Growth performance, blood biochemistry, and mRNA expression of hepatic heat shock proteins of heat-stressed broilers in response to rosemary and oregano extracts

• Published in: Journal of thermal biology Vol. 119; p. 103791
• Main Authors: Madkour, Mahmoud, Alaqaly, Ahmed M., Soliman, Said S., Ali, Sami I., Aboelazab, Osama
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2024
• Subjects: Animal Feed - analysis; Animals; Antioxidants - metabolism; Broiler; Chickens - physiology; Diet - veterinary; Dietary Supplements; Growth; Heat shock proteins; Heat stress; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; Heat-Shock Response; Male; Oregano extract; Origanum; RNA, Messenger - metabolism; Rosemary extract; Rosmarinus; Heat shock proteins; Oregano extract; Heat stress; Rosemary extract; Growth; Broiler
• ISSN: 0306-4565; 1879-0992
• DOI: 10.1016/j.jtherbio.2024.103791

The growing interest in countering the adverse effects of heat stress in poultry using phytogenic feed additives has garnered considerable attention in recent times, this research sought to examine the impact of rosemary leaves extract (RLE) and oregano leaves extract (OLE) on the growth performance, physiological responses, and hepatic mRNA expression of heat shock proteins in broiler chickens exposed to heat stress. A total of 150 male Indian River chicks, aged one day, were randomly allocated into five equally sized groups, each consisting of six replicates. The initial group was designated as the control and was provided with the basal diet. The second and third groups (R1 and R2) were administered the basal diet enriched with 50 and 100 mg/kg of rosemary leaves extract (RLE), respectively. The fourth and fifth groups (O1 and O2) were fed the basal diet supplemented with 50 and 100 mg/kg of oregano leaves extract (OLE), respectively. These chicks were reared in a controlled environmental chamber maintained at a temperature of 32±2 °C and relative humidity of 50 ± 5 %. Ferruginol was the leading component in RLE, whereas thymol was the prevalent constituent in OLE. RLE and OLE both have high DPPH• and ABTS•+ antioxidant potential. Among the experimental groups, the fourth group (O1) showed the heaviest live body weight and the lowest feed conversion ratio, indicating improved growth performance. There was a significant reduction in plasma total lipids and LDL-cholesterol levels within the R2 and O2 groups, respectively. Enhanced total antioxidant capacity and an improvement in the T3 hormone were observed in the R1 and R2 groups. In the second and fourth groups, the mRNA expression of hsp70 and 90A were both found to be significantly downregulated, respectively. In conclusion, the addition of 50 mg/kg of oregano leaves extract (OLE) to the diets of heat-stressed broilers resulted in improved hepatic heat shock proteins, along with certain physiological responses, ultimately contributing to enhanced growth performance. •The poultry industry expresses significant concern regarding the consequences of heat stress.•Oregano leaves extract has a positive effect on the growth performance of heat-stressed broiler chickens.•Oregano and rosemary leaves extracts can modify the expression of HSPs of heat-stressed broiler chickens.