ESPHM 2026 - Case Report: Impact of Mass Sow Vaccination Against Mycoplasma hyopneumoniae on Piglet Colonization at Weaning

E. Bénéteau, M. Lesueur, J.-B. Herin, G. Mabecque

Background

This study was conducted in a commercial herd of 1,500 sows that had previously experienced a Porcine Respiratory Disease Complex (PRDC) outbreak. The objective was to assess whether vaccinating sows,following specific veterinary advice could reduce the transmission of Mycoplasma hyopneumoniae (M. hyo) to piglets. Historically, the farm received gilts from a source infected with M. hyo. However, for the past 18 months, gilts have been sourced from a multiplication farm free of M. hyo, which also supplies other farms that routinely practice mass vaccination of breeding animals against this pathogen. During a veterinary visit, it was discovered that sow vaccination had been discontinuedon this farm, creating an opportunity to compare outcomes between vaccinated and unvaccinated systems.

Material and Methods

The vaccination program used Ingelvac MycoFLEX® for both sows and piglets. Deep tracheal swabs were collected from piglets at weaning after reintroducing sow vaccination and compared with samples from other vaccinated herds supplied by the same multiplier. PCR testing was performed to detect the presence of M. hyo.

Results

All piglet samples from the farm following mass sow vaccination tested negative for M. hyo, as did samples from other vaccinated herds (Table1). Additionally, respiratory issues during the fattening phase were no longer observed. These findings confirm that sow vaccination efectively prevents piglet colonization at weaning, reducing the prevalence of PCR positive animals. As illustrated in Figure 1, the antibiotic treatments were also dramatically reduced after the arrival of the piglets born from revaccinated sows.

Conclusions

Mass vaccination of sows against M. hyo is a reliable strategy to limit pathogen transmission in modern swine production. By preventing early colonization,this approach improves respiratory health and lowers the risk of future outbreaks. The study also underscores the importance of compliance with veterinary recommendations and monitoring piglets at weaning to ensure disease control, even in the absence of clinical signs.

References

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