In the conditions of the Republic of Belarus there was studied a state of lipid peroxidation, antioxidant protection and activity of hepatospecific enzymes of blood plasma of piglets. Research results showed that weanling piglets which had low body weight in the conditions of industrial breeding technology were characterized by high intensity of processes of lipid peroxidation. At the same time, the antioxidant system reacted adequately to the mentioned above changes. There was noted a high dependence between the content of Schiff's bases which were the end-products of lipid peroxidation processes, and the activity display of amplifier hepatospecific enzymes of blood plasma of weanling piglets. The received results of research can be used for estimation of a condition of prooxidant and antioxidant status, and in a complex with data on activity of sorbitol dehydrogenases, isocitratdehydrogenases and glutamatedehydrogenases - for an estimation of a functional state of a liver of weanling piglets with low body weight at an initial stage of their breeding.

This article is devoted to a problem of biochemical interaction of selenium and antioxidational system of animals and people organism. The problem we have touched is about the efficiency of influence of organic and inorganic taking place on subcellular level. The advantages of organic selenium are proved, the degree of its bjochemical influence on an antioxidationi status of health are indicated.

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.