. 2019 Dec 19;10(1):15. doi: 10.3390/ani10010015

Table 3.

Effect of different UVB-LED light exposure durations on egg quality.

Parameters	Duration (Week)	UV-LED Exposure Time
Parameters	Duration (Week)	1 h/day	2 h/day	3 h/day	0 h/day
Egg shell thickness (mm)	0 week	0.28 ± 0.02	0.28 ± 0.01	0.27 ± 0.01	0.26 ± 0.02
	4 weeks	0.27 ± 0.03	0.27 ± 0.02	0.29 ± 0.02	0.30 ± 0.01
	8 weeks	0.26 ± 0.02	0.26 ± 0.01	0.28 ± 0.01	0.28 ± 0.02
Egg shell weight (g)	0 week	6.5 ± 0.37	6.8 ± 0.26	6.6 ± 0.54	6.4 ± 0.64
	4 weeks	6.4 ± 0.72	6.8 ± 0.40	6.9 ± 0.84	7.0 ± 0.35
	8 weeks	6.0 ± 0.43	6.3 ± 0.26	6.4 ± 0.63	6.7 ± 0.39
Egg weight (g)	0 week	63.9 ± 2.55	66.9 ± 4.77	64.5 ± 4.75	59.6 ± 3.75
	4 weeks	64.3 ± 3.34	68.3 ± 1.93	65.3 ± 4.65	65.0 ± 3.23
	8 weeks	60.0 ± 1.97	63.7 ± 2.14	61.1 ± 4.77	64.2 ± 1.14
Egg yolk weight (g)	0 week	16.7 ± 1.00	16.9 ± 1.03	16.7 ± 0.98	15.9 ± 1.37
	4 weeks	16.9 ± 1.01	18.5 ± 1.21	18.0 ± 1.17	17.6 ± 0.64
	8 weeks	17.8 ± 0.56	18.2 ± 0.97	17.4 ± 1.92	17.9 ± 1.07
Egg shell strength (kg/cm³)	0 week	2.88 ± 0.53 ^b,A	2.77 ± 0.65 ^c,A	3.17 ± 0.48 ^a,A	3.10 ± 0.71 ^a,B
	4 weeks	2.72 ± 0.64 ^c,B	2.50 ± 0.40 ^d,B	2.95 ± 1.08 ^b,B	3.30 ± 0.58 ^a,A
	8 weeks	2.70 ± 0.71 ^b,B	2.30 ± 0.79 ^d,C	2.56 ± 0.56 ^c,C	3.37 ± 0.85 ^a,A

During the 8 weeks experiment, UVB-LED light supplementation was provided for the birds in the three treatment groups (1 h, 2 h, and 3 h per day), while the control group was not exposed to UVB-LED light. Data are presented as the means ± standard error (SE). ^{a, b, c, d}: Within a row, different lowercase letters indicate significant differences (p < 0.05). ^{A, B, C}: Within a column, different capital letters indicate significant differences (p < 0.05).