Vet World   Vol.16   May-2023  Article-4

Effects of embryonic thermal manipulation on the immune response to post-hatch Escherichia coli challenge in broiler chicken

Background and Aim: Thermal manipulation (TM), exposure to mild heat shock during embryogenesis, which is a critical developmental period of broiler chickens, improves tissue stability, oxidative stress response, and immune response during heat stress. Thermal manipulation could be more cost-effective than other methods to boost the immune response. This study aimed to evaluate the impact of TM during embryogenesis, concomitant with an Escherichia coli challenge, on body weight (BW), body temperature (Tb), and splenic mRNA expression of cytokines (Interleukin [IL]-1β, IL-2, IL-6, IL-8, IL-12, IL-15, IL-16, IL-18, and interferon [IFN]-γ) in poultry.

Materials and Methods: A total of 740 fertile eggs were procured from a certified Ross broiler breeder. The eggs were divided into two incubation groups: the control and TM groups. The eggs in the control group were kept at 37.8°C air temperature and 56% relative humidity (RH) during incubation; eggs of the TM group were incubated under standard conditions, except for embryonic days 10–18, during which they were incubated at 39°C and 65% RH for 18 h daily. On the 7th day of incubation, eggs with dead embryos were excluded. After hatching was complete, each group was further subdivided into saline-treated or E. coli-challenged groups. The E. coli (serotype 078 with the dose of 1.5 × 105 colony-forming unit/mL) challenge was performed when the birds were 20 days old. Body weight and Tb measurements were taken on post-hatch days 20, 21, 23, and 25. Splenic mRNA expression of cytokines (IL-1β, IL-2, IL-6, IL-8, IL-12, IL-15, IL-16, IL-18, and IFN-γ) was analyzed by real-time quantitative polymerase chain reaction.

Results: Following the E. coli challenge, the TM-treated group’s body performance parameters (BW and Tb) were significantly increased compared with the control group. Body weight was higher in the TM group than in the control group (p < 0.05); Tb was lower in the TM group than in the control group (p < 0.05). The mRNA levels of IL and IFN-γ were more stable and moderately induced in the TM group compared with the control group. Thermal manipulation altered the basal mRNA levels of ILs and IFN-γ and changed their expression dynamics after the E. coli challenge.

Conclusion: Thermal manipulation during embryogenesis could boost the immune system response to E. coli. Keywords: broiler, challenge, Escherichia coli, immune response, incubation, thermal manipulation.

Keywords: broiler, challenge, Escherichia coli, immune response, incubation, thermal manipulation.

How to cite this article: Al-Zghoul MB, Jaradat ZW, Ababneh MM, Okour MZ, Saleh KMM, Alkofahi A, and Alboom MH (2023) Effects of embryonic thermal manipulation on the immune response to post-hatch

Received: 02-01-2023  Accepted: 27-03-2023     Published online: 07-05-2023

Corresponding author:    E-mail: alzghoul@just.edu.jo

DOI: 10.14202/vetworld.2023.918-928

Copyright: Al-Zghoul, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.