The article is devoted to the development and synthesis of a new drug for use in animal husbandry and veterinary medicine as an immunostimulatory and adaptogenic agent. The basis of the new drug is a combination of magnesium, phosphorus, and casein of cow's milk. Given the important scientific and practical importance for veterinary medicine of innovative drugs that would have pronounced immunostimulatory and adaptogenic properties, the aim of our research is to develop a method of obtaining a new drug with an original composition and further studies of its effectiveness and safety. Modern materials and methods were used to achieve this goal. In particular, mass spectrometry was used on a Waters H-class UPLC liquid high-pressure liquid chromatography spectrometer with a Waters TQ-S micro three-quadrupole detector; atomic emission spectrometer with inductively coupled plasma Analytik-Jena Plasma Quant PQ 9000 Elite; liquid chromatographer with a three-quadrupole mass detector and with analytical column – Waters ACQUITY UPLC BEH C18 1.7μm 2.1x50mm. The result of the work was the development of a method of modification of the casein molecule, which was carried out in several stages: the first stage was the direct phosphorylation of the casein molecule; the second stage of the synthesis was the chelation of magnesium with casein. Based on the results of this work, the following conclusions were formed: 1) the synthesis of a new drug is carried out in two stages: the first – modification of casein by direct phosphorylation and the second stage – chelation of magnesium with casein; 2) it was found that the efficiency of phosphorylation directly correlates with the number of treatment cycles of the reaction mixture and is optimal for three treatment cycles

The studies, which may reveal some elements of regulation between the metabolic processes of proteins (at the level of translation and changes in the amino acid spectrum) as well as catabolism and anabolism of carbohydrates under conditions of pathological deviations of the functioning of the animal organism, are promising, and the search for protective substances of a different nature is necessary. The aim is to study and analyze a bio protectors’ effect on the composition of some amino acids under alcohol-induced oxidative stress. During the experimental period, changes in the body weight of rats confirm the depressant effect of alcohol on the dynamics of weight gain of animals during their growth and development, and the positive protective effect of betaine and additives (protein+minerals). The increased activity of alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase in the blood serum of rats in experimental groups of animals with the absence of protectors’ substances in the diet indicates a deviation in the functional capacity of the liver. The determined indices of the content of creatinine and urea were increased significantly that points out on possible pathological deviation of the kidney. Under alcohol substances, changes of such biochemical indexes value as lactate dehydrogenase, superoxide dismutase, and catalase, and the content of malonic dialdehyde indicate oxidative stress. In the case of bio protectors’ presence, values of biochemical parameters become to ones in the animals of control groups. It was observed, that betaine has a higher potential for the correction of the above pathological abnormalities than protein-containing additives with minerals in the form of chelate, but the last is perspective for further study and their use as a raw material for the development of more complex bio protectors