Table 6

Percentage of pigs with Mycoplasma hyopneumoniae-like lung lesions (Mhyo) and fissures at slaughter, and lung lesion score (LLS; average ±SD)

Herd A
a (n=33)b (n=33)c (n=35)d (n=31)P valuea–c (NV; n=68)b–d (V; n=64)P* value
Prevalence of Mhyo-like lesions95.7A 65.2B 60.0B 47.6B 0.03877.1A 56.8B 0.045
Prevalence of fissures33.317.40.00.00.67616.39.10.360
LLS29.4±19.1A 14.9±16.7B 23.6±28.6AB 16.1±21.8B 0.03226.4±24.4A 15.5±19.1B 0.021
Herd B
a (n=47)b (n=55)cdP valuea–c (NV; n=47)b–d (V; n=55)P* value
Prevalence of Mhyo-like lesions78.774.1N/A†N/A†N/A†78.774.10.649
Prevalence of fissures46.837.9N/A†N/A†N/A†46.837.90.428
LLS8.4±8.59.7±11.6N/A†N/A†N/A†8.4±8.59.7±11.60.541
  • Vaccination status: NV (pigs originating from non-vaccinated sow farrowing batches) and V (pigs originating from vaccinated sow farrowing batches). The P value refers to the comparisons between the individual farrowing batches, and the P* value to the comparisons between the summaries of the NV (a–c) and V (b–d) batches. Values with different superscripts within a row are significantly different (P<0.05 and P*<0.05).

  • †Non-applicable as pigs of batches c and d were slaughtered before the pre-arranged time and thus, no lung lesion evaluation was performed.