Realized in the conditions of the Republic of Belarus studies showed that management of cultural landscapes should be based on the models which make it possible to present a proper evaluation of yielding capacity of different types of agricultural lands taking into consideration land quality and influence of natural and climatic factors. Dynamics of yielding capacity of green mass and application of mineral fertilizers at the natural and improved haylands of Belarusian Poozerye region was analyzed. There was noted a determinate variation of grass yields at pasture lands and plowing lands in various years. The presented mopdels made it possible to calculate the average yielding capacity of grasses cultivated at pasture lands and plowing lands in any year, as well as to forecast the extent of risk of yield capacity taking into account yield variability in different years. It was proposed to plan the production volumes of fodders for animal husbandry branch taking into account the variability of yielding capacity at various years under the influence of various unregulated natural and climatic conditions

Complex analysis of maize (Zea mays) yielding capacity and content of nutritive substances in silage and green mass depending on the phase of crop development and sowings damage due to frost was realized in the conditions of the Republic of Belarus. Yielding capacity of green mass in the analyzed sowings of hybrid maize Beliz on sod-podzolic light loamy soils was 75,1 n/ha at the stage of grain formation. Insufficient amount of positive temperatures at the beginning of vegetation stage was compensated by means of favourable weather conditions for growth and development of maize in July-September. In proportion to maize crops maturity there was stated the appropriate lowering of green mass. Taking place frosts lowered moisture content in crops. Yielding capacity of maize top biomass after cold spell was from 45,7 up to 44,8 c/ha. For the obtaining of the optimal amount of nutritive elements in the conditions of Vitebsk region of Belarus it was proposed to realize crop harvesting at the stage of milky-wax ripeness. The best composition of nutritive elements in silage was at the stage of milky-wax ripeness

Investigation of morphological changes in bone marrow of young hens in the conditions of application of associated virus vaccines and sodium thiosulphate immunostimulant was realized in the Republic of Belarus. The associated virus vaccine was applied against infectious bursal disease, infectious bronchitis, infectious laryngotracheitis, and Newcastle disease. Research results showed that under the influence of inactivated vaccine against mentioned above diseases there was noted the increasing of quantity of granulocytic cells, there was stated an active hyperplasia of pseudoeosinophil cells. Immunization of young hens with the presented vaccine developed in the Institute of Experimental Veterinary Medicine of the National Academy of Sciences of Belarus promoted a short-term increasing of leucoerythroblastic index. Application of an alternative vaccine developed by Scientific and Production Enterprise Avivak did not render substantial influence on the morphology of bone marrow of chickens. Sodium thiosulphate applied in combination with associated vaccines (in 7% concentration in vaccine) caused the hyperplasia of lymphoid and thrombocyte cells, strengthened the proliferation and maturity of granular leukocytes

Influence of monocalcium phosphate on natural resistance and clinical indexes of blood of breeding bull calves of white-and-black breed was realized in the conditions of the Republic of Belarus. Bull calves of the first (control) group in the composition of their main ration were fed with mixed fodder K-66-b, hay, green mass and as a balanced phosphoric-potassium additive they were fed with8 grams of defluorinated phosphate per 1 kg of mixed feed. Bulls of the second, third and fourth experimental groups in combination with the standard ration instead of difluoridated phosphate were fed with 5; 10; and 15 grams monocalcium phosphate per 1 kg of combined feed, respectively. Research results showed that application of fodder monocalcium phosphate in addition to the main ration made it possible to increase calcium and phosphorus content in blood of experimental bull calves. In the control group phosphorous content was 2,17 micromole, in the experimental groups – 2,40-2,78 micromole; calcium content – 2,50 and 2,58-2,88 micromole, respectively. The analyzed additive rendered positive effect on protein exchange, increased the natural resistance, bacterial growth-inhibitory activity in blood serum in the third, fourth and second groups on 50,3%, 42,5%, and 40,3%, respectively; lysozyme activity – on 46,0%, 39,2%, and 32,3%, respectively; phagocytic activity of leukocytes – on 21,9%, 25%, and 19,1%

Immunomorphological changes in young hens vaccinated with an associated inactivated emulsion vaccine against bursal disease, infectious bronchitis and Newcasle disease was realized in the conditions of the Republic of Belarus. Replacement young hens of 130-158 days old were divided into 2 groups with 200 head in each according the analogue principle. At the age of 130 days old the first experimental group of chickens was immunized against bursal disease, infectious bronchitis and Newcasle disease with a liquid inactive emulsion vaccine (produced in the republic of Belarus) in dose of 0,5 ml intramuscularly. In course of the experiment chickens from each group were killed on the third, seventh, fourteenth, twenty-first and twenty-eighth days. For the analysis of immunomorphological reaction there were tested tissue pieces from the places of vaccine administration, as well as thymus, bursa of Fabritius, lien, cecal tonsils and Garder's gland. Research results showed that in tissues in places of the vaccine administration there were developed hemorrhages, serous inflammatory edema, necrobiosis and necrosis of muscular fibers, inflammatory cellular infiltration, and moderate plasmocytic reaction. At a later stage at the places of damaged structures there was noted the development of granulation tissue with presence of some lymphoid nodules. In response to vaccination in the central organs of poultry immunity there was stated the sinuated changes of morphological indexes. Immunization of chickens against infectious bursal disease, infectious bronchitis and Newcasle disease promoted the increasing of absolute weight of lien, activation of blastic and plasmocytic reaction in bursa of Fabritius and lien and did not render substantial influence on immunomorphological indexes of cecal tonsils and Garder's gland

Morphological indexes in immune system organs of piglets which were vaccinated which were immunized by SPS vaccine (against salmonellosis (Salmonella), pasteurellosis (Pasteurella) and streptococcus) in combination with immunostimulative drugs and without them were studied in the conditions of the Republic of Belarus. Piglets of the first group were vaccinated against salmonellosis, pasteurellosis and streptoccocusis by SPS vaccine. Piglets of the second group were vaccinated by SPS vaccine in combination with vitamin C. Piglets of the third group were vaccinated by SPS vaccine with immunotstimulant sodium thiosulphate. The fourth (control) group of animals was administrated with normal saline. Animals were immunized twice, intramuscularly with 7 day interval and in dose 4 ml (primary), 5 ml (secondary). Vitamin С was added in dose 0,05g per head. Research results showed that immunization by SPS vaccine with sodium thiosulphate and Vitamin С activated the morphological reaction of immune system. Application of Vitamin С and sodium thiosulphate (30% concentration) in combination with SPS vaccine promoted the increasing of lymphoid nudels in lymphodnudus and lien, increasing of plasma cells quantity in 1,3-2,2 times, activation of micro- and macrophage reaction in 1,5-2,8 times in comparison with vaccinated animals

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

Experimental application of a vaccine against salmonellosis, pasteurellosis, and streptococcosis (SPS) for piglets of 30-35 days was realized in the conditions of the Republic of Belarus. Research results showed that administrationof sodium thyosulphate and vitamin С in combination with SPS vaccine promoted the statistically-valid increasing of preventive properties of blood serum of piglets and increasing of titers of specific antibodies to agents of pasteurellosis and a salmonellosis in 1,3-2 times, as well as increasing in blood serum of quantity of immunoglobulins and to reduction of quantity of globulins.

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.

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.