Effectiveness of the use biologically active substances in the rations of young cattle

The input of probiotic additives RuminPro and Actisaf in the diet of young cattle in the amount of 3 g/head during the entire milk period of rearing showed that the feed additive RuminPro allows to increase the absolute gain in live weight of calves by 5.76 %, the additive Actisaf by 1.71 % with an average daily gain of 883.59 g (р ≤ 0.001) and 849.75 g (р ≤ 0.001) in comparison with the absolute gain in live weight of the control group, where it was 150.38 kg. In general, during the observation period the relative gain in live weight of calves in the 1st experimental group receiving RuminPro exceeded the control group by 1.87 abs.% (р ≤ 0.001), and the relative gain in calves in the 2nd experimental group using the probiotic Actisaf did not diff er from the relative gain in the control group and were at the level of 135.68 %. It was found by analyzing the results of blood tests in calves using the probiotics RuminPro and Actisaf that the use of RuminPro had a more favorable eff ect on the total protein indicators at 2 months of age 64.66 g/l, while in the 2nd experimental group the indicator was 60.78 g/l. At the age of 6 months, a similar pattern was noted for the superiority in the total protein content in the experimental groups by 5.6–7.9 %, with a reliable diff erence in the 2nd experimental group (р ≤ 0.05). These results showed that RuminPro had a more favorable eff ect on the protein-synthesizing function of the liver in this group of calves. Positive changes in the body of calves when using feed additives made it possible to reduce feed costs per unit of live weight gain. Thus, when using the probiotic RuminPro during the period of calves rearing, costs decreased by 5.2 %, and the probiotic Actisaf by 1.4 %.