The response to dietary arginine was determined for ducks from 1 to 21 d of age in the present experiment.
Six hundred thirty 1-d-old male Z4 White Pekin ducks with an initial BW of 57.63 g obtained from Pekin duck breeding center in Chinese Academy of Agricultural
Sciences were randomly allocated to 10 dietary-arginine
treatments with 7 replicate pens of 9 birds per pen.
Experimental birds were kept in plastic-wire-floor pens
in an environmentally controlled duck house; the size
of each pen was 100 × 100 × 40 cm. The temperature
was set at 28°C from 1 to 3 d of age, at 26°C from 4 to
7 d of age, at 25°C from 8 to 14 d of age, and at 22 to
20°C from 15 to 21 d of age. All birds had free access
to pelleted feed, and drinking water and lighting was
provided continuously.