The contribution of somatic cells to non-rodent male germ cell transplantation success has not been well established due to lack of cell-type specific markers to distinguish donor from host cells. In the present study, we first screened antibodies and a lectin to identify markers suitable for unequivocal distinction between germ and Sertoli cells in bovine compared to mouse testes. Anti-vimentin and the DBA lectin detected only bovine Sertoli cells and spermatogonia, respectively; anti-NONO and anti-GCNA1 detected only mouse Sertoli and germ cells, respectively. The outcome of transplanting bovine testis cells into nude mouse testes was then studied using these markers. Our results clearly showed immature bovine Sertoli cells survive and colonize mouse testes within 2.5 months after transplantation, and donor Sertoli cell-composed tubular structures formed adjacent to murine tubules within the host mouse testis. Bovine germ cell colonization and survival in mouse testis after transplantation were confirmed, but this was restricted to areas of bovine Sertoli cell colonization. In addition, ectopic grafts of intact bovine testis tissue and cell aggregates from hanging drop cultures were placed under the back skin and testis capsule of nude mice. Bovine Sertoli cells in ectopic grafts and aggregates were able to form tubular structures and some bovine germ cells were observed around 2 months after implantation. This study therefore identifies a practical strategy to assess the outcome of testicular cell transplantation using different antibodies and a lectin to distinguish bovine cells from mouse cells. It identifies an approach which can readily be adapted to study other non-rodent species.