Beyond the yolk – A replacement for animal-based product semen extenders

Bull semen export is a multi-billion-dollar industry in the United States. This proposal addresses topic area priority 8.3 Animal Production and Protection FY 2025 improvement of livestock production efficiency; directly addressing the increase in export of genetics without inadvertent animal disease co-transport, thereby improving the stronghold of U.S. genetics worldwide.The most reliable semen extenders used for sperm cryopreservation utilizes animal products such as egg yolks and whole milk mixed combined with salt and sugar buffered solutions that provide an energy source and some cryopreservation protection. The use of these animal products presents an issue in the export market of semen where there is a need to reduce dissemination of disease potentially contained in these animal products such as avian influenza and other pathogens to livestock. Alternatives to animal products for sperm cryopreservation includes soy lecithin in a buffered solution; however, such replacements lack the full benefits provided by egg yolk and milk which maintain sperm quality.To address the deficiencies in current animal-based semen extenders used for cryopreservation, Phase I focuses on the development of plant-based replacement that provides the same protective benefits of egg yolk or milk by testing sources of plant extracts in combination. The combinations will be assessed for similarity to egg yolk, whole milk, and impacts on post-thaw sperm quality.The development of the proposed technology will have direct impact on the U.S. export market of bull semen. This product also has economic upside as research can be rapidly applied to other species such as pigs, sheep, and goats.