Table 3.

Plasma CORT and T-AOC levels of laying hens at 22, 26, 30, 34, and 38 WOA exposed to different ammonia concentrations under 20°C and 35°C.

Item1	CORT (ng/mL)	T-AOC (U/mL)
T (°C)
20	68.09 ± 1.03a	9.11 ± 0.32a
35	66.56 ± 0.86b	8.15 ± 0.27b
AC (ppm)
≤5	65.90 ± 0.94	9.94 ± 0.47a
20	65.14 ± 1.05	8.53 ± 0.33b
45	68.66 ± 1.45	7.41 ± 0.22c
WOA
22	63.37 ± 1.36b	5.87 ± 0.12c
26	73.06 ± 1.56a	6.04 ± 0.13c
30	69.84 ± 1.31a	6.58 ± 0.19c
34	64.05 ± 1.59b	11.17 ± 0.32b
38	62.51 ± 1.34b	13.67 ± 0.49a
P-value2
T	<0.05	<0.05
AC	NS	<0.05
WOA	<0.05	<0.05
T × AC	NS	<0.05
T × WOA	NS	<0.05
AC × WOA	<0.05	<0.05

^a–cMeans within main effects without a common letter differ (P < 0.05).

Abbreviations: CORT, corticosterone; T-AOC, total antioxidant capacity.

¹T, temperature; AC, ammonia concentration; WOA, week of age.

²NS, no significance.