Campylobacter species and AMR profiles at the two farms. Isolates were from cecal contents of birds from (A) TAU and (B) SIB. Species and AMR profile determinations were as described in Materials and Methods. Findings are shown for brooders (from onset of colonization in week 2 or 3 to week 5), grow-out birds (weeks 6 to 9), and total duration of the study (from onset of colonization to week 9) for each farm. CJ and CC in the color code inset indicate C. jejuni and C. coli, respectively. AMR profile acronyms indicate resistance to tetracycline (T), streptomycin (S), kanamycin (K), erythromycin (E), the quinolones nalidixic acid and ciprofloxacin (Q), and gentamicin (G); combination of letters indicates specific AMR profile, e.g., T, resistance only to tetracycline; TQ, resistance to tetracycline and quinolones; TSEKQG, resistance to all tested antimicrobials listed above; TSKQG, resistance to all tested antimicrobials listed above except for erythromycin.