During mammalian fertilization, germ cell-specific hyaluronidases, such as sperm adhesion molecule 1 (SPAM1) and hyaluronoglucosaminidase 5 (Hyal5), are important for the dispersal of the cumulus mass. In this study, we demonstrated that bull Hyal5 is a single copy gene on chromosome 4 that is expressed specifically in the testis. In addition, we expressed recombinant bull SPAM1 and Hyal5 in human embryonic kidney 293T cells and showed that these enzymes possessed hyaluronidase activity. We also demonstrated that a polyclonal antibody against bull sperm hyaluronidase inhibits sperm-egg interactions in an in vitro fertilization (IVF) assay. Our results suggested that bull Hyal5 may have a critical role in bull fertilization.