in the organism of lactating ewes, their milk yield, chemical composition of milk and its biological value. Purpose - to determine the features of metabolic processes in the organism of Ukrainian Carpathian mountain lactating ewes and Prekos ewes under the action of various levels of mineral elements and fat supplements in the filtroperlit complex in their diet and the influence of these factors on the milk yield, chemical composition and biological value of milk. Methods: Biochemical (electrophoretic, chromatographic, spectrophotometric, radiobiology), zootechnical, mathematics and statistics. Novelty: New data about the influence of addition to the diet of Ukrainian Carpathian mountain lactating ewes the I, I and S and to the diet of Precos ewes S, I, Zn, Co, Cu and fat supplements in the filtroperlit complex on the metabolic processes in the blood of ewes, their milk yield, chemical composition and biological value of milk. Results: It was established that addition Iodine (1 mg/head/day), Iodine and Sulphur (1 mg/head/day and 5g/head/day) to the basic diet of lactating ewes of Mountain Carpathian breed and S, I, Cu, Zn, Co (20 % more than norm) and fat additives in the filtroperlit complex (50 g/head/day) in the ration of Precos ewes improves metabolism in the ewe's organism, their milk yield, chemical composition and biological value of ewes milk. It has been found that concerning factors contribute to the intensity of protein, lipid and mineral metabolism, activities of AST and ALT, alkaline phosphatase, increase of thyroid hormones, vitamins A and E. The using of these supplements accompanied by increasing the average daily live weight of Mountain Carpathian lambs (on 9,2 and 11,1% respectively) and Prekos lambs (7,6 and 10,2 % respectively), due to improved ewes milking. It has been established qualitative changes in protein and lipid composition of ewe's milk by increasing of substitute and essential amino acids content, phospholipids, mono-and polyunsaturated fatty acids, minerals and vitamins A and E. provide improved biological value of ewe's milk. On the basis of these data the expediency of increasing of I, S, Cu, Zn, Co level (20 % more than norm) in the diet of lactating ewes in winter-stall period and balancing their diet for fat content has been substantiated.
