Currently, in modern cattle breeding special importance is attached to improving the methods of using the world’s genetic resources and increasing the potential of domestic breeds. This is due to the wide spread of crossbreds with diff erent portions of blood and the lack of ways to determine the optimal genotype for further breeding. So the question of the relationship between the genotype and the productive traits of animals is always relevant. The purpose of the research was to study the growth and development of heifers of Black-and-White breed of diff erent origin under the conditions of the natural and climatic zone of the Central Caucasus in the Republic of North Ossetia-Alania. In order to carry out the experiment, 3 groups of newborn calves were formed. The 1st control group included purebred heifers of Black-and-White breed, the 2nd experimental group included heifers of Black-and-White breed with a blood ratio of 1/2 of Holstein breed, and the 3rd experimental group included heifers of Black-and-White breed with a blood ratio of 3/4 of Holstein breed. Experimental animals were fed taking into account the planned gains in live weight. The features of growth and development were studied by individual weighing and taking measurements at diff erent age periods. On the basis of weighing the live weight gains were calculated, and according to the measurements the body conformation indices were calculated. Studies have shown that the superiority of heifers of the 3rd experimental group over herdmates of the 1st control group in the fi rst months of life was 6,2 %, and animals of the 2nd experimental group were 2,7 % better than purebred analogues in this indicator. In the future, this diff erence increased and by the age of 18 months the diff erences between the groups were 7,4 and 9,6 %, respectively. In general, it has been established that the use of Holstein breed gene pool contributes to the increase in the growth and development of young animals. Heifers with 3/4 blood portion of Holstein breed were distinguished by the best live weight gains and body conformation indices.