Ruminating on Bovine Implantation: Its Importance in Fertility, Food Production, Conservation, and Health.

Implantation in cattle is a key developmental checkpoint for pregnancy success. It involves careful spatiotemporal changes to the transcriptional landscape of the endometrium, with the heterogeneous nature of the endometrium increasing the complexity of understanding of the mechanism involved. Implantation is impacted by the developmental competency of the embryo, use of assisted reproductive technologies, and the environment in which this process occurs. We identify the factors that most impact the implantation process in cattle and highlight how it differs with that in other placental mammals. We propose the major areas that lack evidence are the mechanism(s) by which implantation itself occurs and how different stressors alter this process. Our understanding is hindered by a lack of appropriate in vitro models; however, development of novel 3D tools and available data sets will further elucidate the implantation process. Perhaps more importantly, this will develop methods to mitigate against these stressors to improve implantation success and offspring health.