Table 6.

Feed intake and production performance responses in White Shaver laying hens during phase 1 (20 to 27 wk) and 2 (28 to 46 wk) fed a low crude protein diet with varying levels of L-Ile compared to a control (CON).

Item	Feed intake (g/D)	Hen-day egg production (%)	Egg weight (g)	Egg mass (g)	Feed conversion ratio
Phase 1
CON	97	97.6a	51.7a,b	50.6a	1.93
Ile70	95	94.3b	51.3a,b	48.6b	1.99
Ile80	98	93.8b	51.5a,b	48.6b	2.05
Ile90	96	95.4a,b	52.1a	49.9a,b	1.97
Ile100	96	97.6a	51.1b	49.8a,b	1.95
SEM	0.789	0.760	0.205	0.425	0.031
P-value	0.211	<0.001	0.004	0.003	0.097
Contrasts (P-value)
CON vs. Ile70	0.124	0.003	0.114	<0.001	0.231
CON vs. Ile80	0.492	<0.001	0.443	0.001	0.011
Linear	0.493	0.005	0.782	0.035	0.387
Quadratic	0.126	0.039	0.002	0.960	0.183
Phase 2
CON	114a	99.2a,b	58.2a	57.5	1.98a,b
Ile70	113a,b	97.7c	58.6a	57.2	1.98a,b
Ile80	116a	98.1b,c	58.0a,b	57.0	2.05a
Ile90	110b	99.6a	58.2a	58.0	1.90c
Ile100	111b	99.1a,b	57.3b	56.7	1.95b,c
SEM	0.967	0.302	0.210	0.325	0.020
P-value	<0.0001	<0.0001	0.001	0.058	<0.0001
Contrasts (P-value)
CON vs. Ile70	0.739	<0.001	0.195	0.416	0.804
CON vs. Ile80	0.119	0.013	0.558	0.216	0.013
Linear	<0.001	<0.001	<0.001	0.695	0.002
Quadratic	0.043	0.003	0.138	0.006	0.001

^a–cValues are statistically significant (P < 0.05).