Table 4.

The mandibular ramus characteristics of crossed beaks (n = 8) and normal beaks (n = 4) in Beijing-You chickens at 70 d of age.

Group		Crossed beaks		Normal beaks	SEM	P-value
		LEFT	RIGHT	NORMAL
Mandible weight, g	Left	0.38	0.4	0.44	0.01	0.17
	Right	0.36	0.42	0.44	0.02	0.28
	SEM	0.01	0.02	0.02
	P-value	0.32	0.41	0.38
MR1 thickness, mm	Left	1.51A,a	1.11B,b	1.10b	0.07	<0.01
	Right	1.12B,b	1.59A,a	1.14b	0.08	<0.01
	SEM	0.08	0.11	0.03
	P-value	<0.01	0.04	0.14
MR width, mm	Left	4.58a,b	4.24b	4.94a	0.11	0.03
	Right	4.30	4.52	4.89	0.14	0.28
	SEM	0.08	0.19	0.07
	P-value	0.13	0.23	0.49
MR length, cm	Left	2.27B,b	3.41A,a	3.43a	0.18	<0.01
	Right	3.39A,a	2.42B,b	3.48a	0.16	<0.01
	SEM	0.22	0.19	0.05
	P-value	<0.01	<0.01	0.10
MR length difference (left-right), cm		−1.12c	0.99a	−0.05b	0.29	<0.01
Symmetry2, %		−19.83c	17.05a	−0.78b	5.01	<0.01

^a–cValues within a row with different superscripts differ significantly at P < 0.05.

^{A, B}Values within a column of each trait with different superscripts differ significantly at P < 0.05.

¹MR, Mandibular ramus.

²Symmetry (%) = (left MR length − right MR length)/(left MR length + right MR length) × 100.