Table 1.

Spearman correlation coefficients¹ for body temperatures in heat-stressed feedlot lambs supplemented with ractopamine or zilpaterol for 18 d

	Temperature
		Corneal (IR camera2)		Ear (IR camera2)		Nose (IR camera2)		Shorn skin (IR guns3)	Unshorn skin (IR guns3)
Measurement	Rectal (Digital)	1 m	2 m	1 m	2 m	1 m	2 m
Ambient temperature	0.61	0.83	0.89	0.90	0.91	0.77	0.75	0.89	0.90
RH	0.51	0.73	0.70	0.77	0.76	0.65	0.62	0.72	0.71
THI	0.63	0.81	0.85	0.91	0.92	0.76	0.72	0.92	0.91
Rectal temperature		0.55	0.59	0.66	0.66	0.36	NS	0.71	0.65

¹Spearman correlation coefficients were calculated across all 24 lambs.

²A655sc IR camera (FLIR Systems Inc.).

³Average of two hand-held IR guns: Model FB61354 (Fisher Scientific) and Model TN418LD (Metris Instruments).

IR, infrared; RH, relative humidity; THI, temperature–humidity index.