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

家禽是全球消费最多的动物蛋白之一；因此，家禽业目前维持着数十亿人的粮食安全。尽管家禽业很重要，但家禽的福利和性能正受到有关使用抗生素的环境和监管因素的影响。热应激(HS)已明确被视为对家禽养殖业产生负面影响的“主要环境因素”。当体内产生的热量超过了它的散热能力，动物就无法排出多余的热量时，就会发生HS。家禽缺乏汗腺，由于选择快速生长，代谢率增加；因此，它们更容易受到HS的影响，这给家禽业造成了重大的经济损失。HS对家禽业的经济影响每年高达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，传统的生物活性物质输送途径，即通过饲料或水，限制了它们的效果。通过体内途径输送这些物质可能有助于克服传统输送途径的局限性，并增强其缓解HS和抗生素替代的能力。因此，本研究打算利用分子生物学技术来评估肉鸡对模拟夏季热浪的反应。还将确定体内释放的生物活性物质(益生菌、叶酸和精油)对HS的缓解潜力。这项研究的结果可能有助于解决全球家禽业面临的两个关键挑战，即找到抗生素和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需要。与美国阿肯色大学禽类科学卓越中心的禽类内分泌学和分子遗传学教授合作，我们将使用基因组和转录转录工具确定免疫和肠道屏障相关基因的表达。一名博士生将接受双方参与的研究人员的培训。

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.