Determination of the influence of new premixes on sperm quality and natural resistance of sire bulls during winter and summer periods was realized in the conditions of the republic of Belarus. Application of the developed vitamin and mineral additive in rations of sire bulls in course of winter and summer periods made it possible to increase their natural resistance, that was proved by the 7,2-8,8% increasing of the bactericidal activity of blood serum indicators, 0,6% increasing of lysozymic activity of blood serum, and 3,3-5,1% increasing of the phagocytic ability of leukocytes. There was determined the possibility to increase sire bull sperm quality during different year periods by means of application of the enhanced doses of vitamins and trace elements. As a result, the ejaculate volume increased on 7,4-2,4%, concentration of male germ cells in ejaculate on - 6,3-7,8%, sperm activity - on 6,7-7,3%, and also there was stated the decrease of spoilage percent of sperm production. Results of the industrial testing have confirmed efficiency of use of the recommended vitamin and mineral additive and calculated on its basis premixes. Its application made it possible to increase the quality of bull of sperm production on 3,6-10,8%

In the conditions of biogeochemical zone of the Republic of Belarus the most important role in mineral metabolism is played by such major mineral elements as calcium, magnesium, phosphorus, potassium and trace elements - cobalt, cupper, iron, iodine, zinc, manganese, and selenium. Based on the above there was determined the interrelation between the content of these minerals in fodder and blood of milking and dry pregnant cows. As a result of realized study it was found out that the content of major mineral elements and trace elements in fodder did not always correspond to their level in blood. In the conditions of insufficient supply of Ca, F, Mg, K, Fe, Си and Co in cow diets, the level of potassium in blood was lower standard and the other analysed minerals were within the standard limits. There was stated the direct correlation relationship between the level of some biochemical indices and content of mineral substances in cow diets. Positive correlation was stated between the content of calcium and magnesium and cholesterin level in blood

Development of new selenium preparations in a complex with vitamins for the purpose of decrease of trace element toxicity and increase of its bioavailability is the topical problem of veterinary science. A new antioxidant water-soluble complex Aesel, which includes selenium as the activated product of interaction of methionine and sodium selenite, vitamins A and E, is researched. Lethal doses of the preparation for mice and rats were identified through intragastric and subcutaneous introduction. Due to the results of the research it was determined that Aesel is rated among the forth class of danger, so it is dangerous to a very little degree. Lethal doses of the preparation on the pure selenium, calculated on Pershin method, for rats at parenteral introduction is equal 5,48, at enteral introduction - 39, for mice at parenteral introduction - 7,72 mg/kg. Lethal doses of the preparation calculated on all making components equal to 39000 mg/kg.

There were studied the veterinary-sanitary indicators of sheep slaughter products in the conditions of application of microcelements in various forms. Studying of the influence chelate forms of microelements on quality of cattle-breeding production is spent in comparison with preparations in which microelements are in a kind of salts. As a model preparation, for studying of chelate influence on quality of cattle-breeding production used of the chelate zinc form - Tsinkovet. Results of research show, that use of chelate and inorganic forms of zinc does not reduce high quality of received production. Meat of sheep of trial groups on organoleptic, bacteriological and physical and chemical indicators, and also biological value and harmlessness is characterized as good-quality and corresponds to veterinary-sanitary requirements. In tables results of physical and chemical researchs of meat, its biological value and harmlessness are presented. | Целью исследований явилось изучение ветеринарно-санитарных показателей продуктов убоя овец при назначении им микроэлементов в различных формах. Изучение влияния хелатных форм микроэлементов на качество животноводческой продукции проведено в сравнении с препаратами, в которых микроэлементы находятся в виде солей. В качестве модельного препарата, для изучения влияния хелатов на качество животноводческой продукции использовали хелатную форму цинка - Цинковет. Результаты исследований показывают, что использование хелатных и неорганических форм цинка не снижает доброкачественности получаемой продукции. Мясо овец опытных групп по органолептическим, бактериологическим и физико-химическим показателям, а также биологической ценности и безвредности характеризуется как доброкачественное и соответствует ветеринарно-санитарным требованиям. В таблицах представлены результаты физико-химических исследований мяса, его биологическая ценность и безвредность.

Belarus is among regions, where the selenium content in soil, hence, in cereal and other cultures considerably below requirements that leads to insufficiency of this microelements in a diet as the person, and animals. Synthesized in the All-Russian Scientific Research Institute of Physiology, Biochemistry and Feeding of Agricultural Animals new organic compound of selenium - selenopyran on variety of criteria has no analogues in the world among considerable quantity selenium of containing preparations and favourably differs from all known forms of microelements. Selenopyran, brought in fats and forages, shows antioxidatic the properties which are not conceding traditionally applied in veterinary science and medicine to antioxidants. Arriving in animal body with forage or in the form of injections, selenopyran is capable to play a role of a metabolic regulator. It activates enzymes of antioxidatic body protection, reduces formation new and will neutralize of earlier formed activeproducts of peroxide lipids oxidations, improves functioning of cellular membranes, normalizes metabolism, makes active cellular, humoral and phagocytal immunity links, raises nonspecific resistance and efficiency of animals. Toxicity of selenopyran more low, than at all known organic connections of selenium, and more than in 100 times is less, than at sodium selenit. The data allow to expand possibilities of application of organic selenium and to use it as a preparation raising resistance and body viability at the expense of the patronage of cellular structures from influence of oxidizers and free radicals, to normalize metabolism and to stimulate thus the big additional body weight at animals. The influence of medicine organic selenium on piglet bodies what are behind a growth and development is shown. The results showing the dynamical changes of haematologicals, physiologicals and biochemicals indices under the influence of selenopyran was given.