Metabolic and respiratory chemosensitivity and brain monoaminergic responses to cold exposure in chicks subjected to thermal manipulation during incubation

Effect of thermal manipulation on embryonic development, hatching process, and chick quality under heat-stress conditions

“…Incubation conditions have a substantial impact on embryonic development, hatchability, chick quality, and posthatch performance ( Han et al, 2022 ; Rocha et al, 2022 ; Fares et al, 2023 ; Al-Zghoul et al, 2023 ). Hatchability and chick quality are 2 crucial factors that determine the success of a hatchery ( Yassin et al, 2008 ).…”

“…Hatchability and chick quality are 2 crucial factors that determine the success of a hatchery ( Yassin et al, 2008 ). Several studies have been conducted to discover strategies to improve these factors, and one of the most effective methods is temperature manipulation ( Han et al, 2022 ; Rocha et al, 2022 ; Tona et al, 2022 ; Al-Zghoul et al, 2023 ). They demonstrated that by controlling the temperature during incubation, it is possible to boost the hatchability percentage and chick quality by improving the embryo's physiological and biological functions.…”

“…Temperature, as an important environmental condition that impacts several biological functions and behavioral activities of birds, is considered the most critical incubation condition ( Han et al, 2022 ; Rocha et al, 2022 ; Yalcin et al, 2022 ). Piestun et al (2015) , Al-Zghoul and El-Bahr (2019) , and Han et al (2022) have shown that controlling the temperature during incubation can influence embryonic organ development, hatching parameters, and chick quality at the hatch.…”

“…By optimizing the temperature conditions during incubation, hatcheries can produce healthier, more robust chicks that are better suited for commercial production. Furthermore, chicks incubated in a manipulating temperature range have a higher growth rate and thermal tolerance, as well as a stronger immune system and a reduced mortality rate ( Liu et al, 2015 ; Ismail et al, 2016 ; Al-Zghoul and El-Bahr, 2019 ; Han et al, 2022 ; Ramiah et al, 2022 ; Rocha et al, 2022 ). Thermal manipulation during chicken egg incubation has been demonstrated to significantly improve birds’ metabolism, posthatch thermoregulation, and reduce the adverse effect of high ambient temperature ( Han et al, 2022 ; Ramiah et al, 2022 ).…”

“…Consequently, researchers and producers must continue investigating the best surrounding incubation conditions for their strains, and hatcheries must become more efficient to fulfill the requirements of modern/improved chick genotypes. Based on the strain and age, the embryo incubation temperature requirement changes during embryogenesis ( Rocha et al, 2022 ; Tona et al, 2022 ; Al-Zghoul et al, 2023 ). However, several studies have shown the benefits of thermal manipulation during egg incubation on broiler or layer- type chicks’ quality, such as improved productive performance ( Saleh et al, 2020 ; Han et al, 2022 ; Rocha et al, 2022 ; Al-Zghoul et al, 2023 ), but few have been interested in investigating this treatment on dual-purpose chicken breeders.…”