Abstract. In dairy cattle breeding, feeding rations directly affect the general condition of animals, indicators of productive and reproductive capacity, as well as the level of nutritional and biological value of the raw materials obtained. The most important task of modern domestic cattle breeding is the development of balanced diets enriched with various feed additives, in particular, prebiotic orientation. The introduction of various prebiotics into the diet of first-calf heifers of the Red Steppe breed has an important practical significance. The aim of the work is to study the effect of new prebiotic feed additives “LaktuVet” and “LaktuSuper” on the productive ability of first-calf heifers, as well as on the qualitative and quantitative composition of the milk obtained. Methods. An experimental study was carried out at the dairy complex “Breeding farm – collective farm named after Lenin” of Surovikinsky district of the Volgograd region. During the experiment, it was planned to distinguish three groups of cows – the control and two experimental ones. The control group was fed with a standard diet approved at the complex. The experimental group I was fed with a standard diet with the introduction of the feed additive “LaktuVet” at a dose of 0.5 % by weight of the feed. For feeding the II experimental group, a standard diet was used with the introduction of the feed additive “LaktuSuper” 0.5 % of the mass of the consumed compound feed. The scientific novelty lies in obtaining new knowledge about the effect of new prebiotic feed additives on the productivity of cows, as well as changes in the physicochemical composition of the resulting milk. Results. It was found that the use of new prebiotic feed additives in the diets of first-calf cows contributed to an increase in the amount of milk received in animals of the I experimental group by 5.59 %, in analogues of the II group – by 8.07 % compared with the control group. The introduction of feed additives into the diet of the studied cows had a positive effect on the quality of the milk produced and its amino acid composition.
