. 2021 Jan 28;100(4):101026. doi: 10.1016/j.psj.2021.101026

Table 2.

The effect of flock age, preincubation heat treatment, and turning during 14 d storage on hatchability of fertile eggs, early, middle, and late embryonic mortality, second-grade chick, and contaminated egg percentages.

Item	n¹	Hatchability of fertile eggs	Embryonic mortality			Cull²	Cont³
Item	n¹	Hatchability of fertile eggs	Early	Middle	Late	Cull²	Cont³
Flock age⁴		-----------------(%)------------------
Young	24	81.60^a	10.16^a	1.27^b	5.43^b	1.30^b	0.23^b
Old	24	79.24^b	7.90^b	2.10^a	6.68^a	2.39^a	1.68^a
Preincubation heat treatment⁵
Control	24	78.50^b	9.81^a	1.73	6.65^a	2.34^a	0.97
SPIDES	24	82.34^a	8.26^b	1.64	5.46^b	1.36^b	0.94
Turning treatment⁶
0 times/day	24	79.57^b	8.74	1.84	6.78^a	2.08	0.92
4 times/day	24	81.28^a	9.33	1.53	5.33^b	1.62	1.00
SEM		0.616	0.351	0.169	0.338	0.261	0.124
P value
FA		0.008	0.001	0.001	0.010	0.004	0.001
PHT		0.001	0.002	0.722	0.015	0.009	0.865
TT		0.045	0.240	0.200	0.003	0.213	0.664
FA × PHT		0.689	0.174	0.710	0.763	0.512	0.415
FA × TT		0.268	0.421	0.884	0.053	0.460	0.263
PHT × TT		0.726	0.702	0.718	0.738	0.971	0.868
FA × PHT × TT		0.583	0.338	0.412	0.595	0.254	0.869

^a,bMeans within a column with different superscripts differ significantly (P ≤ 0.05).

There were 24 replicate trays for per treatment.

Cull is the second-grade chick percentage, as calculated based on the number of fertile eggs in each replicate tray.

Contaminated egg percentages were calculated based upon the number of fertile eggs in each replicate tray.

⁴

Flock age (FA): young = 29 wk, old = 58 wk.

⁵

Preincubation heat treatment (PHT): control = not heated during storage, and short period of incubation during egg storage (SPIDES) = heated over 32°C EST for 3.5 h and remained at 35°C for 2.5 h on day 5 after egg collection.

⁶

Turning treatment (TT): 0 or 4 times/day during the storage period.