Table 6. Effect of dietary Bacillus subtilis and oregano essential oil supplementation on intestinal morphology(H&E stain) of late-phase laying hens

		Villi height (μm)	Crypt depth (μm)	Villi height / Crypt depth
Egg production
H		592.80	103.13^a	5.85^b
A		610.76	99.06^b	6.22^a
SEM		8.501	1.402	0.078
Additive
CON		584.23^b	111.55^a	5.27^b
BS		622.20^a	98.59^b	6.37^a
OEO		598.89^ab	93.15^c	6.45^a
SEM		10.412	1.717	0.096
Egg production×Additive
H	CON	587.90^bc	117.87^a	5.00^c
	BS	631.38^a	101.53^bc	6.28^a
	OEO	559.11^c	89.99^d	6.26^a
A	CON	580.57^bc	105.23^b	5.54^b
	BS	613.02^ab	95.64^cd	6.47^a
	OEO	638.67^a	96.32^cd	6.64^a
SEM
P-values
Egg production		0.1375	0.042	0.0011
Additive		0.0368	<.0001	<.0001
Interaction		0.0018	0.0006	0.4553

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.