Study of the effect of betulin-containing feed additive on lysozyme and bactericidal activity of blood serum of calves and dairy cows

A scientifically of the effect of betulin-containing feed additive on the lysozyme and bactericidal activity of the blood serum of calves and dairy cows in the conditions of a livestock complex was carried out. It was shown that after 14 days of the experiment, the lysozyme content in five-month-old calves of the experimental group was higher than in the control by 18.5% (p ≤ 0.01), in ten-month-old calves of the experimental group it was higher than the control by 23% (p ≤ 0.01), and in cows of the experimental group it exceeded the lysozyme content of the blood serum of cows of the control group by 35% (p ≤ 0.05). It was found that after 14 days of the experiment, the content of BASK in five-month-old calves of the experimental group exceeded the value of the control group by 22.5% (p ≤ 0.05), in ten-month-old calves of the experimental group it exceeded the data of the control group by 14.7% (p ≤ 0.01) and in cows of the experimental group by 36.75% (p ≤ 0.05) BASK was higher than in cows of the control group. Thus, the data obtained demonstrate the activation of nonspecific resistance factors in all studied age groups of animals after giving a feed additive containing betulin, and confirm the prospects of using a natural feed additive to correct the immune status of cattle.