Transcriptomic responses of in ovo delivered bioactive substances in heat-stressed broiler chickens

家禽是全球消费量最大的动物蛋白之一;因此，家禽业目前维持着数十亿人的粮食安全。尽管家禽业的重要性，家禽的福利和性能正在受到有关使用抗生素的环境和监管因素的损害。热应激（HS）被明确认为是对家禽业产生负面影响的“主要环境因素”。当体内产生的热量超过其消散能力，动物无法摆脱多余的热量时，就会发生HS。家禽缺乏汗腺，由于选择快速生长而具有增加的代谢率;因此它们更容易受到HS的影响，这对家禽业造成重大的经济损失。HS对家禽业的经济影响每年损失高达1.65亿美元。据报道，几种生物活性物质具有HS缓解和抗生素替代特性。然而，生物活性物质递送的常规途径，即，通过饲料或水，限制其功效。通过卵内途径递送这些物质可能有助于克服传统递送途径的局限性，并增强其HS缓解和抗生素替代能力。因此，本研究拟利用分子生物学技术来评估肉鸡对模拟夏季高温的反应。还将确定卵内递送的生物活性物质（益生菌、叶酸和精油）的HS缓解潜力。这项研究的结果可以帮助解决全球家禽业面临的两个关键挑战，找到抗生素和HS缓解的有效替代品。这项研究将确保肉鸡肠道健康的最佳发展，从而消除使用抗生素的必要性。与美国阿肯色州大学家禽科学卓越中心的鸟类内分泌学和分子遗传学教授合作，我们将使用基因组学和转录组学工具确定免疫和肠道屏障相关的基因表达。博士学位学生将接受双方参与研究人员的培训。

Poultry constitutes one of the most consumed animal proteins globally; thus, the poultry industry currently sustains the food security of billions of people. Despite the importance of the poultry industry, the welfare and performance of poultry birds are being impaired by environmental and regulatory factors regarding the use of antibiotics. Heat stress (HS) has explicitly been regarded as "the main environmental factor" negatively impacting the poultry sector. HS occurs when the heat generated in the body surpasses its dissipation ability and the animal becomes incapable of getting rid of excess heat. Poultry lacks sweat glands and has an increased metabolic rate due to selection for rapid growth; hence they are more vulnerable to HS, which causes significant economic losses to the poultry industry. The economic impact of HS on the poultry industry is up to $165 million in annual losses. Several bioactive substances have been reported to have HS mitigative and antibiotic replacement properties. However, the conventional routes of bioactive substance delivery, i.e., via the feed or water, limit their efficacy. Delivering these substances via the in ovo route might help overcome the limitations of the conventional delivery routes and enhance their HS mitigating and antibiotic replacement capacities. Therefore, this study intends to utilize molecular biological techniques to evaluate broiler chickens' response to a mimicked summer heatwave. The HS mitigating potential of in ovo delivered bioactive substances (probiotics, folic acid, and essential oil) will also be determined. Outcomes from this study could help solve two critical challenges facing the global poultry industry, finding an effective alternative to antibiotics and HS mitigation. This research will ensure optimal gut health development in broiler chickens, hence dismissing the need for antibiotic use. In collaboration with a Professor of Avian Endocrinology and Molecular Genetics, at the Center of Excellence for Poultry Science, University of Arkansas, USA, we will determine the immune and intestinal barrier-related gene expression, using genomic and transcriptomic tools. A Ph.D. student will be trained by both participating researchers.