Abstract
Relevance . The breeding of Holstein cattle has revealed problems: reduced reproductive function and shorter productive longevity, often associated with metabolic disorders due to poor diet balance and high productivity. Studying the possibility of long-term productive use of Holstein cows in the region is relevant for improving dairy farming efficiency. The aim was to evaluate the variability of dairy characteristics of cows depending on lactation duration. Methods. The study object was cows that completed lactation, grouped by lactation number. Data from the IAC “SELEX-Dairy Cattle” database and own research were used. Herd structure was studied, average milk yield per lactation was established. Productivity was monitored via control milkings. The coefficient of variation was calculated. Results . The main part of the herd (44.8%) consists of 1st and 2nd lactation cows. Productivity stabilizes from the 3rd to the 6th lactation. The difference between minimum and maximum milk yield exceeds 200%. The coefficient of variation for milk yield (>10%) indicates herd heterogeneity, especially among 1st and 8th lactation cows, due to the mass introduction of replacement heifers without selection. Fat and protein content indicators are stable, their coefficients of variation are within normal limits. Holstein cows can be effectively used up to the 6th–7th lactation. To improve herd uniformity, it is necessary to optimize the selection of replacement young stock.