Ghayth  Jazaa^(1)* and  Zouher  Jabbour⁽¹⁾

(1). Department of Animal Production, Faculty of Agricultural Engineering, Tishreen University, Lattakia, Syria.

(* Corresponding author: Ghayth Jazaa, E.mail: ghayth.jazaa@tishreen.edu.sy)

Received:20/08/2023          Accepted: 5/04/2023

Abstract: 

The study was conducted on 180 one-day-old Ross chicks, without distinguishing between males and females, to determine the effect of heat stress on the level of cortisol hormone in the blood serum of broiler chickens. The chicks were divided into two groups; each group includes 90 chicks. The control group was under ideal temperature conditions suitable for broiler chickens throughout the experiment, while the heat stress group was subjected to heat stress from the age of 22 days to the age of 42 days for 7 hours a day during the day from ten in the morning until five in the evening at a temperature rate of 31 ± 1, with a relative humidity ranging between 70-80%, and a nursery density of 10 birds per square meter. At the end of the experiment, at the age of 42 days, the level of cortisol in the serum was measured. The results showed that there was a significant (P<0.05) increase in serum cortisol concentration in the stress group (5.81 ± 0.06) ng/mL compared to the control group (2.01 ± 0.04) ng/mL. We conclude, through the aforementioned results, the close relationship between heat stress, high cortisol concentration, and physiological homeostasis in birds exposed to stress.

Keywords: Stress, Heat Stress, Broiler, cortisol.

Full paper in Arabic: pdf