Making optimal conditions for feeding and housing of young animals ensures the correct and timely development of internal organs, including reproductive function, which has a positive impact on the realization of the high genetic potential of animals in adulthood. This can only be achieved by using balancing additives such as premixes developed on the basis of an actual analysis of feeding conditions. The purpose of this work was to study the feasibility of using premixes developed taking into account feeding characteristics (targeted) in the rations of replacement heifers up to 12 months of age. The experiment was carried out at the Staraya Chigla livestock complex of EkoNivaAgro-Severnoye LLC, geographically located in the Anninsky district of the Voronezh region from 2020 to 2023. The heifers were selected by using the analogue pair method and distributed into groups of 12 heads in each (control and experimental groups). It was established as a result of the studies that the use of a targeted premix contributed to the intensity of growth of young animals, which was confi rmed by an increase in the live weight of heifers by the end of the experiment by 5,04 %, an average daily gain by 5,74 %, and a relative gain by 1,91 %. Analysis of the reproductive function of heifers showed that the age of fi rst heat occurred 5,5 days earlier in animals of the experimental group, and the age of fi rst eff ective insemination was 18,09 days earlier. Fertility from the fi rst insemination was higher in heifers that were fed the targeted premix by 8,34 %. The insemination index was also better in the experimental group. Thus, the research has proven the feasibility of developing and using targeted premixes.