The purpose of the current study was to assess the effect of rice
bran (RB) inclusion with phytase supplementation as a possible feed
ingredient in growing Muscovy ducks. One hundred Sixty two 1-dayold males Muscovy ducklings were used to evaluate the effect of
using rice bran on growth performance nutrients digestibility, some
carcass traits, some plasma constituents and economic efficiency.
The effect of RB per se was recognized compared with the control
group. The data of final body weight revealed that there were
insignificant different among the experimental groups where, ducks
fed 0.0% RB surpassed the other treated groups. Ducks fed 60% RB
had the lowest body weight by 5.7% followed by birds fed 30% RB
(2.4%) compared to the control. The same direction was observed
with body weight gain. Statistical differences were noticed with feed
conversion ratio between treated groups. The rice bran containing
diet (60%) increased feed conversion ratio by 14.2% compared to the
control. Final body weight increased significantly with dietary
phytase supplementation by (3.4%) compared to the unsupplemented diet. Growth rate value was increased significantly
with phytase supplementation by 4.6% compared to the unsupplemented diet. Rice bran and phytase supplementation interacted
significantly to affect all performance parameters except feed intake.
Phytase supplementation increased dry matter (4.58%), CP (4.32%),
EE (2.61%), NFE (4.16%), CF (7.14%), and ME (4.15%) compared
with control. Linear relationship can be noticed between RB and
small intestine (%). The abdominal fat % decreased by 16.7 % with
60% followed by 6.6% with 30% RB compared with the control.
Ducks fed phytase possessed significantly the highest dressing
(1.2%), GIT (5.66%), small intestine (3.65%), and pancreas (4.22%)
compared with the control. Dietary rice bran and phytase interacted
significantly to influence all investigated carcass traits except giblets
and abdominal fat. Liner relationship was observed between RB
inclusion diets and glucose where increasing RB levels from 0 to
60% leads to decrease glucose level by 17.32%. Glucose, total lipid
and cholesterol responded linearly where they decreased with
phytase supplement. Glucose decreased by 12.6, total lipid decreased
by 7.0% and cholesterol decreased by 3.5%. Rice bran inclusion
interacted significantly with phytase supplementation. Significant
differences among treatments groups can be noticed in EE where
ducks fed 60% rice bran was significant higher by 5 % than those fed
the control diet while EE in ducks fed 30% rice bran increased
numerically by 4% than those fed the control. The economic study
showed that lower total feed cost was noticed with 60% RB with
phytase. It can be concluded that rice bran with microbial phytase
could be used up to 60% in Muscovy ducks diets without any
harmful effect on performance and economic efficiency.