Table 2.
Final multivariable model* of the associations between use of vaccines and consumption of antimicrobials with gastro-intestinal indications (AC-GI) in 1415 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-GI (ADD/100 weaners/day) | Converted AC-GI (ADD/100 weaners/day) | ||||
|---|---|---|---|---|---|---|
| Estimate of square root-transformed outcome | Standard error | P-value | Mean estimate | Lower 95 % CI | Upper 95 % CI | |
| Intercept | 2.384 | 0.076 | <0.0001 | 5.7 | 5.0 | 6.4 |
| Combinations of vaccines | 0.2 | |||||
| Group 0: PCV2 = 0 & MYC = 0 & LAW = 0 (n = 351) | 0.000 | n.a. | 5.7 | n.a. | n.a. | |
| Group 1: PCV2 = 1 & MYC = 0 & LAW = 0 (n = 277) | 0.145 | 0.097 | 6.4 | 5.5 | 7.4 | |
| Group 2: PCV2 = 0 & MYC = 1 & LAW = 0 (n = 204) | −0.004 | 0.106 | 5.7 | 4.7 | 6.7 | |
| Group 3: PCV2 = 0 & MYC = 0 & LAW = 1 (n = 21) | 0.021 | 0.270 | 5.8 | 3.5 | 8.6 | |
| Group 4: PCV2 = 1 & MYC = 1 & LAW = 0 (n = 476) | 0.183 | 0.085 | 6.6 | 5.8 | 7.5 | |
| Group 5: PCV2 = 1 & MYC = 0 & LAW = 1 (n = 32) | 0.258 | 0.222 | 7.0 | 4.9 | 9.5 | |
| Group 6: PCV2 = 0 & MYC = 1 & LAW = 1 (n = 9) | 0.058 | 0.405 | 6.0 | 2.7 | 10.5 | |
| Group 7: PCV2 = 1 & MYC = 1 & LAW = 1 (n = 45) | −0.026 | 0.190 | 5.6 | 3.9 | 7.5 | |
| Herd size (number of weaners pen places) | 0.02 | |||||
| Small (n = 468)a | 0.000 | n.a. | 5.7 | n.a. | n.a. | |
| Medium (n = 585)a,b | 0.151 | 0.075 | 6.4 | 5.7 | 7.2 | |
| Large (n = 362)b | 0.227 | 0.085 | 6.8 | 6.0 | 7.7 | |
n.a. not applicable, PCV2 Porcine Circovirus Type 2, MYC Mycoplasma hyopneumoniae, LAW Lawsonia intracellularis
a, b – different letters indicate variable classes with significantly different parameter estimates of antimicrobial consumption according to an F-test
*Model statistics: R 2 = 0.006, F = 2.0, P = 0.03