In the conditions of the Republic of Belarus there was analyzed fauna of parasites of gastro-intestinal tract and natural resistance of horses in the conditions of Polesye State Radiation Ecological Reserve. There were worked the most efficient antihelminthic compounds. Analysis of helminthological state showed that extensiveness helminthic and gastrophilosis invasion of horses was at a high level. In this regard the nematodosis and gastrophilosis (Gastrophilus intestinalis) invasions prevailed. In mature and growing horses there was marked the dominance of nematode worms of Strongylidae / Trichonematidae families (78,9-83,8%) and Gasterophilidae (95,8%). Next, at growing horses there were stated nematodes Strongyloides westeri and cestoid worms of Anoplocephalidae family, at mature horses – of Gasterophilidae, Parascaris equorum and Oxyuris equi families. The following antihelminthic compounds ans preparations showed the best efficiency: Univerm; Avermektin paste 1%; Fenbendazoli, Rivertin 1%.

In the conditions of the Republic of Belarus there was studied the formation of nonspecific protection factors of the first year foals. By a principle of conditional analogues there was generated a group of clinically healthy foals at which monthly from bulbar veins there were taken tests of blood for hematological and biochemical analysis. From the obtained data it was visible, that within the first year of foal life there were taking place the processes of formation of nonspecific protection factors of an organism which were accompanied by a gradual increasing of quantity of erythrocytes, haemoglobin, leukocytes, certain change in the diagramme, and also increasing of bactericidal and lysozyme activity of blood serum. However, at seven-month age there was marked a considerable decrease in number of erythrocytes, leukocytes, concentration of haemoglobin, bactericidal and lysozyme activity of blood serum is marked, in leukogram share reduction of segmented neutrophils, and at the same time, the content of eosinocytes and lymphocytes increased. It testified the decreasing of protective forces of an organism during this period. Consequently, the seventh month in the postnatal period of foal life proved to be the most critical.

The Republican Agricultural Breeding Unitary Enterprise Zarechje of the Republic of Belarus is the basic horse-breeding enterprise of Belarusian coach horse breeding. In the enterprise there are 27 mares and 2 studhorses; all animals are purebred. It is established, that unaltered male horses and mares belong to Belarus coaching breed, all pedigree animals have a high class: 15 horses belong to an elite class that makes 75% from all herd, 4 heads concern the first class (20%), and 1 head – to the second class (5%). Measurements surpass the standard that can prove the appropriate selection and breeding work in the enterprise. After studying the measurements of studhorses of the enterprise in comparison with the standard it was established, that the height at crest of stallions on the average exceeds the breed standard on 30%, slanting length of a trunk - on 5,0%, a breast grasp - on 4,0% and a metacarpus grasp - on 6%. For improvement of herd of horses it is necessary to organize correctly a coupling campaign with drawing up of the coupling plan and selection of a uterus to stallions; to use in copulation only the best elite stallion.

In the conditions of the Republic of Belarus there was presented a characteristic of breeding stock of mares of Trakensky breed in accordance with body conformation and exterior. In course of the study there were taken measurements of height at the shoulder, heart-girth, metacarpus circumference at 1 year old and two year old age stages. There was calculated an index of massiveness which characterize the development of chest, index of bone which provided insight into skeleton development. Research results showed that in accordance with an exterior the breeding stock mares had a deep and massive barrel, good skeleton and developed muscle. The index of massivness was 118,4-120,5, bone index – 20,8-21,6, that corresponded to a type of riding horses. In accordance with the exterior, measurements and quality of posterity the mares of the bred lines obtained high grades and 93,5% were graded as elite class.