Effects of heat stress on the immune responses of chickens subjected to thermal manipulation in the pre-hatch period

Abstract

Heat stress affects the performance of poultry species and also induces immunosuppression. Chickens can be treated by thermal conditioning to have better heat stress tolerance. Our purpose was to determine the effect of acute heat stress on the immune response, i.e. antibody production against Newcastle disease virus (NDV) and change in the proportion of leukocyte components, in chicks subjected to prenatal heat conditioning. Eighty as-hatched broiler chicks from the same parent stock were used: control (40 chicks incubated at 36.7 °C from days 18–20 of embryonic life) and thermally manipulated (TM) (40 chicks incubated at 38.4 °C from day 18–20 of embryonic life; 4 h/day). The chickens were exposed to heat stress: at day 19 (31 °C/8 h) and at day 35 (32 °C/10 h). The first heat stress (day 19) decreased the lymphocyte counts and significantly increased the heterophil counts (P < 0.05) in both treatments (from 34.25 to 55% in the controls and from 37 to 60.06% in the TM chicks). The second heat stress (day 35) did not alter the heterophil and lymphocyte profiles of the chickens. Before the heat stress, all of the chickens (control and TM) presented the same positive antibody titres to NDV vaccination. After the first heat stress, 50% of the control samples and 40% of samples from the TM chickens were negative. After the second heat stress, 80% of the TM samples were negative.

Impact of Temperature Changing During Incubation Process on Hatching and Chick’s Quality Traits of Broiler Breeder Eggs

“…Monitoring Hatching time from table (1) revealed that through 40 hours (470 to 510 h) there were no significant differences between treatments in 4 first period (from 470 to 502 h), whereas, the significant differences occurs at last period (502 to 510 h), most of chicks in control group were hatched (60.83%), while less chicks had hatched (19.79%) in 2 nd treatment which eggs subjected to changing in temperature at 10 th day of incubation. The results were in line with [55] who use changing in temperature (39.5 1C every 12 h during embryonic days E7-E16), they referred that there were no significant differences in hatching time from 470 onward between treatments group, in contrast to [56] who noticed that use changing in temperature (39.5° C, from 7−16 d for 12 h per d) leading prolong hatching time in treated group and shorter spread of hatch in control group [57].…”

A Statistical Expert on the Margin: The Career Trajectory of József Kőrösy

“…58 K r sy was a vaccinationist. He firml ybe li e v edth a ts mall po xv acc i nationw ouldreducetheeff ectsoffutureepidemics .Hisgoalw astopro v e the protective power of vaccination through statistical means, and hence its utility,withtheaidof"relativeintensity".Hepresentedthemethodinacom prehensive study at the 11th International Medical Congress in Washington in 1887 59 andthenpublisheditinaseparatevolumein1889, 60 thereby opening a critical debate amongst medical experts. K r systudiedtheprotectivepower of vaccination in quantitative terms.…”

Effect of heat stress on the hypothalamic expression profile of water homeostasis‐associated genes in low‐ and high‐water efficient chicken lines

“…Of particular interest, and due to their elevated core body temperature compared to mammals (~41°C vs. 37°C), high metabolic rate, feather covering, and lack of sweat glands, chickens (meat and egg types) are very sensitive to high environmental temperatures (Perini, Cendron, Rovelli, Castellini, & Cassandro, 2021 ). The detrimental effects of high environmental temperature on feed intake (Abdelli et al., 2021 ; Brugaletta et al., 2021 ; Tabler et al., 2020 ), growth (He et al., 2018 ; Liu et al., 2020 ; Wasti, Sah, & Mishra, 2020 ), welfare (Sesay, 2022 ; Shields, 2015 ), stress (Greene et al., 2022 ; Lin et al., 2006 ; Mahmoud & Edens, 2003 ), immune system (Jahanian & Rasouli, 2015 ; Liu et al., 2022 ; Molnar, Korosi, Balazs, & Gaspardy, 2021 ; Monson et al., 2018 ), and meat and egg quality (Dai et al., 2009 ; Dai et al., 2012 ; Leishman et al., 2021 ; Maynard et al., 2023 ; Zaboli et al., 2019 ) are well documented. Together, these effects consequently result in significant and heavy economic losses to the industry worldwide (Raspoet & Wang, 2022 ; St Pierre, Cabanov, & Schnitkey, 2003 ), in addition to the add capital investment such as fans, cooler pads, and water sprinklers.…”