Table-2.

Effect of non-ventilation periods in the incubators on hatchability, spread of hatch, hatch window, and hatched chick weight.

Traits	NV			V	p-value
	0–3 d (NV1)	0–6 d (NV2)	0–9 d (NV3)	0–18 d
Hatchability of fertile eggs %	89.15a ± 1.37	90.05a ± 1.09	92.03a ± 0.73	80.18b ± 1.46	0.014
Spread of hatch1
Early hatch %	18.27 ± 0.23	19.01 ± 0.43	18.05 ± 0.05	17.99 ± 0.29	0.215
Middle hatch%	72.43c ± 0.36	74.00b ± 0.32	77.61a ± 0.22	47.00d ± 0.47	0.001
Late hatch%	5.97b ± 0.35	4.99b ± 0.35	2.48c ± 0.28	21.99a ± 0.28	0.001
Post late hatch%	3.32b ± 0.20	1.99c ± 0.35	0.99d ± 0.01	13.0a ± 0.38	0.001
Hatch window (h)
Average hatch time	489.29b ± 1.27	484.77b ± 2.28	478.84c ± 2.37	496.79a ± 1.46	0.001
Range of hatch time2	42.85b ± 1.59	41.07b ± 3.18	39.42b ± 1.82	47.34a ± 0.73	0.001
Hatched chick weight (g)
Chick weight at hatch	38.26b ± 0.97	39.70ab ± 0.42	40.09a ± 0.94	36.89b ± 0.47	0.002
Chick weight at pull-out	36.18a ± 0.97	37.95a ± 1.08	38.90a ± 1.23	34.75b ± 0.34	0.001
Chick weight loss %	5.43a ± 1.30	4.40b ± 1.29	2.96c ± 1.40	5.80a ± 0.06	0.001

^a,b,cMeans having different letters in the same row are significantly different (p ≤ 0.05), 1-Spread of hatch: V (early: 473.12–485.12 h, peak: 485.12–97.12 h, late: 497.12–509.12 h and post-late: hatch: 509.12–520.46 h); NV1 (early: 467.87–479.87 h, peak: 479.87–491.87 h, late: 491.87–503.87 h, and post-late hatch: 503.87–510.72 h); NV2 (early: 464.24–476.24 h, peak: 476.24–488.24 h, late: 488.24–500.24 h, and post-late hatch: 500.24–505.31 h), and NV3 (early: 459.13–471.13 h, peak: 471.13–483.13, late: 483.13–495.13 h, and post-late hatch: 495.13–498.55 h). 2-Range of hatch time=maximum hatch time - minimum hatch time. d=Day. NV=Non-ventilated, V=Ventilated