GROWTH AND DEVELOPMENT INDICATORS OF CALVES WHEN USING IMMUNOMODULATORS

The aim of research is to study the effectiveness of the impact of immunomodulatory drugs Azoksivet and Roncoleukin on productive indicators characterizing the rate of growth and development of calves. Experimental studies were carried out in the Kemerovo Region in 2019–2020. Experimental groups were formed from newborn heifers of the Black-and-White breed according to the principle of pair-analogues. For the period of the study, the conditions for feeding and keeping calves were similar, with the exception of the studied factors. To study the effect of drugs on the rate of growth and development, control weighing and measurements of calves were carried out at birth and at the end of the experiment at 90 days of age. The calves of the second experimental group significantly outperformed their counterparts from the control group: in terms of absolute weight gain, by 7.3 kg (p < 0.05); relative gain – by 22.1 % (p < 0.05) and average daily gain in live weight – by 81.1 g (p < 0.05). Calves from the first experimental group significantly exceeded their peers from the control group: in terms of height in the sacrum – by 1.5 cm (p < 0.05); chest width – by 0.8 (p < 0.05); chest girth behind the shoulder blades – by 1.8 (p < 0.05); width in makloks – by 1.0 (p < 0.05) and metacarpus girth – by 0.4 cm (p < 0.01). Calves from the second experimental group were significantly superior to their counterparts from the control group: in height at the withers – by 1.6 cm (p < 0.05); height in the sacrum – by 1.4 (p < 0.05); across the width of the chest – by 1.0 (p < 0.05); oblique body length – by 2.1 (p < 0.01); chest girth behind the shoulder blades – by 2.2 (p < 0.05); width in makloks – by 1.3 (p < 0.01) and metacarpus girth – by 0.5 cm (p < 0.01). The survival rate of the experimental livestock during the period of the experiment was 80 % in the control group; in the first experimental group – 100 %; in the second experimental group – 100 %.