The physiological state of animals is to a certain extent characterized by hematological indicators, since blood occupies a special place in the body. By transferring nutrients and biologically active substances, the blood performs the general regulation of vital functions of the body. The use of Vitartil as a feed additive in the diets of animals leads to an increase in glycolytic processes and a decrease in the body’s need for oxygen delivery, which contributes to the growth of the animal body. The purpose of the research was to study the changes in blood parameters taking into account the age of Hereford steers against the background of the use of Vitartil feed additive to the main diet and its effect on the productive traits of animals. In order to carry out the experiment two groups of steers-analogs of Hereford breed have been formed at the age of 6 months per 10 heads in each. The difference between the groups was that the steers of the experimental group have been received the feed additive Vitartil in addition to the main diet. The greater yield of the meat part was in the steers of the experimental group in comparison with the herdmates of the control group. This indicator in the experimental group was 78,9 %, while in the control group it was lower by 1,6 %. The animals of the experimental group were superior to their herdmates in terms of meat weight by 1,4 kg or by 8,8 %. The relative number of bones was lower in the experimental group and amounted to 18,4 %, and in the control group 19,2 %. The meat content index was high in the steer have been received the biologically active additive Vitartil and was 4,3, and in the control group 4,0. It has been found that the use of Vitartil feed additive to the main diet of Hereford steers increases the blood content of hemoglobin and glucose, which has a certain effect on the morphological and chemical composition of meat, as well as increases its energy value.