048. FUNCTIONAL DIFFERENCES BETWEEN SEX-SORTED AND NON-SORTED SPERM

Abstract

The development and application of flow cytometric sorting for the pre-selection of sex has progressed at an increasing rate since the first report of live pre-sexed offspring of rabbits (2). The technique has been extended to production of pre-sexed offspring of numerous species and sorted bull semen is now widely available commercially around the world. Due to the stresses involved in the sex-sorting process, sex-sorted sperm may be functionally compromised in terms of reduced motility and viability, and their fertilising lifespan within the female reproductive tract may be reduced. Consequently, fertility in vivo may be compromised. However, improvements to the technology and a greater understanding of its biological impact on the sperm have facilitated recent developments in sheep, and we have demonstrated that sex-sorting is capable of selecting a functionally superior ram sperm population in terms of both in vitro and in vivo function. This has resulted in high fertility after intrauterine insemination of sex-sorted ram sperm (1). Unfortunately, to date, these results have not been matched in other species.