Table 1. Effect of dietary Bacillus subtilis and oregano essential oil supplementation on production performance of late-phase laying hens

		Egg production(%)	Egg weight(g)	Egg mass	Feed consumption(g/bird/day)	Feed conversion ratio
Egg production
H		94.72^a	63.76	60.40^a	128.17	2.13
A		90.14^b	63.77	57.47^b	127.10	2.22
SEM		0.836	0.576	0.747	1.241	0.031
Additive
CON		90.94	63.82	58.05	128.14	2.22
BS		93.29	63.40	59.13	126.94	2.15
OEO		93.07	64.08	59.63	127.81	2.15
SEM		1.024	0.706	0.915	1.520	0.039
Egg production×Additive
H	CON	95.09^a	63.91	60.83	129.82^ab	2.14
	BS	94.89^a	63.11	59.87	130.24^ab	2.18
	OEO	94.20^a	64.26	60.51	124.44^ab	2.06
A	CON	86.80^b	63.72	55.27	126.47^ab	2.30
	BS	91.69^a	63.69	58.40	123.64^b	2.12
	OEO	91.94^a	63.90	58.74	131.19^a	2.23
SEM		1.448	0.998	1.294	2.150	0.055
P-values
Egg production		0.0007	0.9896	0.0105	0.5488	0.0528
Additive		0.2225	0.7944	0.4707	0.8475	0.3227
Interaction		0.0499	0.8824	0.2323	0.0129	0.0864

Means in same rows with different superscripts are significantly different (P<0.05).
H, high egg production; A, average egg production; CON, fed a basal diet; BS, fed basal diet plus 3 × 10⁸ CFU/kg feed Bacillus subtilis; OEO, fed basal diet plus 0.3 g/kg feed oregano essential oil.