Livestock Blastoids: In Vitro Blastocyst Models for Embryogenesis and Reproductive Technologies

Understanding early embryogenesis in livestock remains a persistent bottleneck in both reproductive biology and animal breeding. Work in domestic species has long been limited by restricted access to embryos, ethical considerations, and the complexity of peri-implantation development, making mechanistic studies difficult. Recent advances in stem cell biology are beginning to shift this. Blastocyst-like structures, or blastoids, now offer a practical way to model early development in vitro. Blastoids capture key features of natural blastocysts, including overall structure, lineage composition, and gene expression patterns, while being far more accessible experimentally. In livestock species, especially cattle and pigs, blastoid models are starting to gain traction. Livestock blastoids provide a tractable system to study lineage specification, epiblast-extraembryonic interactions, and early conceptus development. They also open the door to improving assisted reproductive technologies by enabling controlled, scalable experimentation that is not feasible with embryos alone. In this review, we summarize recent advances in the generation of livestock blastoids and discuss how these systems can be used to study early development across livestock species and to inform next-generation reproductive technologies. We highlight current limitations and outline key challenges ahead, including how blastoid models can be combined with genome editing, stem cell engineering and related embryo-based approaches to improve reproductive efficiency in domestic animals.