Poultry Production Department, Faculty of Agriculture, Ain Shams University, Shoubra El-Kheima, 11241, Cairo, Egypt.
Animal Production Department, National Research Centre, Dokki, 12622, Giza, Egypt.
J Therm Biol. 2023 Aug;116:103640. doi: 10.1016/j.jtherbio.2023.103640. Epub 2023 Jul 24.
Short Periods of Incubation During Egg Storage (SPIDES) approach improves chick quality and hatching rates. Also, embryonic thermal conditioning (TC) is a strategy for enhancing thermotolerance in avian species. Until now, evaluating the effect of either SPIDES or embryonic TC effects has only been separately conducted, so we hypothesized that combining TC and SPIDES may enhance the response of broilers to thermal stress. Eight hundred Ross broiler eggs were divided into two groups; the first one was kept under appropriate storage room conditions, S (control) The 2nd was subjected to SPIDES for 5 h at 37.8 C ± 0.1 three times at days 5, 10, and 15 (S) after egg collection respectively. On the 14th day of incubation (DOI) each of the two main groups was randomly divided into two equal subgroups; the control one was left under the appropriate incubation settings (TC) whereas the other received prenatal heat conditioning (TC) at 39.5 C ± 0.1 for 6 h/d from the 14th to the 18th embryonic day (E), resulting finally in four experimental subgroups (STC, STC, STC & STC). RESULTS: showed that SPIDES treatment improved the hatchability of the stored eggs by almost 20% compared to untreated eggs. A combination of SPIDES and TC (STC) increased significantly the levels of Immunoglobulin (IgG and IgM) production at hatch and heat-stressed birds. Our findings revealed that the hepatic heat shock proteins (hsp70, 90 A,90 B, 60 and hspA9), antioxidants-related genes (CAT, and SOD2), and NADPH4 were significantly downregulated in the thermally conditioned group that challenged with thermal stress conditions. As opposed to that, the SPIDES group showed a significant increase in hepatic heat shock proteins, antioxidants-related genes, and NADPH4 when subjected to thermal-stress conditions. In conclusion, the combination of SPIDES and TC has a positive effect on some pre and post-hatch traits of broiler chicks. Under heat stress challenge, thermal conditioning can modify the expression of antioxidant-related genes and Hsps, leading to the enhanced acquisition of thermotolerance as evidenced by lower expression of Hsps and NADPH4. While SPIDES does not have a significant role in thermotolerance acquisition.
短期储存期（SPIDES）方法可提高鸡胚质量和孵化率。此外，胚胎热调节（TC）是提高禽类耐热性的一种策略。到目前为止，评估 SPIDES 或胚胎 TC 效果的影响仅分别进行，因此我们假设将 TC 和 SPIDES 结合使用可能会增强肉鸡对热应激的反应。800 枚罗斯肉鸡种蛋被分为两组；第一组在适当的储存室条件下保存，S（对照组）；第二组在收集后第 5、10 和 15 天分别在 37.8°C ± 0.1 下进行 SPIDES 处理 5 小时，每天 3 次。在孵化的第 14 天（DOI），两个主要组的每一个都被随机分为两个相等的亚组；对照组保持在适当的孵化设置下（TC），而另一个从第 14 天到第 18 天胚胎日（E）每天接受产前热调节（TC）在 39.5°C ± 0.1 下 6 小时/天，最终得到四个实验组（STC、STC、STC 和 STC）。结果表明，与未经处理的鸡蛋相比，SPIDES 处理可将储存鸡蛋的孵化率提高近 20%。SPIDES 和 TC（STC）的组合可显著提高孵化时和受热应激鸟类的免疫球蛋白（IgG 和 IgM）的产生水平。我们的研究结果表明，在受到热应激条件挑战时，热调节组的肝脏热休克蛋白（hsp70、90A、90B、60 和 hspA9）、抗氧化相关基因（CAT 和 SOD2）和 NADPH4 显著下调。相比之下，SPIDES 组在受到热应激条件时，肝脏热休克蛋白、抗氧化相关基因和 NADPH4 显著增加。总之，SPIDES 和 TC 的组合对肉鸡雏鸡的一些孵化前和孵化后特征有积极影响。在热应激挑战下，热调节可以改变抗氧化相关基因和 Hsps 的表达，从而增强热耐受性的获得，表现为 Hsps 和 NADPH4 的表达降低。而 SPIDES 对获得热耐受性没有显著作用。
