Comparison of the antimicrobial consumption in weaning pigs in Danish sow herds with different vaccine purchase patterns during 2013

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)
Variables and 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

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

ISSN: 2055-5660