. 2020 Jun 22;99(9):4384–4397. doi: 10.1016/j.psj.2020.05.028

Table 7.

Egg quality of laying hens as affected by different housing systems, essential oils, and their interaction during the experiment.

Items	Shell thickness (μm)	Shell %	Yolk %	Albumin %	Egg shape index%	Yolk index%	Haugh unit
Housing system
Cage	0.376	8.92	29.02	62.04	77.74	22.47	83.67
Floor	0.360	8.65	28.85	62.49	76.83	22.49	81.30
Essential oils (EOs)
0	0.359^c	8.52^b	28.53^b	62.94^a	75.59^c	23.54^a	79.72^d
Thymol	0.371^a,b	8.92^a	29.10^a	61.96^c	77.98^a	22.29^b	83.38^b
Carvacrol	0.368^b	8.69^b	28.77^b	62.53^b	77.20^b	22.43^b	81.53^c
Eugenol	0.374^a	9.01^a	29.33^a	61.64^c	78.37^a	21.66^c	85.32^a
Housing × EOs
Cage
0	0.363^c	8.71	28.60	62.67	76.01	23.28^a	80.80
Thymol	0.381^a	9.07	29.05	61.87	78.59	22.09^b	84.21
Carvacrol	0.377^b	8.85	28.82	62.30	77.53	22.77^b	82.73
Eugenol	0.382^a	9.05	29.60	61.33	78.84	21.75^c	86.95
Floor
0	0.356^d	8.32	28.45	63.21	75.19	23.81^a	78.64
Thymol	0.362^c	8.78	29.15	62.05	77.38	22.08^b	82.56
Carvacrol	0.359^d	8.52	28.72	62.75	76.86	22.08^b	80.34
Eugenol	0.366^c	8.98	29.06	61.95	77.89	21.57^c	83.68
SEM	0.01	0.07	0.117	0.13	0.16	0.11	0.44
Portability
Housing system	<0.001	<0.001	0.039	<0.001	<0.001	0.853	<0.001
EOs	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
Housing × EOs	0.001	0.222	0.07	0.420	0.413	<0.001	0.339

^a-cMeans in the same column within each classification bearing different superscript lowercase letters are significantly different (P < 0.05 or 0.01).