In the conditions of the Republic of Belarus annually in 25-50% of total number cattle there was stated ketosis (milk fever); as a result, from each cow in cattle breeding farms receive less milk per lactation on 10-15%, as well as there is a lowering of fat and protein (and biological value) content in milk. In course of the study there was analyzed the influence of mineral and energy supplement Felutsen K-1-2 for the preventive treatment of ketosis of highly productive cows. Research results showed that application of the analyzed additive rendered the positive influence on morphological and biochemical blood indexes. In particular, there was an increasing of hemoglobin level, content of total protein, albumins, magnesium, calcium, and phosphorous. It also rendered positive influence on lipid exchange. In course of the study it was marked, that the prophylactic efficacy of mineral and energy supplement Felutsen K-1-2 in the experimental groups was 100%, and the control one – 80%.

In the conditions of the Republic of Belarus there were analyzed the peculiar features of morphology of bursa of Fabricius of turkeys broad-breasted white turkeys at the stage of postnatal ontogenesis. Research results showed that postnatal ontogenesis of bursa of Fabricius of turkeys developed irregularly with preservation of organ up to 220 days. At turkeys in 300-day old age the organ preserved only in 45% of bird units. Form, colour and consistency of bursa of Fabricius depended on bird age. The absolute weight of the organ increased up to 220 days. The relative weight was maximum at 20-day old age. The sexual peculiar features of the organ morphology were insignificant; they revealed after the beginning of sexual maturity and expressed by some difference in weight and linear dimensions.

In the conditions of the Republic of Belarus there was analyzed the efficiency of bactericidal action of tartaric acid aerosol for air sanitation of poultry buildings and increasing of broiler chickens viability. The bactericidal action was analyzed by the example of Staphylococcus aureus, Eschericia coli and Proteus vulgaris. In course of study there were analyzed biochemical indexes of blood and blood serum, lymphoid tubercle in proper mucous plate of trachea of broiler chickens after 6-time treatment with tartaric acid and Ekotsid C preparation. Research results showed that the analysed preparations did not render negative influence on metabolic indexes of broiler chickens and increase poultry viability. Application of tartaric acid did not cause pathomorphologic changes in tissues and organs of birds, stimulated the active proliferation of leucocytes in immune system organs (thymus gland; spleen; and lymphoid tissue).

In the conditions of the Republic of Belarus there was determined the influence of nutritional medium composition on pathogenic properties of leptospirosis bacteria, by an example of 6 pathogenic strains: Leptospira pomona; Leptospira tarassovi; Leptospira grippothyphosa; Leptospira icterrohaemorragia; Leptospira conicola; Leptospira hardjo. During the study there were used the following media: serum-supplemented vitaminized medium on the basis of buck serum; serum-supplemented medium with a growth factor; serum-supplemented vitaminized medium with antlbody biosynthesis growth factor; semisynthetic Russel's medium. According to the results of realized studies there was developed a correlation between terms of leptospirosis bacteria survivability in laboratory animals depending on cultivation medium. In course of the study there were analyzed terms of Leptospira persistence in guinea pigs.

The research was realized by an example on 30 chickens aged 1, 10, 20, 30 60-days old, and 10 hens: 4-months, one-year-old and 2-year-old in the conditions of the Republic of Belarus. All poultry stock was maintained in the conditions of industrial production at the Gorodokskaya Poultry Farm of Vitebsk region (Belarus). As a result of the study there was revealed a certain pattern of variation of a quantity of active forms of enzymes in organs chickens of different age. Application of histochemical methods made it possible to reveal different levels of metabolic processes in cellular elements of thyroid gland, which demonstrated the habit of formation and functioning of the organ at different stages of postnatal ontogenesis in hens. Coefficients of acid phosphatase activity in thyrocytes of thyroid gland of hens and indexes of alkaline phosphatase activity in secretion forming cells were analyzed. | Исследование провели на 30 цыплятах в возрасте 1-, 10-, 20-, 30- 60-дней, и 10 курах: 4-месячные молодки, годовалые и 2-летние особи. Все поголовье птицы содержалось в условиях промышленного производства на Городокской птицефабрике Витебской области. В результаты исследований установлена определенная закономерность изменения количества активных форм ферментов в органах птиц разного возраста. Использование гистохимических методов позволило выявить разные уровни метаболических процессов в клеточных элементах щитовидной железы, которые демонстрируют характер становления и функционирования органа на разных этапах постнатального онтогенеза кур. В табличной форме представлены коэффициенты активности кислой фосфатазы в тироцитах щитовидной железы кур и показатели активности щелочной фосфатазы в секретообразующих клетках.

On the basis of realized in the conditions of the Republic of Belarus research it was established, that Cryptosporidial infection was found at adult and young pigs. The data on influence studying cryptosporidiosis invasion on pathomorphological changes in internal organs of piglets in the conditions of an associative course with infectious. Associative diseases give clearer clinical findings and proceed much harder, with heavier morphological changes. The majority of diseases in the conditions of an associative course proceeds harder in comparison with a mono-infection or invasion. In the conditions of mono-invasion the basic changes are localized in small intestines, causing acute and subacute catarrhal enteritis and a serous inflammation of regional mesenteric lymphonodus. These histological processes are presented as non-uniform locus of infection of a mucous membrane of intestines with atrophy of villus, hypertrophy of crypth and mononuclear polymorphic-nuclear infiltration of basal membranes. In the conditions of association of Cryptosporidial infection with infectious diseases it was noted that the pathomorphological changes progress and are showed not only by catarrhal, but also by hemorrhagic and local necrotic enteritis. Epithelium of mucous membrane is exposed to desquamation, intestines walls become thinner because of meteorism. Thick intestines are also involved into inflammatory process. Associations of Cryptosporidial infection with infectious diseases lead to development of severe pathomorphological changes in intestines. Alteration has prevailing character that is expressed in progressive development of atrophic, dystrophic processes and decline of cells and tissues that conducts to increase of permeability of vessels and proliferation of cells of reticuloendothelial system. | На основании проведенных исследований установлено, что криптоспоридиозная инвазия выявляется у поросят. Представлены данные по изучению влияния инвазии криптоспоридиоза на патоморфологические изменения во внутренних органах поросят при ассоциативном течении с инфекционными болезнями. Ассоциативные заболевания дают более яркую клиническую картину и протекают гораздо тяжелее, с более выраженными морфологическими изменениями в организме. Большинство болезней при ассоциативном течении протекает более тяжело в сравнении с моноинфекцией или инвазией. При моноинвазии основные изменения локализуются в тонком кишечнике, вызывая острый и подострый катаральный энтериты и серозное воспаление регионарных брыжеечных лимфоузлов. Гистологические данные процессы представлены, как неоднородные участки инфицирования слизистой оболочки кишечника с атрофией ворсинок, гипертрофией крипт и мононуклеарной полиморфнооядерной инфильтрацией базальной мембраны. При ассоциации криптоспоридиоза с инфекционными заболеваниями патоморфологические изменения прогрессируют и проявляются не только катаральным, но геморрагическим и очаговым некротическим энтеритами. Эпителий слизистой оболочки подвергается десквамации, стенки кишечника истончаются вследствие метеоризма. В воспалительный процесс также вовлекается толстый кишечник. Ассоциации криптоспоридиоза с инфекционными заболеваниями приводят к развитию в кишечнике тяжелых патоморфологических изменений. Альтерация имеет преобладающих характер, что выражается в прогрессивном развитии атрофических, дистрофических процессов и некроза клеток и тканей, что ведет к повышению проницаемости сосудов и пролиферации клеток ретикулоэндотелиальной системы.

In the conditions of the Republic of Belarus there was analyzed the influence of mycotoxins on state of energy metabolism and development of energy deficient states of bred and milking sows maintained in the production breeding conditions. Clinical status of sows was characterized by concurrent mycotoxicoses. As a result of action of mycotoxins in sows there was developed an energy deficiency and state of acidosis. The mentioned above changes played an important part in the pathogenesis of mycotoxicosis. There were presented the following results: analysis of groups of pregnant sows and suckling-pigs; the content of mycotoxins in mixed fodders; symptoms revealed at sows and pigs; indexes of carbohydrate and lipide exchanges in blood of sows; the content of trace elements in blood of sows; gas composition of sow blood. | Исследования проведены на супоросных и подсосных свиноматках, содержащихся в условиях промышленной технологии. Клинический статус свиноматок характеризовался сочетанным микотоксикозом. В результате действия микотоксинов у свиноматок развились энергодефицит и состояние ацидоза. Данные изменения являются важной составной частью патогенеза при микотоксикозах. В табличной форме представлены группы супоросных и подсосных свиноматок, содержание микотоксинов в комбикормах, симптомы, выявленные у свиноматок и поросят, показатели углеводного и липидного обменов в крови свиноматок, содержание макроэлементов в крови свиноматок, газовый состав крови свиноматок.

In the conditions of the Republic of Belarus there was studied the formation of nonspecific protection factors of the first year foals. By a principle of conditional analogues there was generated a group of clinically healthy foals at which monthly from bulbar veins there were taken tests of blood for hematological and biochemical analysis. From the obtained data it was visible, that within the first year of foal life there were taking place the processes of formation of nonspecific protection factors of an organism which were accompanied by a gradual increasing of quantity of erythrocytes, haemoglobin, leukocytes, certain change in the diagramme, and also increasing of bactericidal and lysozyme activity of blood serum. However, at seven-month age there was marked a considerable decrease in number of erythrocytes, leukocytes, concentration of haemoglobin, bactericidal and lysozyme activity of blood serum is marked, in leukogram share reduction of segmented neutrophils, and at the same time, the content of eosinocytes and lymphocytes increased. It testified the decreasing of protective forces of an organism during this period. Consequently, the seventh month in the postnatal period of foal life proved to be the most critical.

Investigation of method of gastroenteritis treatment of stores by means of application of enterosorbents was realized in the conditions of the Republic of Belarus. For the experiment there was used preparation Lactofiltrum containing 80% of hydrolyzed lignin and 20% of lactulose applied in dose of 0,3 g/kg once a day during 7 days. Efficiency of application of Lactofiltrum was compared with enterosorbent SV-2, which contained alcaline hydrolyzed lignin applied in dose of 1 g/kg once a day during 7 days. Four experimental groups piglets sick with gastroenteritis in the age of 1,5-2 months, with body weight of 15-17 kg were used in the experiment. The first group piglets were entered 0,3 g/kg body mass of Lactofiltrum once a day during 7 days. The second group piglets were entered enterosorbent SV-2 in dose of 1 g/kg in course of 7 days. For the piglets of the third group there was applied the complex of analysed preparations in same course of treatment. The fourth group of piglets was entered enrotim 10% in dose of 1 ml/ 20 kg of body mass. All animals had the same conditions of feeding and keeping. Research results showed that application of Lactofiltrum, SV-2 and their complex provided high antioxidative, detoxification, gepathoprotective activities. These preparations proved to be effective means of pathogenetic therapy for the treatment of gastroenteritis of piglets, both as individual preparations, and complex application. Comparative estimation of treatment methods of gastroenteritis showed that these preparations (except enrotim 10%) made it possible to regulate the metabolic processes due to elimination of intoxication, positive influence on hematopoiesis. The preparations lowered the duration of clinic manifestation of a disease and facilitated its duration, had gepathoprotective and antioxidative activity

Data on working out a quantitative polymerase chain reaction (PCR) for revealing of virus of infectious bovine rhinotracheitis realized in the conditions of the Republic of Belarus was presented. The development of the qualitative PCR was realized in the following stages: analysis of viral genome and selection of primers; synthesis of primers and control of their specificity; optimization of conditions for PCR; obtaining of positive control and determination of its concentration; obtaining and testing of probe and optimization of its concentration for PCR; testing of the developed method and determination of sensitivity. The obtained method made it possible to determine not only presence of infectious bovine rhinotracheitis, but also its initial amount in sample. Due to application of probe constructed in accordance with molecular beacon technology the presented method proved to be highly specific. That was connected with the fact that fluorescence was registered only when the probe connected to complementary part of DNA, in other case the result was negative. Research results showed that the sensitivity of the given procedure made it possible to define in a sample presence of a virus with concentration 2 lg that corresponded to 2 DNA copies