Table 3. Influence of crating density and weather conditions on respiratory frequency of broilers during transportation

Crating density	Weather1	Respiratory frequency (count/min)
10.3 birds/m2	Summer	50.00
11.5 birds/m2		50.00
12.8 birds/m2		52.00
14.1 birds/m2		56.00
15.4 birds/m2		60.00
10.3 birds/m2	Winter	48.00
11.5 birds/m2		46.00
12.8 birds/m2		46.00
14.1 birds/m2		46.00
15.4 birds/m2		48.00
SEM		0.721
Main effect
Crating density
10.3 birds/m2		49.00
11.5 birds/m2		48.00
12.8 birds/m2		49.00
14.1 birds/m2		51.00
15.4 birds/m2		54.00
SEM		1.008
Weather
Summer		53.60
Winter		46.80
SEM		0.811
P-value
Crating density		0.368
Weather		<0.001
Crating density × Weather		0.200
Crating density (linear)2		0.070
Crating density (quadratic)2		0.109

Weather: Summer = high ambient temperature (27°C), Winter = low ambient temperature (−9°C).
Linear and quadratic effects of increasing crating density with the pooled data of broilers from different weather.
SEM, standard error of the mean.