Investigation of immunity of broiler chickens of Kobb-500 cross vaccinated by national associated viral vaccine and foreign (ABIC, Israel; Vitex XXI vek Seva) vaccines against Newcastle disease and infectious bronchitis was investigated in the conditions of the Republic of Belarus. In course of studies there was analyzed the content of immunoglobulin in blood serum, as well as the influence of living vaccines on immunity formation. Research results showed that broiler chickens immunization against Newcastle disease and infectious bronchitis by national and foreign vaccine produced by ABIC company made it possible to increase the phagocytic activity of pseudoeosinophils, bactericidalal and lysozyme activity of blood serum, that proved the activation of nonspecific protection factors. At the same time in blood serum there was stated the increasing of immunoglobulin number in 1,5-3,0 times in comparison with control groups. Economic efficiency of all analyzed vaccines was analyzed

Selection of an optimal dose of Cryptosporidium parvum agents which were isolated from swine and could cause expressed changes in organs of experimentally infestated mice was realized in the conditions of the Republic of Belarus. Data about on persistence of homoxenous coccidia Cryptosporidium parvum at laboratory white mice and pathomorphological changes in the bodies of experimental animals were presented. In a mucous coat of intestines there was marked a catarrhal inflammation with mucous membrane necrosis and its infiltration by leukocytes and macrophages.

Results of studying the efficiency of iodine containing preparation Jodon which was applied to highly productive cows with hypovarianism and to servicing bulls in order to increase their reproductive function realized in the Republic of Belarus were presented. On the basis of realized studies there was proved the considerable efficiency of Jodon preparation.

The historical and modem data on morphology of adrenal glands were analysed on the basis key historical manuscripts of XVII and XIX centuries were analyzed in the conditions of the Republic of Belarus.

Research results showed that in the conditions of correct organization and application of technological methods of livestock breeding and feeding it was possible to achieve high livability rate of sheep and lambs up to 90%. Also it was possible to get a substantial break of infection chain of many sheep diseases (especially those which had a respiratory nature). Research results showed that simultaneous application of convalescent-phase serum against sheep acute respiratory diseases, as well as Nitox 200 and Invamek for treatment of sheep and especially 2-3 month old lambs with respiratory infectious diseases promoted the recovery of 80-100% of animals.

It was established that in blood serum of pigs vaccinated against leptospirosis there was an authentic increasing of alanine aminotransferase, alkaline phosphatase and gamma-glutamyltransferase that made proved the presence of residual reactogenicity of biological preparations. In course of the experiment there were used 4 groups of swine which were administrated with 4 types of vaccines: 1. polyvalent vaccine produced in Belarus; 2. experimental thiosulfate vaccine in which there was used 30% sodium solution; 3. experimental emulsified vaccine; experimental emulsified + sodium + thiosulfate vaccine.

Development of a production technology of a national anthelminthic preparation Triclafen (from benzimidazole group) on the basis of triclabendazole and fenbendazole was realized in the conditions of the Republic of Belarus. As a result of realized experiments it was found that the developed suspension corresponded the requirements of pharmacopoeial items and can be applied for veterinary practice. Composition of different components with wide action spectrum made it possible to apply it against ruminant animals.

This article is devoted to a problem of biochemical interaction of selenium and antioxidational system of animals and people organism. The problem we have touched is about the efficiency of influence of organic and inorganic taking place on subcellular level. The advantages of organic selenium are proved, the degree of its bjochemical influence on an antioxidationi status of health are indicated.

Analysis of national studies and literary sources on problems of haemophilus pleuropneumoniae of swine was realized in the conditions of the republic of Belarus. Research was realized in the conditions of Agricultural Production Co-operative Uritskoe (Gomel region, Belarus). It was established that medical actions gave positive result only at early stages of disease.

Economic efficiency of immunization of piglets with a vaccine against a salmonellosis, pasteurellosis and streptococcosis in combination with 20% solution of sodium thiosulfate and Vitamin С as immune stimulators was analyzed in the production conditions of the Republic of Belarus.