Similar to chickens, ingredients supplying dietary energy
and amino acids (AA) represent most of the diet
cost for meat ducks. Therefore, providing diets formulated
to contain AME and AA at optimum concentrations
to meat ducks may increase profits by decreasing
feed cost and/or increasing meat yield. Xie et al.
(2010) reported that the AME requirement of White
Pekin ducklings from 1 to 21d of age for optimal feed
to gain ratio (FCR) was 12.63MJ/kg when dietary protein
was 20.5% (1.1% lysine). The AME requirements
of White Pekin ducks from 15 to 42d of age for optimal
body weight (BW) gain and FCR was 12.57 and
12.67 MJ/kg when dietary protein was 18% (0.9% lysine),
respectively, and abdominal fat increased when
dietary AME was above 11.29MJ/kg (Fan et al., 2008).
Sritiawthai et al. (2013) observed dietary 18% crude
protein (CP) and 11.29 MJ ME /kg were the appropriate
concentrations for improved feed efficiency and
presented the best final BW and FCR from 1 to 14 d of
age in Cherry Valley ducks. A significant interaction between
protein and energy indicated the importance of a