The present study was carried out to investigate the effect of using rice
polishings (RP) in broiler diets on the performance of chicks. Five levels of RP (0.0,
10, 20, 30 or 40%) were used in five starter and five grower diets. All experimental
diets were used with or without phytase supplementation (0.0 or 0.4 kg/ton feed). The
experimental diets were isoenergetic-isonitrogenous (the starter diets contained ME of
about 3200 kcal/kg and CP of about 23%, whereas, the grower diets had ME of about
3100 kcal/kg and CP of about 20%). Three hundred and thirty, one-day-old, broiler-
type Hubbard chicks were randomly divided into ten equal experimental groups of 3
replications each. The chicks were fed the starter diets ad libitum up to 21 day-old,
then they were switched to the grower diets from 22 to 42 days of age. The criteria of response were live body weight, weight gain, feed intake, feed
conversion ratio, mortality rate, carcass traits, nutrients digestibility, some blood
constituents (plasma glucose, total protein, total lipids, cholesterol and inorganic
phosphorus) and economic efficiency. The obtained results can be summarized as
follows: - Using RP in broiler diets up to 40% improved the economic efficiency and
did not affect carcass traits, nutrients digestibility, mortality rate or blood parameters of
chicks. However, when RP was added at inclusicn rate of 40% of the diet, both
marketing live body weight and feed intake of broiler chicks were significantly
depressed but the feed conversion ratio was not affected. Supplementation of the
diets with phytase significantly increased the body weight of chicks, body weight gain,
feed intake and improved the feed conversion ratio. However, enzyme
supplementation had no effect on carcass traits, nutrients digestibility and blood
constituents in chicks, or on the economic efficiency of the experimental diets. From
the previous results, it can be concluded that rice polishings can be used up to 30% of
the corn-soybean broiler diets by which good results of broiler performance, carcass
traits and economic efficiency can be obtained. Supplementation of the diets with
phytase significantly improved the performance of broiler chicks.