Difference of <i>Chlamydiaceae</i> prevalence in farms with antibiotic group treatment between the first and second sampling.

a) pro-/metaphylactic group treatment after 1st sampling, type of antimicrobial substance: A = amoxicillin; C = chlortetracycline; CST = chlortetracycline, sulfadimidin, tylosin; TSS = trimethoprime, sulfadimidin, sulfathiazole; 1st = sampling at the beginning of the fattening period; 2nd = sampling at the end of the fattening period § = significant difference between the individual farms. Difference of Chlamydiaceae prevalence in farms with antibiotic group treatment between the first and second sampling.