Table 3

Percentage and number (in parentheses) of piglets with a M. hyopneumoniae nested-PCR-positive laryngeal swab

Herd A
Age (weeks)abcdP valuea–c (NV)b–d (V)P* value
Weaning 325.4 (15/59)14.9 (10/67)14.7 (9/61)13.3 (8/60)0.27720.0 (24/120)14.2 (18/127)0.225
Nursery period 412.5 (7/56)0.0 (0/66)1.7 (1/59)1.8 (1/57)0.0887.0 (8/115)A 0.8 (1/123)B 0.039
Herd B
Age (weeks)abcdP valuea–c (NV)b–d (V)P* value
Weaning 40.0 (0/65)0.0 (0/57)1.6 (1/61)1.7 (1/58)0.9970.8 (1/126)0.9 (1/115)0.948
Nursery period 53.1 (2/64)1.8 (1/55)1.7 (1/58)1.8 (1/55)0.9432.5 (3/122)1.8 (2/110)0.738
  • 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).