Table 4. Analyzed amino acid compositions in feather of 29-day-old male broilers fed different dietary methionine concentrations (as-is basis)¹⁾

Item	Dietary SID methionine concentration (%)						SEM	p-value
	0.40	0.45	0.50	0.55	0.60	0.65		Linear	Quadratic
Indispensable amino acid
Arginine	6.5	6.4	6.7	6.3	5.1	6.5	0.64	0.44	0.80
Histidine	0.7	0.8	0.7	0.7	0.7	0.7	0.05	0.68	0.60
Isoleucine	4.4	4.4	4.4	4.2	4.3	4.4	0.06	0.92	0.05
Leucine	7.6	7.6	8.1	7.6	7.9	7.7	0.24	0.69	0.40
Lysine	2.2	2.3	2.1	2.2	2.1	2.2	0.16	0.67	0.80
Methionine	0.6	0.6	0.6	0.6	0.6	0.6	0.04	0.73	0.44
Phenylalanine	4.4	4.4	4.6	4.3	4.6	4.5	0.10	0.79	0.71
Threonine	4.5	4.5	4.5	4.3	4.5	4.5	0.06	0.87	0.16
Valine	6.9	6.8	7.1	6.7	7.0	6.9	0.16	0.82	0.93
Dispensable amino acid
Alanine	4.1	4.0	4.4	4.1	4.3	4.1	0.15	0.65	0.29
Aspartic acid	6.5	6.5	6.6	6.4	6.6	6.5	0.07	0.90	0.92
Cysteine	6.3	6.2	6.4	6.0	6.5	6.1	0.18	0.78	0.74
Glutamic acid	10.4	10.4	10.3	10.1	10.4	10.4	0.14	0.72	0.25
Glycine	6.6	6.6	7.0	6.6	6.9	6.7	0.20	0.59	0.53
Proline	9.1	9.0	9.4	8.7	9.2	9.2	0.25	0.76	0.68
Serine	9.9	9.7	10.2	9.6	10.1	10.0	0.34	0.84	0.83
Tyrosine	2.7	2.8	2.7	2.5	2.7	2.7	0.13	0.48	0.62

Values are least squares means of four replicate cages, with one bird per cage.
SID, standarized ileal digestible.