The article covers materials of retrospective and current analysis of epizootic situation of rabies on the territory of Belarusian Polessye. During 64-year period (1958–2021) 5,871 cases of animal diseases by rabies have been diagnosed in this territory. Rabies was established in 29 animal species. Dominant place among sick animals is occupied by fox – 44, 6 %. Domestic animals are the main source of infection of the population.

The genome of mycobacterium tuberculosis (MBT) was detected in the milk of cows from conditionally tuberculosis-free herds that did not react and gave an uncertain reaction to tuberculin in 53.3 % 66.7 % of cases, specific antibodies in 40.7 % and 57.1 %, MBT antigens in 25 % and 22.2 % of samples, and non-acid-fast forms of MBT were detected from 92.3 % and 66.7 % of the studied milk samples heated at 98 oC. Taking into account the absence of signs of active disease, this indicated a latent tuberculosis infection in some cows that did not respond to tuberculin and that the tuberculin test did not reflect the real situation in the herd. To eliminate tuberculosis infection, it is necessary to use alternative methods for determining direct and indirect markers of tuberculosis infection and the development of a new system of anti-tuberculosis measures that take into account the high probability of transmission of modified forms of MBT through the placenta and with milk.

The DNA of Mycobacterium tuberculosis (MBT) was found in the milk of cows that did not reacted to tuberculin. After 10 hours of warming up at 98 °С cell wall deficiency (CWD) mycobacterium tuberculosis was isolated from 50% of samples of such milk.
Strains of CWD MBT withstood 5 hour warming up at 98 °С.
The morphology of cells naturally changed during warming, their acid-fastness increased up to the appearance of completely acid-fast cells. Sowing of warmed suspensions on a special nutrient medium in all cases gave growth of CWD MBT which did not differ from the initial strains, which confirms the unique thermal stability of MBT and indicates that even such extreme thermal exposure does not solve the problem of biosafety of milk.

Design of antibody-antibiotic conjugates with doxycycline immunocompetent to Escherichia coli is proposed. The egg yolk immunoglobulins from hens immunized with Escherichia coli have been conjugated with the antibiotic using the glutaraldehyde as the crosslinking reagent. The reaction of conjugation was followed spectrophotometrically and revealed the formation of distinct absorption bands in ultraviolet regions. The kinetic analysis of forming the conjugates by the Guggenheim method showed that the conjugation reaction obeyed the kinetics of the first-order reactions. The velocity constant equaled 0,77 min^-1. The half-conversion period of immunoglobulins during conjugation with glutaraldehyde was about 1 min. The reaction was rapid in aqueous solution at room temperature. The molar ratio of doxycycline: antibody in the conjugate was 2:1.

In the course of the experimental work, it was found that the concentration of phospholipids and an aqueous solution of activated potassium humic substances affects the viability of bovine and human sperm.
Phospholipids included in the composition of the diluent up to 10.0 and 20.0 mg, after 5 hours of incubation at a temperature of (37±1) °C, provide the survival rate of bull and human sperm at 34.4±0.86–35.5±0.86 % and 36.2±0.86–32.4±0.86 % germ cells, respectively.
Diluents containing 0.0025 % aqueous solution of activated potassium humate and 10.0 and 20.0 mg of phospholipids provide the highest survival rate relative to the baseline in bovine and human spermatozoa, respectively, up to 72.9–78.8% and 73. 4–76.2 %.

The article presents the results of the research on the peculiarities of embryo and morphometric development of the eggs isolated from the gonads of female nematodes Heterakis gallinarum that parasitize turkeys and hens at different intensities of invasion in case of mono-and mixed forms of helminth infections. It was established that the eggs of H. gallinarum became invasive at 30 °C for 7 days, their survival rate in the laboratory conditions was: 80,67±2,08 % (turkeys), 84±3 % (chickens). The morphometric parameters of eggs excreted by mature H. gallinarum females are objectively influenced by such factors as the stage of biological cycle, the intensity of invasion, the type of host.

 The article describes the methods of isolation of fibroblasts from the musculoskeletal tissue of a cow embryo for practical use in veterinary medicine as part of the application of new medical technologies. The morphological characteristics and functional activity were studied the viability of  musculocutaneous fibroblasts was assessed. 

 The article presents data on the qualitative and quantitative assessment of DNA/RNA obtained using three different isolation kits. Comparative results of PCR with primers for three bacterial and two viral infections are presented. A  comparative assessment was carried out. 

 Domestic PCR systems have been designed to detect the genomes of the pathogens of actinobacillary pleuropneumonia and hemophilic polyserositis,  screening of nucleotide sequences has been carried out, specific primers have been selected, and PCR parameters have been worked out. Sensitivity, specificity and repeatability results are given. 

 The article presents the results of toxicological studies of a new veterinary drug intended as a therapeutic and prophylactic agent for cryptosporidiosis of calves. It is established that the test sample belongs to hazard class 4 (low-hazard substances). 

The article contains a review material on the level of microbial contamination of the milk-carrying sections of the transport system of the 2ADS-N (milk pipeline), Merry-go-round, Herringbone and Parallel milking plants.
The differences in the level of bacterial contamination of the surfaces of components and parts in contact with milk, depending on the volume and structural features and types of materials used for their production, have been noted. The critical contamination limits have been identified that allow taking timely corrective actions to mitigate potentially dangerous biological risks in accordance with the HACCP principles.
It is indicated on the necessity of investigation of microbial contamination of milk hoses for pumping milk from the milking parlor to the cooling tank and milk hoses for pumping milk from the cooling tank to the milk delivery truck, as well as the correction of sanitary treatment regimes for these types of products.