Evaluation of the heat shock protein 70 gene expression in brain, T4 hormone, immune characterization and performance parameters on broilers chicken fed different levels of Descurainia sophia under acute heat stress conditions

Heat stress is one of the most important effective factors on performance and health and exposure to heat stress is one of the major challenges in poultry industry. Therefore, consuming compounds with antioxidant properties such as herbs are recommended to reduce heat stress effects. A total of 300 one-day-old broiler chicks (Hubbard) were randomly divided to four treatments and five replicates due to the investigate of different levels Descurainia sophia on performance, immune system, T4 thyroid hormone and responses of HSP70 in broiler’s brain under acute heat stress condition. Treatments were included: control treatment (basal diet), basal diet with 0.5% Descurainia sophia, basal diet with 1% Descurainia sophia and basal diet with 2% Descurainia sophia. Heat stress were exposed on d 35 to 42 (34±1˚C) for 4 hours. In order to evaluate the hormone parameters, immune system and molecular experiments five chickens from each treatment were slaughtered and blood and brain sampling were performed on d 42 of experiment. The results of experiment showed that the treatments had no significant difference on performance parameters and lymphoid organs weight in poultry (P>0.05). The least ratio of heterophile and the maximum ratio of lymphocyte were observed in 1% and 2% Descurainia sophia treatments and increasing the expression of HSP70 and T4 hormone concentration were observed in 2% Descurainia sophia treatment (P<0.05). In conclusion, the results showed that 1% and 2% Descurainia sophia is considered as a reducing agent in heat stress injuries and could be used as supplement and feed additive in poultry nutrition.