Sampling technique and Sample Size determination
Multistage sampling technique was employed to select study population by
taking ‘district’ as the first stage, ‘pastoral association’ as the
second stage, and ‘herd’ as the third stage. Study districts were
purposively selected based on higher study population, access to
transportation, history of outbreaks and willingness of pastoralists to
participate in this research work for seroprevalence determination and
assessment of potential risk factors of FMDV. Finally, individual animal
from each herd was selected randomly as secondary sampling unit to
attain the required sample size. Since there is no previous study
conducted on FMD in cattle found in the selected areas, the present
study has considered 50% expected prevalence, 95% confidence level and
5% absolute precision or marginal error. Based on these assumptions,
the total number of animals to be included in the study got determined
using Thrusfield (2007) formula.