TABLE 3.

Effect of corticosterone treatment (CORT, 2 mg/kg BM for 7 days) on laying performances of hens feeding with normal diet or high-energy diet (Experiment 2)

Item	CORT	Control	Mean	Probability
Feed intake, kcal/day
Normal diet	298.6 ± 14.1a	270.7 ± 6.1b	284.8x	CORT: NS
High-energy diet	249.1 ± 3.8c	257.9 ± 3.8c	253.5y	Diet: < 0.001
Mean	273.9	264.3		CORT*Diet: 0.032
Laying rate, %
Normal diet	54.8 ± 6.3	83.3 ± 9.7	69.1	CORT: 0.046
High-energy diet	68.3 ± 12.8	82.9 ± 6.2	75.6	Diet: NS
Mean	61.5n	83.1m		CORT*Diet: NS
Egg production, g/day/hen
Normal diet	31.9 ± 3.8	47.9 ± 6.9	39.9	CORT: 0.056
High-energy diet	38.9 ± 7.2	48.3 ± 4.0	43.6	Diet: NS
Mean	35.4	48.1		CORT*Diet: NS
Egg weight, g
Normal diet	58.2 ± 0.3	58.1 ± 0.7	58.2	CORT: NS
High-energy diet	57.0 ± 0.5	56.2 ± 0.5	56.6	Diet: NS
Mean	57.6	57.1		CORT*Diet: NS

Mean ± SE (n = 3). NS, not significant.

^{a, b, c}Means with different superscript letters are significantly different, P < 0.05.

^{x, y}Means with different superscript letters are significantly different, P < 0.05.

^{m, n}Means with different superscript letters are significantly different, P < 0.05.