Table 2.

Values (means ± SD) for true positive and true negative measurements displayed by commercial calves used in the present study

	Core temperature (°C)	White blood cells (×103 μL−1)	Clinical scorea	Neutrophil/lymphocyte ratio	Salivary cortisol (μmol/L)	IRTb (°C)
True positive n = 37	38.98 ± 0.27	9.04 ± 2.31	2.41 ± 1.36	0.40 ± 0.24	2.48 ± 1.93	37.49 ± 0.94
True negative n = 53	39.06 ± 0.29	7.86 ± 1.70	2.26 ± 1.19	0.35 ± 0.21	3.98 ± 2.61	37.29 ± 0.95
Probabilityc	0.41	0.01	0.60	0.87	0.004	0.34

Data are used for 4–6 days prior to illness in a subset of calves subsequently determined as true positive using the gold standard values.

^aPlease see methods section in text for description of clinical score system.

^bIRT = infrared thermography value for the orbital (eye) maximum temperature.

^cProbability determined by least squares analysis using Microsoft excel two tailed t-test.