Diets were determined according to Ross requirements
manual and using UFFDA software. The
starter diet with 3334 kcal ME/kg and 25.12% crude
protein (CP) was fed for the 1 to 10 days. A grower diet
with 3150 kcal ME/kg and 22.10% CP was fed from 11
to 24 days and a finisher diet with 3200 kcal ME/kg
and 19.76% CP was fed from 25 to 42 days. The birds
were randomly distributed into five groups with four
replicates (each consisting of 15 broilers). The control
group was fed by basal diet with no additive; the feed
for the next three groups were treated by 1.5%, 2%
and 2.5% Aloe vera gel respectively, and the fifth
group was fed by a diet containing 15 ppm antibiotic
(virginiamycin).