THE INFLUENCE OF VARIOUS KEEPING SYSTEMS ON THE MORPHOLOGICAL BLOOD COMPOSITION OF BULLS DURING THEIR INTENSIVE RAISING AND FATTENING
The article discusses the features of the morphological blood composition of bulls depending on different systems of maintenance during intensive raising and fattening. The aim of the research was to assess the influence of various systems of keeping Simmental bulls on the morphological composition of their blood during intensive rearing and fattening. The study was conducted according to the traditional method of analog groups. The object was the bulls of the Simmental breed. A control group of bulls with tethered keeping and two experimental ones with a stable-pasture system were allocated. The number of animals in each group was 17 animals. The difference between the two experimental groups was in the technology of holding after weaning from mothers: in one group it was tied, in the other it was loose. In other respects, the conditions of the experiment were the same. The time frame of the experiment is from birth to 18 months. The average daily increments were determined from the experimental livestock, and blood samples were taken at certain intervals. The number of erythrocytes, hemoglobin, leukocytes, and eosinophils was determined in the blood. As a result of the experiment, an increase in the number of red blood cells was found in bulls of all groups by the end of the newborn period. The changes in hemoglobin content were similar to those of erythrocytes. The bulls of the control group in the first 6 months of life exceeded, although slightly, the peers of the experimental groups in terms of the number of leukocytes in the blood. A decrease in the eosinophils level in the blood of the third group's bulls indirectly indicates the development of a stress reaction in them. A similar phenomenon was found in the absence of tactile contact of the control group bulls with mothers during the newborn period. Intensive rearing of bulls of the second and third groups using the technology of beef cattle breeding provided a high intensity of their growth, and at the age of 6 months they reached a weight of 254.6 ± 2.8 and 253.4 ± 2.7, respectively, which is 27.4 and 26.8% (P<0.001) more than in the control group. However, the intensity of the growth of the bulls of the experimental groups after weaning them from their mothers at the age of 7 months significantly decreased, as a result of which the difference in live weight between the one-year-old bulls of groups 2 and 1 was 5.1 kg, or 1.2% in favor of the first. Since the decrease in the intensity of growth of group 3 bulls was influenced by the combined effect of weaning stress and growing them in conditions of loose confinement, at the age of 12 months they were inferior in terms of live weight to peers of the control group by 16.8 kg, or 2.8%. The living weight of 15-month-old bulls of the groups in ascending order of their ordinal numbers was 508.8± 6.7; 503.6± 6.3; 482.1 ± 6.5 kg, and at the end of the trial period - 588,7±8,1; 578,9±6,8; 553,6±7,5 kg.