Seasonal Nematodirus Infection in the Edilbaev Sheep in the Kulunda Steppe

The research purpose was to study seasonal characteristics of nematodirosis manifesting in the Edilbaev sheep introduced into the Kulunda Steppe of the Altai Region. Fecal samples collected from spontaneously infected animals were studied by coproovoscopic method per Fülleborn. The Nematodirus infection in sheep in different seasons of the year was characterized in view of incidence rates (prevalence, %) and infection intensity (average number of eggs per gram of feces (egg/g) per one studied and infected animal). A total of 240 fecal samples were examined. It was found that annual dynamics of the epizootic process was typical for Nematodirus. The minimum Nematodirus infection rate in sheep was recorded in July (prevalence = 10.0%) with an increase to 68.8% observed in August and maximum values of 95.6% recorded in October. Similar results were detected for the intensity of infectious process of nematodirosis, namely, the maximum number of eggs in fecal samples per examined and infected animal was recorded in autumn, 193.1 and 235.9 egg/g, accordingly, and the minimum in April, 2.0 and 20.6 egg/g, accordingly. The summer-autumn seasonal pattern of the infectious process of nematodirosis in sheep was due to the maximum contamination of land with helminth eggs during this period.