The use of a carbohydrate prebiotic component in breeding bulls feeding

The aim of the study is to evaluate the effect of the carbohydrate prebiotic component on the metabolic processes of breeding bulls. The scientific and economic experiment was conducted on Holstein breeding bulls at KrasnoyarskAgroplem JSC, the Yemelyanovo District, the Krasnoyarsk Region, from July to No-vember 2024. Two groups of bulls, 20 heads each, were formed based on the principle of analogous pairs, taking into account breed, age, and live weight. At the beginning of the experiment, the animals were in the same feeding and housing conditions (seven days), then the feed additive UK 2-02 Zhivoj belok was ad-ded to the main diet of the breeding bulls of the experimental group, starting with 5.0 % (50 g/head per day, at a rate of 1 kg/head per day) of the recommended rate. The portion of the additive was gradually increased in search of the optimal dose and reduction of stress that occurs when changing feed. The diet was balanced for 700 kg of live weight with average work of the breeding bull (two to three mountings per day with the following day of rest). Animal care corresponded to the routine adopted at the enterprise. Bio-chemical blood analysis indicates normalization of metabolic processes in the experimental animals after the use of the carbohydrate prebiotic component UK 2-02 Zhivoj belok. The ALT indicator decreased by 21.21 % from the upper reference value (37.03 U/l) and returned to normal. The alkaline phosphatase le-vel also turned out to be lower by 2.05 % (318.33 U/l) compared to the same indicator at the beginning of the studies. As for creatine kinase (CPK), the value of this indicator dropped from the upper mark of 275.67 U/l and amounted to 223.47 U/l, which is 2.0 % lower than the norm (228.0 U/l) and 18.3 % higher compared to the control group. The obtained result can be explained by the increase in muscle activity of the breeding bulls, since they produced 40.5 % more sperm compared to the beginning of the experiment and 37.1 % more sperm than the control group. The excess of urea in the blood of animals at the begin-ning of the experiment was 35.0 % of the norm, but by the end of the test period this indicator dropped to 3.48 mmol/L, which is 3.34 % lower than the upper standard value, while in the control group the excess was 6.12 % (3.82 mmol/L) compared to the reference value. We assume that the breeding bulls of the ex-perimental group increased the absorption of protein from the consumed feed and decreased the disrup-tion of protein and fat metabolism. The introduction of UK 2-02 Zhivoj belok in the diet of breeding bulls in the amount of 400 g per head per day had a positive effect on the restoration of energy expenditure of the animal's body and, in general, on the normalization of metabolic processes.