Prevalence of foot and mouth disease virus antibodies in an organized sheep farm of Rajasthan

In this study we estimated the seroprevalence of foot-and- mouth disease virus (FMDV) infection in an organized sheep farm at Arid Region Campus (Central Sheep and Wool Research Institute) Bikaner, Rajasthan. A total of 524 (175 Magra and 349 Marwari breed) serum samples from sheep (125 in February and 399 in August 2011) were collected and subjected to 3AB non-structural protein (NSP) ELISA. High and comparable percentages of NSP antibody prevalence 35.20% and 30.57% were found at both time points 6 months apart indicating an exposure of animals to FMD virus probably before the first sampling. The serum samples when tested in liquid phase blocking ELISA to assess the overall herd immunity (the level of structural protein antibody log₁₀ titre of ≥ 1.8 against FMDV serotypes Q, A and Asia 1 in the farm, itwas found to be 0% during first sampling and 29.32% at second sampling. Such poor herd immunity correlates with the practice of irregular vaccination that might have made the farm susceptible to FMDV exposure. Hence, routine FMD vaccination should be strictly followed in the farm to build up an optimum level of flock immunity against FMD.