Limited vertical transmission of microbiomes occurs through the chorioallantoic membrane, influencing the development of the intestine, metabolic pathways, and immune response in broiler embryos

The chicken chorioallantoic membrane (CAM) is a highly vascularized extraembryonic membrane, a simple, rapid, and economical model that permits the examination of tissue grafts, tumor proliferation and metastasis, drug delivery, toxicological assessment, and angiogenic and anti-angiogenic compounds. However, its microbial characterization is still unknown. The gut microbiota constitutes a complex ecological community and is extensively acknowledged in various research domains; however, the relationship between gut microbiota and embryonic development in chickens remains poorly understood. Embryonic thermal manipulation (TM) represents a promising approach for sustainable broiler production.