. 2020 Jan 24;99(2):812–819. doi: 10.1016/j.psj.2019.12.027

Table 4.

Effect of age at photostimulation on fertility and hatching efficiency of White Leghorn breeder hens at 50 wk of age.

Item	Age at photostimulation (wk)				SEM	P-value
Item	16	18	20	22	SEM	P-value
Fertility, %	97.83	98.75	97.62	96.00	1.07	0.90
Hatchability of fertile eggs, %	71.33	88.94	84.66	90.68	3.39	0.14
Hatchability, %	69.65^b	87.85^a	82.51^a	86.86^a	2.98	0.04

Data are the mean of 2 replicates.

^a,b

Values within a row with different superscripts differ significantly at P < 0.05.