Fig. 1

Comparison of the prevalence of M. hyopneumoniae between groups. a Comparison of detection rates by herd size: positive piglet prevalence in farms with > 550 sows (□) and others (■). b Comparison of detection rates by gilt replacement rate: prevalence of positive piglets in farms with > 40% replacement (□) and others (■). c Comparison of detection rates by gilt status: prevalence of positive piglets in farms introducing serologically positive (■) and negative gilts (□). d Comparison of detection rates by gilt source: prevalence of positive piglets in farms that produce their own replacement gilts (■) and farms that acquire their gilts from GP (□). e Comparison of detection rates by acclimation method: prevalence of positive piglets in farms that naturally expose gilts to M. hyopneumoniae (■), farms that vaccinate gilts (■), and farms that do not use acclimation treatment (□). f Comparison of detection rates by antibiotic usage for sows: prevalence of positive piglets in farms that use antibiotics on sows (■) and farms that do not use such treatment (□). g Comparison of detection rates by antibiotic use on piglets; positive piglet prevalence in farms that use antibiotics on piglets (■) and farms that do not use such treatment (□)