In the conditions of the Republic of Belarus there were determined the parameters of acute and subacute toxicological characteristics of the developed in the Vitebsk State Academy of Veterinary Medicine anthelmintic preparations of durable action Febolvetum-О for control of sheep strongylatosis and Febolvetum for control of strongylatosis of cattle young stock. Data on determination of toxicological parameters of the prolonged action bolus were presented. Research results showed that the preparations did not render negative influence on laboratory animals (white mice). According to the parameters of acute oral toxicity the Febolvetum was qualify as the third hazard class. In accordance with the results of study of subacute toxicity parameters of the preparations, it was concluded, that in the conditions of free feeding of Febolvetum boluse in combination with forages in course of 30 days in doses of 200 mg/kg; 150 mg/kg; 100 mg/kg of body weight in animals there were found no signs of intoxication; there were not stated any is not fixed deviations in physiological state; and were stated no mice death.

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 was studied the influence of various doses of dolomite on productivity, egg quality and a mineral metabolism of laying hens. The research was realized by an example of laying hens of Highsex Brown. The experimental hens at the age of 250 days old were divided into 4 groups on 60 heads in each by means of analog method. Laying hens of the first (control) group were fed with a basic diet including 5% of a soya cake (cockle-shell), and hens of the second, third and fourth (experimental) groups instead of a soya cake were fed with a mixed fodder with addition of a mineral additive of dolomite. Hens of the second group were fed with the additive at a rate of 2%, the third group - 3%, and the fourth group - at a rate of 5% of weight of dry matter of forage. During the experiments there were maintained optimum parameters of microclimate, recommended temperature and light regimes and a sufficient ultra-violet irradiation. As a result of the realized research it was established, that use of the mineral dolomite additive in feeding of laying hens proved to be possible as a substitute of an expensive import cockleshell. Use of various doses of dolomite promoted improvement of mineral metabolism, increasing of productivity and improvement of egg quality of laying hens.

In the conditions of the Republic of Belarus there was analyzed the efficiency of application of organic form of selenium Sel-plex in feeding of producer bulls. In course of the study there was showed the dynamics of live weight and average daily weight gain of producer bulls; blood indexes of analimals by the end of the experiment; sperm quality of experimental bulls. As a result of research it was established, that application of organic form of selenium Sel-plex in feeding of breeding bulls during the summer and winter periods in a dose of 0,4 mg/kg of dry matter of a ration promoted the increasing of daily average live weight gain on 6,4-8,1%, improvement of morphological and biochemical blood structure, increasing of indices of natural resistance on 0,5-6,1% and sperm production quality - on 7,3-28,0%.

In the conditions of the Republic of Belarus it was determined that application of monocalcium phosphate in a dose of 10 gram per 1 kilogram of mixed fodder and specified doses of trace elements (cuprum; zink; cobalt; manganese; iodine) in diets of growing pedigree bull calves made it possible to increase indices of body weight of young cattle stock of the third experimental group in comparison with animals of the first and the second groups on 18,3 and 11 kg or respectively on 3,9 and 2,3%; as well as to increase the intensity of their growth. The highest daily average live weight gain was noted at animals of the third experimental group – 1062 grams. It was higher than at bull calves of the first and the second groups respectively on 31,3 and 12,8 grams, or on 3 and 1,2%. Application of monocalcium phosphate in a dose of 10 gram per 1 kilogram of mixed fodder favorably affected the formation of desirable type of sexual behavior and indices of semen production quality. Thus, in the third experimental group in comparison with animals of the first and the second groups the volume of ejaculate was on 0,2 and 0,1 ml higher (or on 5,8 and 2,9%); quantity of sperm in ejaculate - on 0,7 and 0,3 billion, or on 35 and 15%.

In the conditions of the Republic of Belarus there was analyzed the productivity of 13-18-month old young stock of cattle which was bred for meat with various levels of energy value nutrition. Also, there were noted their slaughter qualities and chemical composition of meat. Administration of diet rations with an increased level of exchange energy and the best indices of protein fissility rendered a positive influence on productivity of young stock of fattening cattle and made it possible to obtain 1103-1100 gram of body weight gain. As a result, the energy value gain was 22,9-22,6 MJ along with conversion of metabolizable energy at a gain - 24,7-25,3%. Consumption of metabolizable energy per 1 MJ along with body weight gain were within 4,7-5,0 MJ. Feeding of rations with various levels of the studied factor rendered the positive influence on slaughter qualities, made it possible obtain slaughter yield of 53,6-54,6% at an optimum ratio of nutrients in meat. Feeding of bull calves with diets with excessive content (up to 10%) of metabolizable energy made it possible to lower the prime cost of obtained breeding products on 0,55%.

Study of sensitivity of Paenibacillus alvei to different antibiotic preparations (penicillin, tetracycline, neomycine, kanamycin, ampicillin, polymyxin, laevomycetin, enrofloxacin, tylosin, and streptomycin) was realized in the conditions of the Republic of Belarus. As the material of the research there was used the culture of agent the European foul brood caused by Paenibacillus alvei. Determination of therapeutic effectiveness of antibacterial agents in vitro conditions made it possible to choose the appropriate preparation for its use at beeyards with European foul brood caused by Paenibacillus alvei. During the experimental work there were used 10 antibacterial disks with various antibiotics. The best result against Paenibacillus alvei was shown by Tilozin, the diameter zone of growth inhibition was about 47,2+/-3,43 mm.

Sensitivity of European Faulbrut causative agent to Gentavet preparation was studied in the conditions liquid nutritive media in vitro in the Republic of Belarus. Research results showed that the studied preparation rendered the poisonous influence on European Faulbrut causative agent in concentration of 0,3 mkg/ml with the maximum rate 1:131072. The antibiotic showed the bacteriostatic ability in concentration of 0,15 mkg/ml. The antibacterial preparation did not influence the European Faulbrut causative agent in concentration of 0,01 mkg/ml. The total bacteriostatic effect the drug showed in concentration of 0,22 mkg/ml and its dilution of 1:196608.

Research on working out of a new fodder additive on the basis of rape (Brassica napus) phospholipids which included mineral substances necessary for normal functioning of cattle was realized in the conditions of the Republic of Belarus. Results of biochemical analysis of 35240 blood samples revealed that 15-40% of studied animals had abnormalties in vitamin, protein and mineral metabolism and lowering of immunobiological disease resistance. There was correlation dependence between the degree of metabolic orders and the state of forage reserve of a forage reserve. The lowering of forage reserve caused the increasing of metabolic disorders. As a whole forages of the surveyed farms were low in content of copper, zinc, cobalt and selenium and could not provide physiological requirements of animals without introduction into rations of specialized additives

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