# Table 1 Final multivariable model* of the associations between the use of vaccines and total consumption of antimicrobials (AC-TOTAL) measured as Animal Daily Doses (ADD) per 100 weaners per day in 1513 Danish sow herds after controlling for production size, 2013. Group 0 (no vaccination) and small herd size were used as reference classes

Estimate of square root-transformed outcome Standard error P-value Mean estimate Lower 95 % CI Upper 95 % CI
Intercept 2.573 0.0732 <0.0001 6.6 5.9 7.4
Combinations of vaccines    <0.0001
Group 0: PCV2 = 0 & MYC = 0 & LAW = 0 (n = 380)a 0.000 n.a.   6.6 n.a. n.a.
Group 1: PCV2 = 1 & MYC = 0 & LAW = 0 (n = 290)b,d 0.324 0.096   8.4 7.3 9.5
Group 2: PCV2 = 0 & MYC = 1 & LAW = 0 (n = 221)b,c,d 0.433 0.103   9.0 7.9 10.3
Group 3: PCV2 = 0 & MYC = 0 & LAW = 1 (n = 21)a,b,c,d 0.192 0.274   7.6 5.0 10.9
Group 4: PCV2 = 1 & MYC = 1 & LAW = 0 (n = 507)c,d 0.635 0.084   10.3 9.3 11.4
Group 5: PCV2 = 1 & MYC = 0 & LAW = 1 n = 35)a,d 0.083 0.216   7.1 5.0 9.5
Group 6: PCV2 = 0 & MYC = 1 & LAW = 1 (n = 11)a,b,c,d −0.118 0.374   6.0 3.0 10.2
Group 7: PCV2 = 1 & MYC = 1 & LAW = 1 (n = 48)a,b,c,d 0.202 0.188   7.7 5.8 9.9
Herd size (number of weaner pen places)    <0.0001
Small (n = 528)a 0.000 n.a.   6.6 n.a. n.a.
Medium (n = 607)b 0.264 0.073   8.0 7.3 8.9
Large (n = 378)c 0.459 0.083   9.2 8.2 10.2
1. n.a. not applicable, PCV2 Porcine Circovirus Type 2, MYC Mycoplasma hyopneumoniae, LAW Lawsonia intracellularis
2. a, b, c, d – different letters indicate variable classes with significantly different parameter estimates of antimicrobial consumption according to an F-test
3. *Model statistics: R 2 = 0.07, F = 12.2, P < 0.001 