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

Table 3 Final multivariable model* of the associations between use of vaccines and consumption of antimicrobials with respiratory indications (AC-RESP) in 836 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-RESP (ADD/100 weaners/day)			Converted AC-RESP (ADD/100 weaners/day)
Variables and classes	Estimate of log-transformed outcome	Standard error	P-value	Mean estimate	Lower 95 % CI	Upper 95 % CI
Intercept	0.497	0.145	<0.0001	1.6	1.2	2.2
Combinations of vaccines			<0.0001
Group 0: PCV2 = 0 & MYC = 0 & LAW = 0 (n = 155)^a,c	0.000	n.a.		1.6	n.a.	n.a.
Group 1: PCV2 = 1 & MYC = 0 & LAW = 0 (n = 136)^a	0.404	0.177		2.5	1.7	3.5
Group 2: PCV2 = 0 & MYC = 1 & LAW = 0 (n = 134)^b	0.648	0.177		3.1	2.2	4.4
Group 3: PCV2 = 0 & MYC = 0 & LAW = 1 (n = 10)^a,c	0.160	0.490		1.9	0.7	5.0
Group 4: PCV2 = 1 & MYC = 1 & LAW = 0 (n = 349)^b	0.672	0.146		3.2	2.4	4.3
Group 5: PCV2 = 1 & MYC = 0 & LAW = 1 (n = 13)^c	−0.994	0.434		0.6	0.3	1.4
Group 6: PCV2 = 0 & MYC = 1 & LAW = 1 (n = 6)^a,b,c	−0.166	0.626		1.4	0.4	4.7
Group 7: PCV2 = 1 & MYC = 1 & LAW = 1 (n = 33)^a,b,c	0.220	0.289		2.0	1.2	3.6
Herd size (number of weaners pen places)			0.06
Small (n = 235)	0.000	n.a.		1.6	n.a.	n.a.
Medium (n = 331)	−0.261	0.129		1.3	1.0	1.6
Large (n = 270)	−0.295	0.136		1.2	0.9	1.6

n.a. not applicable, PCV2 Porcine Circovirus Type 2, MYC Mycoplasma hyopneumoniae, LAW Lawsonia intracellularis
^{a, b, c} – different letters indicate variable classes with significantly different parameter estimates of antimicrobial consumption according to an F-test
*Model statistics: R ² = 0.04, F = 4.8, P = 0.001

ISSN: 2055-5660