When introduced into the respiratory system of young cattle, the pathogen overcomes natural protective barriers and interacts with the cells of the respiratory epithelium. At the same time, antimicrobial protection of the bronchopulmonary tract is activated and phagocytic cells (macrophages and neutrophils) are attracted to the site of inflammation. Produced antibodies and cytokines activate phagocytosis and destroy foreign agents. The regulation of the inflammatory response in bronchopulmonary pathology depends on complex interactions between immune cells and anti-inflammatory cytokines. Moreover, changes in the T cell component of immune system lead to a violation of the ratio between the cellular and humoral components of immunity. Among non-communicable diseases, up to 60% are the respiratory system diseases of young cattle. In this material, we will examine the Dorynum medication obtained by modern methods of biotechnology and engineering.
To assess the therapeutic effect of Dorynum manufactured by Farvet, production tests of the drug were carried out in the Pobeda collective farm of the Lipetsk Region, which is considered to be trouble-free in relation to infectious, viral and parasitic diseases.
By the analogues principle, two groups of 45-55-day-old calves with bronchopneumonia were formed, with ten animals in each group. The test group was administered Dorynum at a dose of 10 mg/kg of live weight with an interval of 24 hours. The immunostimulating effect of Dorynum during vaccination was studied on two groups of 45-60-day-old calves, with 10 animals in each group. All animals were vaccinated against pasteurellosis with an emulsified vaccine. The experimental group of calves, together with the vaccine, was subcutaneously administered Dorynum at a single dose of 7 mg/kg. The results of a clinical study showed that when Dorynum is included in the combined treatment of calves with bronchopneumonia, the first injection leads to reduction in cough, and the second one improves the general condition; the recovery is reached five days earlier than in the control group. The clinical effect is accompanied by positive dynamics in hematological parameters (table).
Serological data from calf serum. Table 1
Indicator
| Beginning of the experiment
| End of experiment
|
| Group
| Group
|
| Experimental
| Control
| Experimental
| Control
|
Red blood cells, 1012/l
| 2.5
| 5.5
| 5.98
| 5.85
|
White blood cells, 109/l
| 7
| 7.2
| 7.4
| 7.72
|
Hemoglobin, g/l
| 100
| 99.67
| 101
| 98.25
|
Total protein, g/l
| 61.83
| 59.9
| 77.05
| 64.7
|
Normal agglutinins titer in AT
| 1:8
| 1:8
| 1:64
| 1:32
|
Gamma globulins
| Turbidity units
| 19.4
| 20.2
| 23.65
| 20.15
|
G%
| 1.83
| 1.91
| 2.86
| 1.91
|
Serum bactericidal activity, %
| 64.97
| 62.1
| 88
| 74.5
|
Phagocytic activity of neutrophils (% of phagocytosis)
| 52.12
| 51.5
| 86
| 74
|
The Table shows that in the blood of animals of the experimental group on the 21st day following the administration of Dorynum, the amount of total protein increased, while in the control group this indicator was below the physiological norm. Also, the content of gamma globulins in experimental animals increased to 2.86 g/%, the serum bactericidal activity rose up to 88%, the phagocytosis activity - up to 86%; the indicators of the control group amounted to 1.91%, 74.5% and 74%, respectively. Changes in CBC of the experimental group calves is an important criterion for evaluation of effectiveness of the test drug. In an experiment to study the immunocorrective effect of Dorynum during the vaccination of calves against pasteurellosis, an increase in antibody titer was observed on the day 30: in the experimental group the titer range was from 1:64 to 1:128, in the control group - from 1:32 to 1:64. There were no complications or side effects after administration of the drug.
On the basis of the conducted research, the following conclusions can be drawn:
- The use of Dorynum in the treatment of bronchopneumonia improves the general condition of calves, normalizes hematological parameters of the total protein, increases the content of hemoglobulins, the level of serum bactericidal activity and the phagocytic activity of neutrophils.
- After the second injection of Dorynum, the clinical condition of the calves significantly improves, and the recovery occurs five days earlier than usual.
- The simultaneous administration of Dorynum with the pasteurellosis vaccine doubles the antibody titer as compared to the control group.
The analysis of the data obtained during the experiment indicates that Dorynum should be used in the combination therapy of bronchopneumonia in young cattle, as well as an immunostimulant during vaccination. The experience of using Dorynum in veterinary practice confirms that it is a necessary component of comprehensive treatment against various diseases in animals.
M.I. Stepanov, Honored veterinarian of Russia Dorynum administration at bronchopulmonary pathology in calves.