Embryonic Thermal Manipulation Affects the Antioxidant Response to Post-Hatch Thermal Exposure in Broiler Chickens

Abstract

Thermal stress is a major source of oxidative damage in the broiler chicken (Gallus gallus domesticus) due to the latter’s impaired metabolic function. While heat stress has been extensively studied in broilers, the effects of cold stress on broiler physiologic and oxidative function are still relatively unknown. The present study aimed to understand how thermal manipulation (TM) might affect a broiler’s oxidative response to post-hatch thermal stress in terms of the mRNA expression of the catalase, NADPH oxidase 4 (NOX4), and superoxide dismutase 2 (SOD2) genes. During embryonic days 10 to 18, TM was carried out by raising the temperature to 39 °C at 65% relative humidity for 18 h/day. To induce heat stress, room temperature was raised from 21 to 35 °C during post-hatch days (PD) 28 to 35, while cold stress was induced during PD 32 to 37 by lowering the room temperature from 21 to 16 °C. At the end of the thermal stress periods, a number of chickens were euthanized to extract hepatic and splenic tissue from the heat-stressed group and cardiac, hepatic, muscular, and splenic tissue from the cold-stressed group. Catalase, NOX4, and SOD2 expression in the heart, liver, and spleen were decreased in TM chickens compared to controls after both cold and heat stress. In contrast, the expression levels of these genes in the breast muscles of the TM group were increased or not affected. Moreover, TM chicks possessed an increased body weight (BW) and decreased cloacal temperature (TC) compared to controls on PD 37. In addition, TM led to increased BW and lower TC after both cold and heat stress. Conclusively, our findings suggest that TM has a significant effect on the oxidative function of thermally stressed broilers.

HSF3 and Hsp70 Expression during Post-Hatch Cold Stress in Broiler Chickens Subjected to Embryonic Thermal Manipulation

“…In contrast, some limitations of the present study include the relatively small sample size and the fact that the effect of TM on embryonic mortality and physiological parameters was not fully explored. However, the sample sizes utilized in the current study are in line with previously published reports [12,29].…”

“…Since most studies have focused on heat stress, there is a dearth of information regarding the effect of TM during post-hatch cold stress. In addition, two of our previous studies have investigated the effects of the same TM conditions (39 • C and 65% RH for 18 h daily from ED 10 to 18) and subsequent thermal stress on the expression of anti-oxidant and pro-inflammatory genes in the jejunal mucosa, liver and spleen, and the present study will add to those findings [29,30]. Consequently, the aim of the present study is to investigate the effect of TM on post-hatch cold stress on hepatic and splenic Hsp70 and HSF3 expression in commercial broilers.…”

“…Vaccination against Newcastle disease was carried out on post-hatch days 8 and 20 and vaccination against infectious bursal disease on post-hatch day 15. Figure 1 illustrates the experimental design followed in the present study, which is a modified version of a previously published protocol [29].…”

Modulation of Heat-Shock Proteins Mediates Chicken Cell Survival against Thermal Stress

“…The exposure of broiler chickens to high ambient temperatures also causes oxidative stress, with both situations leading to biological damage, multiple pathological disorders, and impaired growth performance. Heat stress is a major source of oxidative damage in commercial strains of meat-and egg-type chicken by altering the oxidative status in several tissue types, leading to impaired metabolic function [ 124 ] and postmortem meat characteristics [ 125 , 126 ]. Acute [ 25 , 27 ] and chronic [ 27 ] heat stress associated with oxidative stress generation in the skeletal muscle of meat-type chicken significantly impairs growth and body weight.…”

Effects of breeder age and short-term temperature stimulation during incubation on performance, organ weight, and carcass yield in male and female broilers

“…During critical incubation periods, temperature can influence embryonic development with lasting effects (Tzschentke & Tatge, 2013). Previous studies suggested that changes in incubation temperature at the end of embryonic development can induce epigenetic temperature adaptation (Al-Rukibat et al, 2017;Al-Zghoul, Sukker, & Ababneh, 2019;Narinc, Erdogan, Tahtabicen, & Aksoy, 2016;Saleh, Tarkhan, & Al-Zghoul, 2020;Zaboli et al, 2017). This effect was also described as post-hatch heat conditioning (Zaboli et al, 2017).…”