Investigation of acute and subchronic (chronic) toxicity of complexinates of trace elements in experiments with calves was realized in the conditions of the Republic of Belarus. The realized experiments were based on developed in Belarus veterinary preparations for the treatment and prevention of diseases connected with disorders of trace elements exchange containing chelate compounds of trace elements with sodium ethylene diamine acetate: Cuprovet (on the basis of CuNa); Cobalvet (on the basis of CoNa), Zinkovet (on the basis of ZnNa), and Feravet (on the basis of FeNa). There were the following indexes of ferrum in nephros - 55,3 +/- 2,26, in muscles - 134 +/- 26,6 mkg/g, and in liver - 565 +/- 35,5 mkg/g after administration of Feravet. There were the following index of zinc in nephros - 56,3 +/- 2,64, in muscles -25, 8 +/- 1,23 and in liver - 84,4 +/- 3,29 mkg/g after administration of Zinkovet. There were the following indexes of cuprum in nephros - 4,1 +/- 0,325, in muscles - 2,33 +/- 0,117, and in liver - 12,3 +/- 1,12 mkg/g after administration of Cuprovet. There were the following indexes of cobalt in nephros - 40,35 +/- 2,29, in muscles - 12,5 +/- 0,98, and in liver - 126,5 +/- 10,45 ng/g after administration of Cobalvet. Parameters of toxicity of all preparations were by the example of laboratory mice, rats and calves given. Content of trace elements in blood of calves in dynamics of the experiment was analyzed. There were determined parameters of acute toxicity of the analyzed preparations: they all could be referred to substance hazard category 4 (low-hazardous substances). The determined parameters of acute toxicity made it possible to recommend them for treatment and prophylaxis of microelementoses of cattle, as well as to use them as feed additives taking into consideration that defect action levels of the analysed preparations exceed the deficiency needs of cattle in case of their limited cumulation

Evaluation of pathogenicity of Paenibacillus alvei culture obtained from a dead bee brood from Berezinsky Biosphere Nature Reserve was realized in the conditions of the Republic of Belarus by an example of 30-day old white male mice with body weight of 16-18 grams. Experimental animals were infected with European foul brood (Paenibacillus alvei) intraperitoneally. Research results showed that bacteria Paenibacillus alvei after the intraperitoneal infection with various amount of microbial cells did not cause mouse death; i.e. it was not pathogenic for white mice. In course of the realized observations over the laboratory mice after introduction of infection there were stated no changes in mice behavior and overall condition. There were no visible pathologicoanatomic changes in internal organs. After the bacteriologic examination of internal organs and blood there were isolated pure cultures of Paenibacillus alvei

Investigation of histological structures of liver of fattening broiler chickens after application of concentrate of E and F vitamins produced on the basis of rapeseed oil was realized in the conditions of the Republic of Belarus in order to evaluate their efficiency for prophylaxis of massive hepatic necrosis. Research results showed that application of the vitamins on the basis of rapeseed oil promoted the support of structural properties of hepatic cells that proved their higher antioxidant efficiency in comparison with synthetic vitamin analogues

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)

Investigation of frequency of occurrence and manifestations of liver pathology of swine during the postmortem examination at meat packing plant of the Republic of Belarus was realized. Data analysis of reports of postmortem veterinary-sanitary examination gathered from two leasing national meat packing plants showed that out of 236187 of evaluated swine carcasses and organs in 40860 (17,3%) of cases there were registered different liver pathologies. Among the total number of liver pathologies in 5721 cases (14%) there were stated liver pathologies caused by invasive diseases (echinococcus disease (Echinococcus granulosus) – 1,5%; cysticercosis – 0,2%; migration traces of ascarid larva - 12,3%), and 31830 cases (86%) were caused by noncontagious diseases. The highest percentage among noncontagious liver diseases was stated for dystrophic organ changes (83,6%); the other 17,2% were caused by fibroid induration. During the morphological liver analysis there were stated the dystrophic and necrotic changes in fractions with the profound disturbance of blood circulation. At the same there was noted the disturbance of the whole fraction stricture, acute capillary engorgement in the central and peripheral zones

In the conditions of the Republic of Belarus after fasciolosis invasion of cattle for the biochemical diagnostics of liver pathologies there was composed a hepatospecific metabolic profile of blood serum of cattle into which there were included several enzymes (alanine aminotransferase; aspartate aminotransferase; gamma-glutamyl transpeptidase; alkaline phosphatase; and cholinesterase), content of total albumin, serum albumin, total cholesterin and total bilirubin, as well as colloid tests (thymol turbidity test and test for apoliproteins). There was revealed a intrahepatic cholestasis developed during fasciolosis infestation, as well as dysproteinemia as a compensatory mechanism of liver proteinsyntetic function.