The problem of creation of improved conditions for cattle oocyte maturation in vitro was studied in the Republic of Belarus. The objects of study were cattle oocytes and embryos of early preimplantation stages of development obtained in vitro conditions. Research results showed that application of bovine serum in complex with embryonic or fetal serum in the process of oocyte cultivation in vitro conditions made it possible to obtain 35,5-44,8% of breaking down cells and 16,1-17,2 % of embryos at the stage of morula-blastocyte. Entering of 0,02 ng/ml of gonadotropin-releasing hormone (Surfagon) into media for oocyte maturation at the cost of regulation of the processes of growing and development of oocyte-cumulus complexes made it possible to increase of yield of matured till the stage of metaphase II oocytes up to 89,3 %. At the same time, the yield of divided embryos after fertilization increased on 2,5 % in comparison with control indexes and amounted 45,2 %. Research results showed that the synthetic phytohormone epibrassinolide could be used as a biologically active factor in the process of getting early embryos in vitro in concentration of 2 x 10E-7 – 2 x 10E-9 mole/l. It made it possible to get 46,4-55,0 % of divided cells and 14,2-16,2% preimplantation embryos

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

Investigation of spreading of diseases of micronutrient deficiencies at cow breeding farms of Grodno district of the Republic of Belarus depending on the season and character of polymicroelementoses, as well as the determination of relations between polyhypomicroelementoses and state of new born calves were realized. Clinical investigation of 1350 milked and calf-bearing dry cows and biochemical analysis of 450 blood samples taken at nongrazing time (before cows pasture) and at pasture time were conducted. The following animal groups were selected: the first group – cows after calving; the second group – the cows of three month pregnancy; the third group – calf-bearing dry cows. The following groups were selected among calf-bearing dry cows in nongrazing and pasture time: clinically healthy cows, which had biochemical blood changes, showing development of subclinical polyhypomicroelementoses (n = 20); clinically healthy cows with blood indicators, standing in limits of physiological standards. Number of calves was considered after calving of cows of both groups. Body weight, realization of staying and sucking position, evidence of sucking reflex, and calves disposition to neonatal pathology were considered in the study. Research result showed that cow microelementoses were marked by the development of subclinical polyhypomicroelementoses. Among cow polyhypomicroelementoses there was noted the domination of states followed by lowering of zinc, cobalt and cuprum content. Polyhypomicroelementoses were developing both in winter housing season and in course of grazing season. Polyhypomicroelementoses involve cows of different physiological states and were spreading more intensively at cow dry period and after calving. Calves obtained from cows with polyhypomicroelementoses often had the state of hypotrophy and high incidence of dyspepsia at colostric period. Clinical and biochemical status of the analyzed calves was characterized by signs of intoxication and hepatic insufficiency

Studying of toxicity of enterosorbent produced the basis of mixture of filtering pulvis of perlite, kizelgur and activated carbon was realized in the conditions of the Republic of Belarus by the example of healthy white mice of both sexes with body weight of 18-25 grams. Animals were divided in three groups. The tested substance was entered insitu to ventricle on an empty stomach after 12-hours of absolute diet. The first group animals were administrated the enterosorbent in doze of 5 g/1 kg, the second group animals - 2,5 g/1 kg. Glucose content increased from 3,8 +/- 0,47 to 4,3 +/- 0,17 mmol/l on the 30-th experimental day and decreased on 8,2 % on the 60-th experimental day. Cholesterin and triglyceride content lowered on 9,5 % and 11,1 %,respectively. Enzymes concentration of aspartate transaminase and alkaline phosphatase decreased from 120,0 +/- 3,87 up to 117,0 +/- 2,58 units/l and from 396,3 +/- 3,78 to 345,3 +/- 2,97 units/l, respectively. Urea increased from 3,7 +/- 0,16 to 3,9 +/- 0,17 mmol/l on the 30-th experimental day. Research results showed that mixture of filtering pulvis after the single oral administration in dose of 2,5-5 g/1 kg did not cause mice death. The analyzed mixture could be referred to the class of low-toxic substances. The mixture did not have irritation action and did not render chronic toxic action on the experimental mice

Scientific and production examination of feed additive Semerik-Vita containing iodine and selenium was realized in the conditions of the Republic of Belarus by studying of its influence on production and economic indexes of laying hens and their products, as well as by studying of its influence on clinical state and biochemical blood indexes of poultry. Research results showed that application of feed additive Semerik-Vita made it possible to increase of egg producing ability intensity on 1,8 %, egg yield - on 2,4 % in the conditions of lowering of feeding expenses on 1,4 %. Application of the analyzed feed additive made it possible to obtain a new kind of eggs fortified with iodine, selenium, beta-carotene and vitamins (A, E, C, PP, B1, B2, pantothenic acid and folic acid). In eggs of poultry of experimental group the content of selenium increased in 2,1 times, iodone - in 1,5 times, vitamin E – in 3,9 times, beta-carotene – in 1,4 times, vitamin A – in 1,3 times, pantothenic acid – in 1,2 times, vitamin C – in 1,17 times, vitamin PP – in 1,4 times, vitamin B1 – in 1,5 times, vitamin V2 – in 1,4 times, folic acid - in 1,5 times in comparison with eggs of laying hens from the control group. Research results proved that application of Semerik-Vita did not render negative effect on the clinical indexes of laying hens. It made it possible to lower the content of urea acid in 1,7 times, as well as to increase the content of triglycerides in 2 times, cholesterol - in 2,4 times, magnesium - in 1,28 times

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

Research of immune activity of an experimental series of inactivated vaccine against swine pasteurellosis (Pasteurella) with application of adjuvants of Sepptic Montanida ISA 70 and Montanida ISA 206 was realized in the conditions of the Republic of Belarus. In the capacity of water phase there were used serovars A, B, and D Pasteurella multocida. Research results proved the possibility of application of adjuvants of Sepptic company for the development of vaccine against pasteurellosis. The vaccine with the presented adjuvants after its application did not cause after-trouble effects. In course of immunization there was noted the formation long-lived continuous immunity that was proved by high titres of specific anti-bodies in blood serum in all experimental groups of piglets. Single application of the proposed vaccine in doses 2 or 3 ml per animal proved to be effective. Also it was efficient to apply it twice in doses 1 and 2 ml per animal. For the vaccine production it was proposed to use adjuvant Montanida ISA 206 which did not have high reactogenicity

Analysis of the optimal scheme of doses and rates of combined administration of probiotic Dialakt and immunostimulant Alveozan was realized in the conditions of the Republic of Belarus by the example of 1500 broiler chickens of cross Kobb- 500. Chickens of the first (controlled) group were given only total ration, balanced with the main nutrients. For the chickens of the second group were administrated with immunostimulant Alveozan with water starting from one day old age, every day in dose of 10 mkg/kg of body weight once a day in course of 5 days successively and with 7 days interval till the end of growing period; and probiotic Dialakt was administrated with water in dose of 0,1-0,2 ml/head (10,0-20,0 mln microbial bodies) starting from one day old age, once a day in course of 5 days successively and with 6 and 14 days intervals till the end of growing period. Chickens of the third group were administrated Alveozan in dose of 10 mkg/kg of body weight with drinking water once a day in course of 5 days with 10 days interval till the end of growing period; and Dialakt in dose of 0,1-0,2 ml/head with drinking water starting from one day old age, every day in course of 5 days with 6 and 14 days interval till the end of growing period. The research results showed the following optimal regime of complex application of the analyzed preparations: immunostimulant Dialakt - in dose of 0,1-0,2 ml/head with drinking water starting from one day old age, once a day in course of 3 days successively with 6 and 14 days intervals till the end of growing period; and immunostimulant Alveozan - in doze of 10 mkg/kg of body weight with drinking water once a day in course of 5 days with 10 days interval till the end of growing period. Complex application of Dialakt and Alveozan promoted the increasing of organometric indexes, specific volume and size of thymus in 1,5-1,8 times (P less than 0,01), Fabritsiya bursa - in 2 times (P less than 0,01) and lien - on 11,1% (P less than 0,05)

Scientific experiments on determination of the optimal doses kizelgur for import substitution of shells in poultry diets was realized in the conditions of the Republic of Belarusby an example of 4 groups of laying hens of Khajseks korichnevyj cross. Hens of the first (controlled) group were given full ration applied at the tested poultry farm which included 5% of shells. Hens of the other three experimental groups were given complete feedstuffs with inclusion of mineral feed kizelgur: hens of the second group – in dose 2% out of dry matter mass; third group - 3%; for the fourth group - 4%. The research results showed that application of mineral feed additive kizelgur increased hen productivity in experimental groups on 2,8%; 5,9%; 7,2%, respectively. In the experimental groups there was an increasing of egg yields on 2,8%; 5,9%; 7,2%, respectively. The best indexes of poultry livability were stated in the third group (on 5,5% higher than in control). The similar tendency was stated in course of analysis of egg weight, shell thickness and calcium content of shell. Kizelgur application led to increasing of egg mass in tested groups: on 0,46% (2 group), 1,6% (3 group) and 2,4 % (4 group). At the age of 340 days shell thickness in experimental groups was on higher 3,3% (2 group), 0,7% (3 group) and 8,7 % (4 group) than in control. The analyzed additive increased the natural resistance of hens that was proved by indexes of bacterial growth-inhibitory activity of blood serum and lysozyme activity. There noted tendency of total protein increasing. Studying of immunological indexes showed that they were the most evident in the fourth experimental group

Studying of efficiency of application of modified scheme of hyperimmunization of bull-producers with a designer salmonella polyantigenin in comparative analysis with the production scheme of hyperimmunization was realized in the conditions of the Republic of Belarus. Research results showed that engineered polyvalent antigen for hyperimmunization of producer bulls contained in their formula the following serovariants of salmonella in 1:1 ratio: S. typhimurium 371, S. dublin 373, S. choleraesuis 370, and S. enteritidis CB. The obtained antigen was sterile, harmless and had pH 7,3. Hyperimmunization of producer bulls in the experimental scheme revealed in increasing of leukocytes quantity on 57,3 %, banded neutrophils on 86,7 %, B-lymphocytes - on 42,2 %, content of total protein - on 25,6 %, content of Ig G - on 77,8 %, lg M - on 51,6%. After the fifth administration of antigen there was stated the lowering of agglutinating activity of blood serum on 25%, content of Ig G - on 54,4%, Ig M - on 14,6 %, that indicated to the inefficiency of antigen administration and became the basis for termination of hyperimmunization cycle. Immunobiological reaction of bull-producers which were hyperimmunized by the suggested scheme differed from reaction of animals which were hyperimmunized by the production scheme: content of total protein increased on 10,1%, protein content - on 27,3 %, content of lg G - on 24,8 %, lg M - in 23,7%