. 2009 Jul 28;4(7):e6403. doi: 10.1371/journal.pone.0006403

Table 2. Fixed effects risk factors in the final models of soil properties at broiler grow-out farm location associated with probabilities of detecting Salmonella in the samples and drags swabs of litter (n = 76)^a.

Outcome/risk factor	Response	Mean (range) or count of sampled houses	Increment modelled	OR (95% CI) for increment or to reference category	p-value
Litter samples outcome
Total available water capacity	cm	25.85 (19.88–32.05)	1 cm	0.56 (0.43, 0.75)	0.0002
Moist bulk density	g/cm³	1.48 (1.34–1.58)	0.10 g/cm³	3.83 (1.03, 14.22)	0.0454
Latest month annual flooding can start in a normal year	Jan	60		9.42 (1.03, 86.33)	0.0473
	Nov/Dec	16		Reference
Drag swabs of litter outcome
Tolerance to erosion T-factor	Tonne	4.00 (3.00–5.00)	1.00 tonne	0.05 (0.01, 0.28)	0.0012
Rock fragments greater than 7.6–25.4 cm in diameter	% by weight of soil	0.37 (0.00–1.95)	0.25%	1.06 (1.01, 1.11)	0.0256
Natural drainage rate class^b	Ordered class	3 (1–5)	1 class	0.13 (0.04, 0.42)	0.0012

Random effects of the broiler farms, complexes, companies, or farm latitude were not found to make significant (p≤0.050) contributions to the variability in the responses in these models.

Soil natural drainage rate classes: Somewhat Excessive (15.2–50.8 cm per hour)–5, Well (5.1–15.2 cm per hour)–4, Moderately Well (1.5–5.1 cm per hour)–3, Somewhat Poor (0.5–1.5 cm per hour)–2, and Poor (0.2–0.5 cm per hour)–1.

Table 2. Fixed effects risk factors in the final models of soil properties at broiler grow-out farm location associated with probabilities of detecting Salmonella in the samples and drags swabs of litter (n = 76)a.

Table 2. Fixed effects risk factors in the final models of soil properties at broiler grow-out farm location associated with probabilities of detecting Salmonella in the samples and drags swabs of litter (n = 76)^a.