Table 3.

Actual amino acid intake of experimental treatments¹.

Nutrient, g/d	Week 20 to 29					Week 20 to 39					Hy-Line5
	SP2	RP3	RP-Arg4	RP-GAA4	RP-Cit4	SP	RP	RP-Arg	RP-GAA	RP-Cit
GAA	0.00	0.00	0.00	0.63	0.00	0.00	0.00	0.00	0.54	0.00	–
Cit	0.00	0.00	0.00	0.00	0.41	0.00	0.00	0.00	0.00	0.38	–
Arg	1.17	0.69	1.09	0.67	0.69	1.18	0.67	1.04	0.58	0.64	0.92
Lys	1.16	1.20	1.20	1.16	1.19	1.17	1.15	1.14	1.00	1.11	0.90
Met	0.54	0.61	0.61	0.59	0.61	0.54	0.59	0.58	0.51	0.57	0.45
Cys	0.37	0.30	0.31	0.30	0.30	0.38	0.29	0.29	0.26	0.28	–
Met + Cys	0.91	0.91	0.92	0.89	0.91	0.92	0.88	0.87	0.77	0.85	0.81
Trp	0.28	0.22	0.22	0.22	0.22	0.28	0.21	0.21	0.19	0.21	0.19
Ile	0.84	0.79	0.79	0.76	0.78	0.85	0.76	0.75	0.66	0.73	0.66
Thr	0.81	0.81	0.81	0.79	0.80	0.81	0.78	0.77	0.68	0.75	0.69
Val	0.98	0.93	0.93	0.90	0.92	0.99	0.89	0.88	0.78	0.86	0.80
His	0.49	0.34	0.34	0.33	0.34	0.50	0.33	0.32	0.28	0.32	–
Phe	0.93	0.62	0.62	0.60	0.62	0.93	0.60	0.59	0.52	0.58	–
Leu	1.60	1.11	1.12	1.08	1.11	1.62	1.07	1.06	0.93	1.04	–
Gly	0.84	0.60	0.60	0.58	0.59	0.85	0.58	0.57	0.50	0.56	–
Tau	0.16	0.18	0.18	0.17	0.17	0.17	0.17	0.17	0.15	0.16	–
Ser	0.78	0.52	0.52	0.50	0.51	0.79	0.50	0.49	0.43	0.48	–
Glu	4.02	3.12	3.13	3.03	3.10	4.05	3.01	2.97	2.61	2.90	–
Pro	1.28	1.05	1.06	1.02	1.05	1.29	1.02	1.00	0.88	0.98	–
Ala	1.00	0.70	0.71	0.68	0.70	1.00	0.68	0.67	0.59	0.65	–
Tyr	0.61	0.39	0.39	0.38	0.38	0.61	0.37	0.37	0.32	0.36	–

GAA = guanidinoacetic acid; Cit = citrulline.

¹Values of all amino acids presented were total amino acids.

²SP: standard protein diet with 17% CP.

³RP: reduced protein diet with 13% CP.

⁴l-Arg, GAA and l-Cit were added on top of the RP diets at 0.35%, 0.46% and 0.35% in diets, RP-Arg, RP-GAA and RP-Cit, respectively, to the level of Arg in SP.

⁵Total amino acid recommendation for commercial Hy-Line Brown layers (g/d) from 17 to 37 wk of age based on feed intake of 108 g/d (Hy-Line International, 2016).