. 2018 Sep 11;96(12):5064–5074. doi: 10.1093/jas/sky355

Table 3.

Egg quality traits of laying ducks during the high-temperature and recovery periods¹

Trait	Treatment
Trait	Control	Pair-fed	Constant high temperature	Intermittent high temperature	SEM	P value
High-temperature period
Shape index	1.30	1.33	1.34	1.33	0.01	0.34
Haugh units	81.74^a	83.71^a	74.99^b	74.85^b	2.10	0.01
Albumen height, mm	7.28^ab	7.33^a	6.13^b	6.20^b	0.28	< 0.01
Yolk color score	6.42^a	5.33^c	5.58^bc	6.17^ab	0.27	0.03
Yolk proportion, %	31.85	32.00	30.97	31.62	0.69	0.73
Albumen proportion, %	58.93	58.73	59.77	58.03	0.86	0.56
Shell proportion, %	9.22	9.27	9.26	9.27	0.92	0.81
Shell-breaking strength, kg.cm^-2	4.02	4.04	4.00	3.68	0.24	0.68
Average shell thickness, mm	0.33	0.32	0.32	0.33	0.01	0.60
Recovery period
Shape index	1.31	1.34	1.32	1.32	0.01	0.37
Haugh units	79.29	79.90	73.93	80.15	2.42	0.25
Albumen height, mm	6.93	6.75	6.10	6.81	0.33	0.32
Yolk color score	7.08	6.17	6.75	6.83	0.25	0.11
Yolk proportion, %	31.83^ab	33.05^a	31.15^b	30.93^b	0.51	0.04
Albumen proportion, %	59.20^a	57.60^b	59.68^a	59.96^a	0.46	0.01
Shell proportion, %	8.97	9.35	9.17	9.10	0.16	0.37
Shell-breaking strength, kg.cm^-2	3.42	3.82	3.63	3.59	2.27	0.69
Average shell thickness, mm	0.31	0.31	0.31	0.31	0.01	0.84

^{a, b}Values within a row with different superscripts differ significantly at P < 0.05.

¹ n = 6 for each treatment.