Abstract
Relevance. Holstein dairy cattle are bred in the Sverdlovsk region, its improvement is carried out by selecting and selecting the best for further breeding. In order for them to display their genetic potential of productivity, it is necessary to ensure a balanced diet. The aim of the work was to assess the diversity of dairy characteristics in Holstein cows when using the “VivAktiv” feed additive. Methods. To conduct the study, 4 groups of calved heifers with 10 heads each were formed in a typical breeding plant for the region: a control group and three experimental ones based on the principle of pairs of analogues. The dairy productivity of cows was evaluated for the first lactation and for the calendar year by control milking once a month. The fat and protein content in milk was assessed in an average milk sample once a month from each cow. The coefficient of variability (variation) was calculated according to the generally accepted formula. Results. As a result of the conducted research, it was found that the use of the “VivAktiv” feed additive did not significantly affect the productivity of cows. The milk yield for lactation by group was 10582.3 ± 187.35, 10640.8 ± 163.89, 10293.9 ± 176.45 and 10080.1 ± 178.13 kg, respectively, the difference was unreliable and insignificant. Considering the changes in the coefficient of variation between the groups, we can note a lower variability of the trait in cows of the 2nd experimental group. The animals of the control group came in second place. The largest variety of the trait turned out to be in the 3rd experimental group. Thus, the variability of the trait is influenced by the period (month) of lactation, to some extent the duration of lactation, as well as the use of the feed additive “VivAktiv”, which had a stabilizing effect on cow yield when used at a dose of 20 g/head/day.