While exposure of spermatozoa to seminal plasma is not an absolute requirement for their subsequent fertility, a growing body of literature has demonstrated the highly varied role of this fluid in reproduction. Our studies have focused on understanding the physiological roles of seminal plasma in sheep, with the ultimate goal of utilising seminal plasma to improve outcomes of artificial insemination with cryopreserved semen. Our insemination trials demonstrated that while seminal plasma does not alter basic semen parameters, it is a key component driving successful cervical transit of ram spermatozoa. Employing proteomics, we showed that seminal plasma and its extracellular vesicles deliver a limited protein cargo to ram spermatozoa, rather than introducing a wide variety of novel proteins. Using flow cytometry and in-vitro binding assays, we also demonstrated that seminal plasma exposure alters the sperm glycocalyx and interferes with sperm-neutrophil binding, potentially contributing to sperm survival within the female tract. Based on our proteomic findings, we subsequently focused on the highly abundant seminal plasma Binder of Sperm Proteins, exploring their physiological roles in ram sperm capacitation, including cholesterol efflux, and their potential application in minimising sub-lethal sperm freezing damage. Further work will focus on using a combination of complementary, physiologically relevant seminal plasma proteins to enhance the field fertility of cryopreserved ram semen.