Table 1.

Effects of threonine deficiency and feed restriction on growth performance of ducks from 1 to 21 days of age.

Items	Thr-D	Pair-F	Thr-S	Pooled SEM	P-value
Body weight (g)	984c	1029b	1275a	12.96	<0.0001
Weight gain (g/day)	44.3c	46.3b	58.0a	0.06	<0.0001
Feed intake (g/day)	75.6b	76.26b	96.9a	1.44	<0.0001
Gain : Feed (g/g)	0.59b	0.61a	0.60ab	0.01	0.0219
Thr intake (g/day)	0.40 c	0.56 b	0.71a	0.008	<0.0001

Thr-D, threonine deficiency; Thr-S, threonine sufficiency; Pair-F, pair-fed.

^a,b,cMean values with unlike superscript letters were significantly different (P < 0.05).