Table1_Exposure to a Virtual Environment Induces Biological and Microbiota Changes in Onset-of-Lay Hens.XLS

Increasing demand for cage-free eggs arises from goals to provide hens with better welfare, particularly in terms of natural behavior. However, most laying hens are kept in conventional cages, and cage-free systems can present challenges, such as injuries, floor eggs, and bacterial infections. We proposed using virtual reality (VR) as a feasible means for combining the positive attributes of natural environments while mitigating health risks. To our knowledge, no animal study has provided evidence that VR can trigger biological changes to improve animal health and well-being nor whether VR can affect the gut microbiota. In this study, we used VR technology to simulate a natural environment in laying hen housing. Early-lay White Leghorn hens were placed in pens with (VR) or without (CON) video projections displaying free-range chickens interacting with indoor and outdoor environmental features over 5 days. Using in vitro blood bactericidal assays, VR hens exhibited higher resistance against avian pathogenic Escherichia coli versus CON (p < 0.05), which was positively associated with corticosterone levels (p < 0.01). Analyzing intestinal neurochemicals via ultra-high pressure liquid chromatography, salsolinol was the only neurochemical metabolite affected by VR, being greater in CON ileal content (p < 0.0001), in VR ileal mucus (p < 0.01), and in VR ceca tissue (p < 0.05). Using 16S rRNA sequencing and QIIME2 analyses, no differences in alpha nor beta diversity were determined between groups. Although several genera (Megamonas, Ruminococcus, Slackia) were reduced in VR hens versus CON, Mucispirillum schaedleri (member of Deferribacteres Phylum) was the only taxon increased in VR hens, being elevated in ileal mucus (p < 0.05). Lastly, using the QIIME2 plugin mmvec to map microbe-metabolite co-occurrences, we identified several positive relationships between bacterial phyla and neurochemical metabolites, notably finding dopamine and salsolinol levels were related to Deferribacteres and Tenericutes levels. In conclusion, we found that several biological parameters were influenced by VR treatment in hens, suggesting that VR can be used to improve host resistance to pathogens and gut health in poultry.

对笼养鸡蛋需求的日益增长源于为鸡提供更佳福利的目标，特别是在自然行为方面。然而，大多数产蛋鸡仍被饲养在传统的笼子中，而免笼系统可能带来诸如受伤、地蛋和细菌感染等挑战。我们提出利用虚拟现实（VR）作为一种可行的手段，将自然环境的有益特性与降低健康风险相结合。据我们所知，尚无动物研究提供证据表明VR能够触发生物学变化以改善动物的健康与福祉，亦无证据表明VR能够影响肠道微生物群。在本研究中，我们运用VR技术模拟了产蛋鸡舍中的自然环境。将早期产蛋的白来亨鸡放置于装有（VR）或未装（CON）视频投影的围栏中，这些投影显示散养鸡与室内外环境特征的互动，持续5天。通过体外血液杀菌实验，VR组的鸡对禽源致病性大肠杆菌的抵抗力高于CON组（p < 0.05），且这种抵抗力与皮质酮水平呈正相关（p < 0.01）。通过超高压液相色谱分析肠道神经化学物质，发现只有salsolinol这种神经化学代谢物受到VR的影响，其在CON回肠内容物（p < 0.0001）、VR回肠粘液（p < 0.01）和VR盲肠组织中（p < 0.05）含量更高。使用16S rRNA测序和QIIME2分析，未在组间发现alpha或beta多样性的差异。尽管在VR组中与CON组相比，某些属（如Megamonas、Ruminococcus、Slackia）的数量减少，但Mucispirillum schaedleri（属于Deferribacteres门）是唯一在VR组中数量增加的物种，其在回肠粘液中含量升高（p < 0.05）。最后，使用QIIME2插件mmvec绘制微生物-代谢物共现图，我们发现细菌门与神经化学代谢物之间存在多种正相关关系，特别是发现多巴胺和salsolinol水平与Deferribacteres和Tenericutes水平相关。总之，我们发现VR处理对鸡的多个生物学参数产生了影响，这表明VR可用于提高宿主对病原体的抵抗力和家禽的肠道健康。