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 studied sterility, harmlessness and immunoactivity of an obtained production vaccine against swine pasteurellosis by an example of laboratory animals – white mice and rabbits. Research results showed that the obtained vaccine was sterile and harmless for the laboratory animals, and had a high immunogenic activity. The analyzed vaccine prevented disease incidence of white mice after its double application in dose of 0,1 ml per animal and after a single immunization of mice in dose of 0,2 ml per animal. The inactivated vaccine caused the formation of immunity of rabbits after double immunization in dose of 1 ml per animal with 14 days interval and provided 100% vitality of animals.

The spectrum of acaricides changes continuously and improves. At the same time, big attention is given to research of new, more effective preparations meeting modern requirements. Research on studying the efficiency of Akaribil preparation against swine sarcoptosis (Sarcoptidae) was realized in the conditions of swine breeding farm in the Republic of Belarus. The preparation possesses high insect-acaricidal activity. In the conditions of the preparation storage and repeated opening of a ware in the course of tests there were stated no changes in drug smell or color. The scheme of the preparation application is applied in industrial production technology. It possesses anti-inflammatory properties, antiseptic stimulating healing of skin damages, does not irritate integuments, renders weak irritating effect on mucous membranes of eyes. In recommended doses Akaribil does not cause any adverse effects and complicating disease. There were stated no contraindications to preparation application. High therapeutic efficiency against arachnoentomosis was proved. Application the preparation made it possible not only to reduce disease incidence and animal death, but also to facilitate the severity of scabietic diseases. As a result of realized research it was established that efficiency of Akaribil against swine sarcoptosis was 100%.

In the conditions of the Republic of Belarus there were analyzed high productive traits of meaty calves and cross breeds bred in accordance with a system cow-calf, as well as the possibilities of using veal meat obtained in ecologically safe areas for infant food production. At the age of 6,5-7 months the weight of fresh carcass of bull-calves of sharolez breed in comparison with aberdin-angus х black-motley herdmates was on 41,6 kg (Р less than 0,001) higher, carcass yield and slaughter yield – on 13,8% (Р less than 0,001) and 13,6% (Р less than 0,001), respectively. The fat content in sharolez meat was 4,9% against 8,9%; protein - 21,9% against 18,8%. The black-motley suckling bull-calves surpassed their herdmates which were grown up by technology of dairy cattle breeding at the age of 6-6,5 months according to indexes of weight of fresh carcass - on 16,3 kg or 21,7% (Р less than 0,01); according to indexes in a slaughter yield - on 16,6% (Р less than 0,001); and according to indexes meat flesh in a carcass - on 1,5%. According to quality indexes, amino acid structure, acceptable concentration of toxic elements content, pesticides, antibiotics, radionuclides and other harmful substances the veal meat of calves which were bred on a system a cow-calve in ecologically pure zones proved to be important meat raw materials to produce infant food products.

In the conditions of the Republic of Belarus there were studied the aetiology factors in development of dermatoses of productive cows taking into account the hygienic aspects. Structural defects of floors of cattle livestock buildings in animals of an experimental group promoted higher (on 35%) development of mattery dermhelminthiasis of distal areas of hindlegs in comparison with animals of a control group. Occurrence of skin dermhelminthiasis, especially in distal areas of hindlegs, was caused by various primary traumas of soft parts with the subsequent introduction into them of pathogenic microbial flora. The imperfect design of floors, an unsatisfactory microclimate in cow cattle houses, hypodynamia in the absence of constitutional walk made the preconditions for it. The reasons of purulent dermatosis of cows were two interconnected etiological factors: mechanical damages of tissues and development of a surgical infections in affected areas against the background of unsatisfactory microclimate that led to decrease in dairy efficiency on 4,51%. Therefore in a complex of the actions directed towards the preventive maintenance of surgical diseases, it is necessary to include the strict control over designing, building and operation of cattle-breeding premises, traumatism prevention, creation of an optimum microclimate and observance of zoohygienic norms of cattle maintenance.

In the conditions of the Republic of Belarus taking into consideration the hygienic aspects there were studied the aetiological factors in dermatosis development in productive cows. As a result of realized research it was established that aetiology of skin diseases in the area of a mammary gland were traumas, and following affects were more often marked: skin rhagades of mammillars; wound in the area of a mammary gland and mammillars; fistulas of milk tank vessels; and also sporadic damages of sphincter muscle of teat canal caused by machine milking. This in its turn gives made it possible to consider, that traumas of various character were a contributing factor for occurrence of udder garget - mastitis. In course of the realized analysis there was proved a high therapeutic efficiency of 1% aethonium gel for the treatment of various traumas of mammary gland and udder mammillars of cows. Clinical recovery of animals after administration 1% aethonium gel was stated on 3,2 days earlier, than after administration of Burenushka cream in the postoperative period. Healing and restoring action of 1% aethonium gel for udder tissues was proved by changes in number of somatic cells in milk. The quantity of somatic cells in 7 days after administration of 1% aethonium gel came back to the level which was typical healthy animals, while in the control group the quantity of somatic cells per 1 ml of milk did not decrease essentially.

In the conditions of the Republic of Belarus there were studied biochemical indexes of calf blood serum against the background of application of probiotic preparations Bilavet C. Results of research showed that administration of probiotic preparations from the first day till the six day and from the fourteenth day till the nineteenth day of calf life with the preventive purpose rendered the simulative influence on indexes of natural resistance, which were accompanied with the increasing of total protein quantity in blood on 2,9-5,9%, as well as the increasing of protein fractions, in particular, globulin-rich fraction on 4,2-6,4%. Administration of probiotic preparation Bilavet С to calves rendered the positive influence on blood biochemical indexes, promoted the uptaking and better accumulation of mineral substances: content of crude calcium, inorganic phosphorus, magnesium, iron increased on 15,3%, 10,5%, 13,2% and 3,6%, respectively.

In the conditions of the Republic of Belarus there were studied circadian rhythms of some haemotological and biochemical blood indexes of clinically healthy calves and calves with a respiratory syndrome. There was analyzed the efficiency of administration a new complex mineral preparation CMP for correction of internal desynchronoses in complex therapy of calves with respiratory pathologies. Diseases of calves with a respiratory syndrome were accompanied by infringements of circadian fluctuations rhythm (internal desynchronosis) of haemotological and biochemical blood indexes. Application of an antimicrobial preparation Ampicillin for treatment of respiratory diseases of calves promoted the recovery of calves. Introduction of CМP preparation into therapeutic regimen of calves with respiratory syndrome proved to be rather effective; it promoted the correction of metabolic desynchronoses which accompanied the basic disease. Combined application of CМP and Ampicillin made it possible to speed up the clinical recovery of calves and on 30% to prevent animal mortality.

In the conditions of the Republic of Belarus there was studied a comparative efficacy of methods of drug administration for diseased animals with respiratory diseases. It was stated that enteral (internal) administration of Tromexin in a complex therapy of calves with respiratory pathology possesses rendered low therapeutic efficacy and could have a lethal outcome. Parenteral (intramuscular) administration of Enrotil and Dexafort for a complex therapy of calves with respiratory pathology rendered a moderate therapeutic efficacy and could lead to animal's state improvement. Parenteral (intravenous) administration of hypertonic solutions of norsulfazol, calcium chloride, sodium chloride and glucose in complex therapy of calves diseased with a respiratory pathology proved to render a high therapeutic efficacy and may lead in a complete clinical recovery.

In the conditions of the Republic of Belarus there were determined types of transferrins of 46-day old broiler chickens and their relation with indexes characterizing ferrum transport fund. In broilers of Smena-2 cross there were stated four transferrin phenotypes, which revealed at a electrophoregram in a form of two fractions with various mobility and intensity. The quantity of the found out phenotypes should be considered as a minimum one because it was possible to find out the infrequent forms only after realization of a very big number of research studies (for example, occurrence of some phenotypes can be 1:1000 and even lower). Perfection of electrophoresis techniques or application of other carriers (for example, polyacrylamide gel) can also increase a number of phenotypes owing to high resolving power and division of homogeneous transferrin fraction into several sub-factions. The type of transferrin actually did not render influence on the content of haemin proteins, while the indices of ferrum transport fund showed out such kind of dependence. Taking into account that total iron binding capacity (TIBC) was caused by transferrin presence in blood serum, the distinction in this indicator characterized both the transferrin content, and its transport possibilities in relation to iron. The highest content of total iron and TIBC was observed at a slow phenotype of CD tranferrin type (formed by fractions with the least mobility). Fast type of tranferrin АВ (formed by the most mobile fractions) had high enough content of the totaliron but possessed the least iron-binding ability that specifies to the worst performance capabilities of transportation of iron ions. Taking into consideration the transferrin value in formation of antibacterial immunity, it is possible to assume, that broilers with phenotype СD should be more resistant to infections.