This experiment was conducted to study the possible beneficial effects of
diazepam, a mild tranquilliser and appetite stimulator drug, on food intake and the
physiological homeostasis of broiler chicks exposed to the high ambient temperatures
of the summer months. A total of 200. one day old, unsexed Hubbard broiler chicks were used. The
chicks were allocated into five equal groups, one of them was kept as control while
the others received different gradient levels of Diazepam for 6 weeks. The results indicated that both liv~ body weight and body weight gain at the
end of the experiment (6 weeks) were significantly higher for birds at 0.5 gm/L of
drinking water than the control and the other treatment groups. Changes in live body
weight from 0 to 6 weeks of ages were 34.3; 37.7; 43.6; 40.2 and 37.9 folds for the
control; 0.25; 0.50; 0.75 and 1.0 gmlL doses, respectively. A significant increase in feed consumption was observed for birds treated by
0.50 gm/L of the drug at different ages. Similar trends were also observed for feed
conversion ratio. protein consumption and efficiency of protein utilization in treated
groups. A significant dose-dependent increase in T4 and T3 levels at 4 and 6 weeks of
age was also observed. Plasma total protein; triglycerides; cholesterol; creatinine;
GOT and GPT levels were significantly different among treatment groups. except for
the lower dose, and the control one. Rectal temperature was significantly higher in the control and the 0.25 gmlL of
diazepam groups than the other groups. Moreover. mortality rate was higher (10%) in
the control group than in all treatment groups, where no mortalities occurred. It could be concluded that, under hot summer conditions, water
supplementation of 0.50 gmlL of diazepam is desirable to stimulate eating behaviour
of broiler chicks, and to maintain their physiological equilibrium during high ambient
temperature.