This research is designed to provide alternative processing and storage procedures for bull semen for use in artificial insemination and other reproductive technologies. Modifications to conventional semen storage procedure are useful for alternative semen processing such as "sexed semen" and for salvaging semen from genetically superior sires that may have marginal semen quality or fertility. These methods have broad application throughout the U.S. and other countries and may be extended to other domestic, companion, and wildlife species.

Advantages of artificial insemination have progressed beyond genetic improvement, disease control, and husbandry issues to implementation of advanced technologies such as "sexed" and motility enriched semen. These technologies require procedural steps that have not been optimized for use in conventional semen processing and storage.

We are attempting to optimize media for holding fresh, diluted, but unfrozen bull semen to additional procedural steps and/or shipping prior to cryopreservation. Factors we are evaluating in media preparation include buffers, antioxidants, egg yolk composition as well as content, dilution rate, holding temperature, and other factors that impact the viability of ejaculated bull sperm. We have completed several experiments evaluating these factors primarily with unfrozen semen and are currently using the optimal media from these experiments to evaluate the impact on frozen-thawed semen.

The immediate impact of these procedures will be with procedures to eliminate dead or dying sperm from bulls with poor semen quality or fertility so that the resulting population is enriched in normal, motile sperm with acceptable fertility from selected, high demand sires. Additionally, semen processed in these media can be collected at sites where facilities and equipment for cryopreservation are unavailable, then shipped to an appropriate semen processing laboratory. These procedures may also enhance efforts to sort X- and Y-chromosome bearing sperm prior to packaging and freezing the sorted sperm by improving the viability of sperm during the sorting process. Overall, these methods should improve the semen quality and fertility of genetically superior dairy sires used for artificial insemination in New York and elsewhere.

Unrestricted funds

Genex/CRI, Inc.