Occurrence of mycoplasma hyopneumoniae in coughing piglets (3-6 weeks of age) from 50 herds with a history of endemic respiratory disease

The objective of this study was to determine the occurrence of Mycoplasma hyopneumoniae in the lower respiratory tract of suckling and recently weaned pigs from herds with a history of endemic respiratory disease in this age group. Bronchoalveolar lavage fluid was obtained from 500 clinically affected piglets originating from 50 herds (10 piglets per herd). The presence of M. hyopneumoniae was examined by application of a nested polymerase chain reaction. Mycoplasama hyopneumoniae was detected in lavage fluid in 12.3% of the suckling piglets and 10.6% of the weaned piglets (mean 11.2%). The percentage of herds in which M. hyopneumoniae could not be detected was 72% and in two of the herds all samples were tested positive. Herd level information on relevant hygiene, housing and management factors was obtained by means of a structured questionnaire. The univariable data analysis (odds ratio) showed that the detection of M. hyopneumoniae in young piglets is associated with one- and two-site production and inappropriate gilt acclimatization. © 2009 Blackwell Verlag.