Terminologies for the pre-attachment bovine embryo

There are numerous publications regarding bovine embryos, ranging from descriptions of their appearance and development to emerging techniques in the field of assisted reproductive technology (ART). Concurrently, several specialized terms have been developed to describe the bovine embryo. Many of these terms are simple, some are difficult to understand and use, and others are antiquated and may not be scientifically accurate. For example, use of terms such as syngamy, conception rate, implantation and embryo resorption should be revisited. This review presents a brief overview of current knowledge regarding the pre-attachment period of the bovine embryo and attempts to define the terms. In this process, conventional terminology is presented, and contemporary and novel terms are proposed from a biological perspective.