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

Analysis of synchronization of oestrus of cows by means of Ovsynch and Pre-Synch methods was realized in the conditions of the Republic of Belarus. Research results showed that estrus synchronization by means of Pre-Synch method proved to be more efficient by means of higher percentage of fertilization after the first and second insemination in comparison with Ovsynch method. Treatment of cows with the substances Surfagon and Tetravit for synchronization of oestrus did not render negative effect on milk quality and safety.

Results of studying the efficiency of iodine containing preparation Jodon which was applied to highly productive cows with hypovarianism and to servicing bulls in order to increase their reproductive function realized in the Republic of Belarus were presented. On the basis of realized studies there was proved the considerable efficiency of Jodon preparation.

Development of a new national preparation for the preventive maintenance of cow mastitis, fissures of milking tubes skin of cow udder was realized in the conditions of the Republic of Belarus. The preparation Maz' Solnechnaya ("Unguent Solnechnaya") did not contain antibiotics, hormones and other synthetic components. Natural components of a preparation provide long anti-inflammatory action, stimulate local blood circulation, regeneration of epidermis and accelerate processes of healing of microtraumas. Besides it possesses high efficiency at preventive maintenance of mastitises at cows.