Table 1. The dietary nutrient levels for Pekin duck at different stages.

Nutritional items	1 week∽2 weeks	3weeks∽5 weeks	6 weeks∽7 weeks
Apparent metabolizable energy, MJ/kg	12.14	12.14	12.35
Crude protein, %	20.0	17.5	16.0
Calcium, %	0.90	0.85	0.80
Total phosphorus, %	0.65	0.60	0.55
Na, %	0.15	0.15	0.15
Cl, %	0.12	0.12	0.12
Lysine, %	1.10	0.85	0.65
Methionine, %	0.45	0.40	0.35
Methionine + Cystine, %	0.80	0.70	0.60
Threonine, %	0.75	0.60	0.55
Tryptophan, %	0.22	0.19	0.16
Arginine, %	0.95	0.85	0.70
Isoleucine, %	0.72	0.57	0.45
Vitamin A, IU/kg	4000	3000	2500
Vitamin D3, IU/kg	2000	2000	2000
Vitamin E, IU/kg	20	20	10
Vitamin K3, mg/kg	2.0	2.0	2.0
Vitamin B1, mg/kg	2.0	1.5	1.5
Vitamin B2, mg/kg	10	10	10
Niacin, mg/kg	50	50	50
Pantothenic acid, mg/kg	20	10	10
Vitamin B6, mg/kg	4.0	3.0	3.0
Vitamin B12, mg/kg	0.02	0.02	0.02
Biotin, mg/kg	0.15	0.15	0.15
Folic acid, mg/kg	1.0	1.0	1.0
Choline, mg/kg	1000	1000	1000
Cu, mg/kg	8.0	8.0	8.0
Fe, mg/kg	60	60	60
Mn, mg/kg	100	100	100
Zn, mg/kg	60	60	60
Selenium, mg/kg	0.30	0.30	0.20
I, mg/kg	0.40	0.40	0.30