LAUSR

Introduction. On the territory of the North Caucasus Federal District, the most popular duck breeds at farm enterprises are Temp and Chernaya Belogrudnaya. They are fast growing, resistant to diseases and cold. Tetramerosis is a seasonal helminthic disease of ducks. At the same time, the epizootological features of tetramerosis infestation in domestic ducks are poorly studied from both fundamental and applied sides of the problem.The aim of the study was to investigate the tetramerosis infestation epizootological features and occurrence in the populations of domestic ducks of zoned breeds in the North Caucasus region (in the conditions of the Kabardino-Balkarian Republic).Materials and methods. Conventional methods of parasitological studies were used in the work: the method of complete helminthological dissection (СHD), determination of the infestation intensity and extensity. The results were statistically processed using the “Biometrics” software.Results. Tetramerosis infestation extensity (IE) in ducks of the breeds Temp and Chernaya Belogrudnaya in the context of natural areas of climatic zones of the Kabardino-Balkarian Republic (according to the data of the СHD of ducks glandular stomach and fundus glands) is manifested with different quantitative values covering most of the free-range growing birds of both breeds aged from 1 up to 6 months old. In the context of all natural and climatic zones, the extensity of tetramerosis infestation in ducks of the Chernaya Belogrudnaya breed was relatively higher than that of the Temp breed by 10.67 % in average. The activeness of the tetramerosis enzootic manifestation in ducks of the Temp breed: in the plain belt IE — 20.0 %; in the foothills — 30.0 %; in the mountain belt — 16.0 %. The average tetramerosis IE in ducks of the Temp breed was 22.00 ± 1.36 %. The tetramerosis infestation extensity in ducks of the Chernaya Belogrudnaya breed was: in the plain belt — 32.0 %; in the foothills — 42.0 %; in the mountain belt — 24.0 %. The average tetramerosis IE in the ducks of the Chernaya Belogrudnaya breed was 32.67 ± 1.83 %, which indicates a greater susceptibility to infestation. Upon the analysis of the glandular stomach and fundus glands dissection results of domestic ducks of the Temp and the Chernaya Belogrudnaya breeds in the natural and climatic zones of the Kabardino-Balkarian Republic it was also found that this infestation is manifested with extremely high rates of infestation intensity (II). Tetramerosis in domestic ducks of the Temp breed: in the plain belt was recorded with II — 18.3 ± 1.28 eggs/specimen; in the foothills — 25.7 ± 1.40 eggs/specimen; in the mountain belt — 15.9 ± 1.13 eggs/specimen. The average tetramerosis II in domestic ducks of the Temp breed was 19.97 ± 1.27 eggs/specimen. In domestic ducks of the Chernaya Belogrudnaya breed, the tetramerosis occured: in the plain belt with II 26.8 ± 1.73 eggs/ specimen; in the foothills — 33.4 ± 1.95 eggs/specimen; in the mountain belt — 21.2 ± 1.58 eggs/specimen. The average tetramerosis II in ducks of the Chernaya Belogrudnaya breed was 27.1 eggs/specimen.Discussion and conclusions. The rates of tetramerosis extensity and intensity in the ducks of the Chernaya Belogrudnaya breed tended to increase in domestic ducks of the age 1 to 6 months old. In subsequent age groups, the infestation was decreasing, which should be taken into account when determining the timing and frequency of dehelmintization.