Fig. 4.

Occurrence of Campylobacter spp. in different samples of the selected duck farms in relation to the variable management practices. A Variation in the overall occurrence of Campylobacter spp. under various categories of farm management practices. B–G Influences of each of the potential driving factors on the occurrence of Campylobacter spp. in different sample types. CS, ES, S, and DW indicate the types of samples, i.e., cloacal swab, egg surface swab, the soil of the duck resting places, and drinking water, respectively. The filled and unfilled portions in the stacked bars of each column represent the number of samples (n) detected positive and negative, respectively, for the occurrence of Campylobacter spp. A Chi-square test was performed to determine the significant association between Campylobacter occurrence and each of the driving factors. ***, **, *, and # indicate p values of < 0.0005, < 0.005, < 0.05, and < 0.1, respectively. Details of statistical information are included in Additional file 6