In modern conditions, the fullest possible realization and preservation of productive longevity of highly productive animals is of particular importance. The development and application of specialized feed products aimed at optimizing metabolic processes and increasing the efficiency of nutrient absorption is an urgent task of animal science. A promising direction is the use of prebiotics, substances that selectively stimulate the growth and activity of beneficial microflora of the gastrointestinal tract. The aim of the research was to study the effect of carbohydrate prebiotic feed UK 2-02 "Live protein" on body weight gain and changes in the physiological development of young cattle. To conduct the experiment, four groups of repair young cattle were formed: two groups of heifers and two groups of steers, 20 heads in each group. The studies were conducted on calves from birth to 6 months of age. As a result, it was found that when a carbohydrate component is introduced into the diet in the amount of 400 g per day, an increase in body weight and average daily gains is observed. During the 6 months of the experiment, the calves and bulls of the experimental groups outperformed the young from the control groups by 203 and 203 g or 42.6 and 31.3% in average daily weight gain, and by 35.2 and 37.2 kg or 40.9 and 30.5% in absolute weight gain. The determination of the growth coefficients of calves confirms the advantage of the weight characteristics of the young animals of the experimental groups. The difference between heifers was 7.3%, and bulls – 8.6%. The young of the experimental groups surpassed their peers in latitudinal measurements, and, consequently, in such indices of physique as: pelvic-thoracic, thoracic, bulge and bony, but inferior in the index of high-legged and elongation. It is recommended that agricultural producers, in order to maintain the physiological needs of the body of repair young cattle, use the studied feed additive in the diets of calves of the dairy period in accordance with the feeding scheme.

Lefler Tamara F., Konev Pyotr P.

1. Afanasyeva A. I., Ogui V. G., Galdak S. A. The influence of the structure of the feeding diet on the morphobiochemical parameters of blood and the level of milk productivity of cows of the red steppe breed. Vestnik Altaiskogo gosudarstvennogo agrarnogo universiteta, 2007;9(35):36–40. EDN IRGOPJ (in Russ.).
2. Buryakov N., Kosolapov A. Liquid polysaccharides in feeding highly productive cows. Rossiiskii veterinarnyi zhurnal, 2013;3:34–36. EDN QZSLRH (in Russ.).
3. Mikolaychik I. N., Morozova L. A., Matasov A. A. Modern aspects of raising young cattle. Kormlenie sel'skokhozyaistvennykh zhivotnykh i kormoproizvodstvo, 2014;5:17–25. EDN SBZYTH (in Russ.).
4. Plyashchenko S. I., Sidorov V. T. Natural resistance of the animal organism, Leningrad, Kolos, 1979, 184 p. (in Russ.).
5. Shabunin S. V., Vostroilova G. A., Belyaev V. I., Alyokhin Yu. N., Sashnina L. Yu., Kabitsky S. N. [et al.] Pharmaco-toxicological assessment and efficacy of tilokolin in colibacteriosis and salmonellosis of calves. Veterinariya, 2010;1:48–52. EDN KZKPDB (in Russ.).
6. Lefler T. F., Konev P. P. The use of a carbohydrate prebiotic component in feeding breeding bulls. Vestnik Krasnoyarskogo gosudarstvennogo agrarnogo universiteta, 2025;6(219):118–127. doi: 10.36718/1819-4036-2025-6-118-127. EDN FFPNKU (in Russ.).