Effects and interactions of dietary lysine and apparent nitrogen corrected metabolizable energy on yellow-feathered broiler breeder hens

Table 6 Effects of dietary lysine and AMEn on egg quality of yellow-feathered broiler breeders¹

Treatment		Shape index	Eggshell thickness, mm	Shell strength, kgf	Relative yolk weight, %	Yolk color	Albumen height, mm	Haugh unit
Lys, %	AMEn, MJ/kg	Shape index	Eggshell thickness, mm	Shell strength, kgf	Relative yolk weight, %	Yolk color	Albumen height, mm	Haugh unit
0.56	11.50	1.30	3.92	0.335	31.70	10.15	5.33	70.91
0.68	11.50	1.30	4.98	0.359	31.99	10.04	5.43	70.86
0.80	11.50	1.30	4.17	0.344	32.12	9.82	5.42	70.16
0.92	11.50	1.31	3.91	0.323	32.76	9.68	5.95	75.01
1.04	11.50	1.30	3.86	0.321	32.66	9.90	5.68	73.61
0.56	11.10	1.30	4.57	0.340	31.36	9.40	5.88	74.91
0.68	11.10	1.31	4.65	0.345	31.93	9.06	5.03	67.59
0.80	11.10	1.29	4.44	0.341	32.23	9.40	5.23	69.76
0.92	11.10	1.30	4.52	0.341	31.43	9.44	5.34	70.12
1.04	11.10	1.32	4.18	0.333	31.95	9.61	5.32	70.41
SEM		0.01	0.19	0.00	0.36	0.14	0.28	2.45
Main effect
0.56		1.29	4.32^bc	0.337^bc	31.36	9.80	5.73	74.06
0.68		1.30	4.82^a	0.361^a	31.68	9.54	5.23	69.28
0.80		1.29	4.45^b	0.344^ab	31.92	9.68	5.60	73.25
0.92		1.31	4.33^bc	0.335^c	32.09	9.63	5.85	74.64
1.04		1.32	4.04^c	0.327^d	32.19	9.78	5.60	73.07
SEM		0.01	0.13	0.00	0.26	0.10	0.19	1.73
	11.10	1.30	4.57^a	0.34	31.64	9.42^b	5.49	71.97
	11.50	1.30	4.21^b	0.34	32.06	9.95^a	5.71	73.75
	SEM	0.01	0.08	0.00	0.16	0.06	0.12	1.09
Source of variation
Lys²		0.326	< 0.001	< 0.001	0.116	0.130	0.126	0.090
Linear		0.119	0.010	< 0.001	0.045	0.909	0.805	0.745
Quadratic		0.619	0.003	< 0.001	0.062	0.619	0.900	0.845
AMEn		0.656	0.001	0.083	0.064	0.000	0.158	0.181
Lys × AMEn		0.124	0.053	< 0.001	0.101	0.003	0.074	0.155
Linear Lys × AMEn		0.784	0.703	0.027	0.232	0.002	0.104	0.149
Quadratic Lys × AMEn		0.761	0.216	0.118	0.639	0.936	0.228	0.423

Quadratic regression equations based on supplemental lysine level (%):
(1) Eggshell thickness (mm) = −5.57 lysine² + 8.02 lysine + 1.64, P = 0.003, R² = 0.087, which yielded optimized lysine level as 0.72%
(2) When AMEn is 11.50 MJ/kg, eggshell strength (kgf) = −0.29 lysine² + 0.41 lysine + 0.20, P < 0.001, R² = 0.305, which yielded optimized lysine level as 0.71%; When AMEn is 11.10 MJ/kg, eggshell strength (kgf) = −0.11 lysine² + 0.16 lysine + 0.29, P = 0. 158, R² = 0.054
Lys Lysine, AMEn Nitrogen-corrected apparent metabolizable energy
^a−dMeans within a main effect, without common superscripts differ significantly (P < 0.05)
¹For the interaction effect, values are means of 6 replicates each with 3 eggs each. For the main effects, values are means of 12 replicates each with 3 eggs or 40 replicates each with 3 eggs, respectively
²When lysine, the treatment effect was significant, linear and quadratic effects were tested

ISSN: 2049-1891