In the conditions of the Republic of Belarus there was created an adhesive antigen on the basis of bacterial suspension of Escherichia which were separated from culture media by means of purification and concentration on membranes UMP-300 and UMP-5 that made it possible to obtain a cleaned-up preparation the specific activity of which was in 2-4 higher that of the unpurified one. In course of the study there was developed a method of purification and concentration of adhesive Escherichia antigens with the help of membrane technology. There were obtained biologically active adhesive antigens E.coli K88, K99, F41, 987P; there were selected the ultrafiltration membranes providing the optimal selectivity and productivity of the process; there were studied the influence of some factors on the process of adhesins concentration by means of ultrafiltration method. During the experiments there was analysed the agglutinating activity of antigents prepared by different methods.

Realization of veterinary and sanitary examination of meat and slaughter products of calves treated with hyperimmune serum against cattle colibacillosis was conducted in the conditions of the Republic of Belarus. There were formed two groups calves of 3-5 days old. Calves of the first group were treated with serum biological preparation of trial series produced at Vitebsk Biofabrika (Belarus). Calves of the second group were intact animals. Calves of each group were killed in 14 days after preparation application for realization of veterinary-sanitary examination. Slaughter meat was studied in accordance with the following indexes: pH; peroxidase activity; presence of products of primary protein breakdown; moisture content; relative biological value of meat; bacterial examination. The research results of organoleptic indicators showed that meat of both groups corresponded to the standards. Hyperimmune serum against colibacillosis of live-stock animals did not render negative influence on organoleptic, physical and chemical indexes of meat. Indexes of the relative biological value in meat of calves treated with the examined serum were higher than the similar indexes of intact animals. Meat of all examined animals did not have any germs of toxico-infections and toxicoses

The realized studies of an experimental series of inactivated vaccine showed that the developed biological preparation made it possible to achieve high preventive efficiency in the conditions of cows heavy with calves for the creation in newborn calves the expressing immunity after milk feeding in the first hours of their life. As a result realized in the conditions of the Republic of Belarus production experiment of emulsified vaccine against rotavirus infection and colibacillosis of cattle in animal breeding farms of different regions of the Republic the prophylactic efficacy of a developed vaccine made up 97,9-98,9%. Research results showed that the developed inactivated vaccine caused at the immunizated animals the formation of specific antibodies at a higher level in comparison with other analyzed national and foreign analogue preparations.

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

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