In the conditions of the Republic of Belarus there was produced a trial series of hyperimmune serum against livestock animals colibacillosis and there was realized the quality control of the analysed biological preparation. Research results proved that the developed serum was sterile, safe and had high immunogenetic activity. In course of quality control there were considered the following indexes: determination of physiognomy, colour, presence of visually accessible particulate matters; determination of safety and harnfullness; determination of activity; determination of concentration of hydrogen ions; determination of sterility; determination of serum volume in consumption package. For serum production there were used strains E.coli O9, O78, O0, O117, O26, O139, O15, O41, O55, O115, O141, O8, K88, K99, F41, 987P. For the production of trial series there was realized cultivation of Escherichia on the special nutritive media. There used bulls as serum producers

Studying of cultural, morphological and enzymatic properties of isolated from a calf strain Salmonella enteritidis was realized in the conditions of the Republic of Belarus. There was presented quantity and results of bacteriologic examinations for cattle salmonellosis realized in the district veterinary services in Belarus in course of three years. There was presented quantity and results of serovars of salmonellas isolated from the pathologic material from cattle obtained in course of three-year analysis: S. typhimurium, S. enteritidis, S. dublin, S. panama. The following enzicymatic properties of the studied strain were analyzed: glucose, sucrose, manna sugar, citrate, methyl red, Voges-Proskauer reaction, mobility, indole, sulphuretted hydrogen, and urea. Determination of antibiotic susceptibility of strain S. enteritidis was presented. Initial data for calculation LD50 was given. Research results showed that the studied microorganisms were the representatives of family Enterobakteriacea, genus Salmonella, species S. enteritidis

Analysis of manifestation of chlamydial infection of cattle in the conditions of forage affect with mycotoxins was realized in the conditions of the Republic of Belarus. Research results showed that chlamydial infection proceeded in association with aflatoxin, T-2 toxin, deoxynivalenol, zearalenone and ochratoxin. In course of the biochemical analysis there was noted the lowering of carotene on 23%, and vitamin A – in two times; also there was slight lowering of alkaline reserve. The obtained data proved the substantial changes in content of sub-populations of lymphocytes in cow blood in dry and postnatal period. During the immunological study of immunoglobulins in blood serum of cows sick with postpartum chlamydial endometritis it was revealed that titre of immunoglobulin A was on 31% higher. Level of immunoglobulins G and M differed slightl

Determination of the optimal doses of monocomponents of the developing vaccine against rotavirus infection and cattle colibacillosis was realized in the conditions of the Republic of Belarus by the example of 80pregnant cows with body weight 400-450 kg. Immunological efficiency of the analyzed preparations was estimated in accordance with ascending rate of titres of specific antibodies before and after vaccination. Research results showed that the highest degree of expressed immunologic response to the monocomponents was stated for cows vaccinated in dose 2,5 cm3. Increasing of dose up to 5,0 cm3 did not render substantial influence on gain of specific antibodies level in blood serum of immunized cows. Decreasing of dose up to 1,0 cm3 caused to less intensive biosynthesis of antibodies, excluding animals which were administrated with antigen E. coli K88. In the majority of experimental groups of cows in blood serum there was stated the increasing of specific antibodies level after the second administration of the components. The obtained results proved the necessity of dualfold administration of the developing biological preparation. In course of study there was determined the choice of monocomponent doses of the vaccine. The optimal dose of monocomponent against cattle rotavirus in case of infection titre 7,0 lg 50% tissue cytopathic dose was 2,5-5 cm3 pr animal. The highest titres of the specific anticolibacillosis antibodies for E.coli with concentration of bacterial cells 10E9/ml for K99 and A20 in the conditions of antigen administration in dose 2,5 cm3, and for E.coli with adhesive antigens K88 - 1,0 cm3