Table 5.

Effect of 25OHD on laying hen egg production during the laying period.

Stages	D1 (%)	DD (%)	25D (%)	SEM	P-value
Peaking2	96.28A	92.85B	96.36A	0.49	<0.0001
Layer 2	89.49A	82.40B	90.06A	0.79	<0.0001
Layer 3	84.28	88.27	85.65	1.24	0.099
Layer 4	77.95	82	77.61	1.67	0.156
Layer 5	64.58	70.83	66.82	2.76	0.304
22–60 wk3	90.67A,B	88.53B	91.29A	0.64	0.015
61–90 wk	70.31	75.62	71.44	2.22	0.240
22–95 wk	81.04	82.41	81.9	1.22	0.740

^A,BMeans within a column with different superscripts are significantly different (P < 0.05).

Abbreviation: 25OHD, 25-hydroxyvitamin D₃.

¹D: vitamin D₃ at 2,760 IU/kg; DD: vitamin D₃ at 5,520 IU/kg; 25D: vitamin D₃ at 2,760 IU/kg plus 25OHD at 2,760 IU (69 μg)/kg.

²Peaking (22–38 wk), layer 2 (39–48 wk), layer 3 (49–60 wk), layer 4 (61–75 wk), and layer 5 (76–95 wk).

³Accumulated egg production during the period indicated in the columns.