The article describes a study on the antioxidant activity (AOA) of blood plasma of sheep in a pro-biogeochemical prov-
ince Republic of Belarus in relation to the content of trace elements in the blood and the age aspect, and also depending on 
the treatment and prevention. The relevance of this topic due to widespread of chronic endemic microelementoses among 
farm animals in Belarus. Sheep in Belarus until recently, exactly how and research in the field of internal diseases of sheep 
due to the peculiarities of biogeochemical province of the Republic of Belarus has not received proper development and re-
search on the subject are missing. 
AOA blood plasma of sheep in different regions of the biogeochemical province of the pro-Republic of Belarus has been 
studied by conducting monitoring studies in 2011-2014. Determination of micro-elements: zinc, cobalt, copper, manganese, 
cadmium and lead in whole blood was performed on the atomic absorption spectrometer MGA-915 (Russia). Selenium and 
iron were determined in serum selenium fluorimetrically 2.3-diaminonaphthalene and iron - with Feren without deproteiniza-
tion on automatic biochemical production with sets Cormey (Poland). 
Sheep in Belarus found subclinical metabolic trace elements in 61,2 % of cases. Among them: gipokobaltoz installed - at 60,6 % of 
the animals; Selenium deficiency - at 52,9 %; gipokuproz - at 44,9 %; Zinc deficiency - at 30,1 %; Manganese deficiency - at 9,2 %; iron 
deficiency - at 5,3 %, giperferoemiya - at 22,5 %, giperkuproemiya - at 9,3 %; gipermargantsemiya - at 4,3 %. 
It was found that the antioxidant activity of blood plasma in sheep as a whole and by age is largely correlated with the 
content of the studied trace elements in the blood and confirmed by correlation analysis. Significant positive correlation was 
found between the content of selenium and zinc on the one hand and plasma AOA other, sheep, both in general and in the age 
aspect.  Activity  AOA  plasma  (l  ·  mL-1  ·  min-1)  in  sheep  at  the  normative  content  of  zinc  was  1,765  ±  0,154,  when  gi-
potsinkemii - 1,38 ± 0,206; Significant differences were found in calves and sheep 1-2 years of age, respectively, in groups at 
gipotsinkemiya - 1,31 ± 0,112 and 1,35 ± 0,154, and at its normative content - 1,68 ± 0,122 and 1,71 ± 0,132. 
The imbalance of trace elements in the body of sheep of all ages and conditions specific to the Belarusian biogeochemi-
cal province microelementoses lead to a breach of prooxidant-antioxidant balance in animals manifested decrease AOA of 
plasma in animals. 
The article also shows the dynamics of plasma antioxidant activity in sheep in the application of different preparations of 
trace elements for preventive purposes. It has been found that the correction of unbalance by trace micronutrient enrichment 
rations leads to increase AOA plasma. In an experiment with animals diets enriched in trace elements it found that AOA 
blood plasma in animals asked inorganic salts of trace elements, was observed two week period AOA reducing blood plasma. 
Thus, in the beginning of the experiment AOA plasma in the experimental animals was 1,59 ± 0,115 L · mL-1 · min-1 on day 5 
in the test group, 1,49 ± 0,122, while in the control 0,118 ± 0,147 (p ≤ 0.05 ), and by day 14, these values respectively were 
1,65 ± 0,149 and 1,85 ± 1,29. On day 30 of the experiment AOA blood plasma in the test group was already higher than the 

control, and was for the groups respectively: 1,90 ± 0.180 1,66 ± 0,154 and l · · 1 ml min-1. In the experimental group, 
wherein use of complex corresponding microelements dynamics AOA blood plasma of animals were generally similar, how-
ever, such a noticeable reduction in its beginning of the experiment was found. So on day 5 of the experiment in the experi-
mental group AOA blood plasma in animals was 1,66 ± 0,155, and on day 14 - 1,80 ± 0,173 on the 30th day – 2,09 ± 0,15 L · 
mL-1 · min-1. Further, the trend of higher antioxidant activity in animal experimental groups was maintained throughout the 
experiment and after the 3-month period of application of the group which used complexonates it amounted to 1,92 ± 0,167 L 
· mL-1 · min-1, the second experimental group - 1,86 ± 1,48 and 1,58 ± 0,173 control. Thus, enrichment rations and removal of 
trace elements in animal microelementoses AOA accompanied by an increase of blood plasma in animals. Which once again 
confirms the fact that the violation of prooxidant-antioxidant balance in the body is the pathogenesis of polimikroelementoza, 
is typical of the sheep in the conditions of the Belarusian biogeochemical province. 
In appointing the animal therapeutic and prophylactic preparations of trace elements should be kept in mind some side 
effects associated with the reduction AOA blood plasma during the first 2 weeks. At the same time, side effects from drugs 
containing a trace natriyetilendiamintetratsetat not expressed. 
Key words: sheep, minerals, antioxidant activity of blood plasma, natriydiamintetraatsetat micronutrients.