TABLE 1.

Nutritional value of diet at different ages of Leizhou Black Ducks

Nutritional value	Age of ducks
	1–4 weeks	5–12 weeks	13–16 weeks
Metabolizable energy (MJ/kg)	12.1	11.4	10.4
Crude protein ≧ (%)	20.0	15.0	17.0
Crude fibre ≦ (%)	8.0	8.0	6.5
Coarse ash (%)	11.0	11.0	14.0
Calcium (%)	0.6–1.6	0.6–1.6	2.5–4.0
Total phosphorus (%)	0.3	0.3	0.4–1.5
Sodium chloride (%)	0.2–0.8	0.2–0.8	0.2–0.8
Methionine ≧ (%)	0.4	0.3	0.3