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
| Variables and classes | AC-TOTAL (ADD/100 weaners/day) | Converted AC-TOTAL (ADD/100 weaners/day) | ||||
|---|---|---|---|---|---|---|
| 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 | |
n.a. not applicable, PCV2 Porcine Circovirus Type 2, MYC Mycoplasma hyopneumoniae, LAW Lawsonia intracellularis
a, b, c, d – different letters indicate variable classes with significantly different parameter estimates of antimicrobial consumption according to an F-test
*Model statistics: R 2 = 0.07, F = 12.2, P < 0.001