The SpermSafe story

The Problem

The traditional sperm storage methods of chilling and cryopreservation can inflict severe damage to sperm cells, so much so, that cells have a reduced lifespan once warmed up, and fertility is markedly reduced. Now, researchers from the University of Newcastle have developed a solution to this problem; a 17°C sperm storage medium, SpermSafe™, that maintains sperm viability and fertility for at least 7 (and up to 14+) days, without inflicting cold shock.

The Research

Dr Zamira Gibb and Dr Aleona Swegen carried out extensive research to firstly understand how stallion sperm cells metabolise energy, and then to identify the nutrients, antioxidants, and storage conditions required for optimal longevity. During storage, sperm cells are actively metabolising, and in doing so, produce a great deal of harmful reactive oxygen species and waste products. Following repeated experimentation, these researchers devised the optimal formulation that works to neutralise these toxic by-products, thereby supporting sperm longevity. The result has been the development of a synthetic sperm medium that maintains cell motility, viability, and fertilising ability of cells up to 14 days. The first foal bred using the sperm extender was born on Christmas Day 2018, with many more on the ground to date.

The Benefits

As an alternative to traditional semen storage methods, SpermSafe is more cost-effective, less labour-intensive, and less invasive for mares―offering greater flexibility in insemination regimens. SpermSafe is free of any biological materials, such as egg or milk, thereby eliminating the biosecurity threat that accompanies international importation, and reducing the risk of processing delays at international borders. Furthermore, this protein-free formulation produces significantly less breeding-induced endometritis compared to AI with frozen semen.

The scientists

  • Dr Zamira Gibb

    ARC Future Fellow and Senior Lecturer in Reproduction

    Dr Zamira Gibb is an accomplished reproductive biologist and a leading expert in equine fertility. She holds a PhD in Veterinary Science and has dedicated her career to advancing our understanding of reproductive processes in animals, particularly horses. Dr Gibb's research focuses on improving fertility outcomes through innovative techniques in assisted reproduction and the study of oxidative stress in stallion sperm. She has published extensively in high-impact journals and is recognised for her contributions to veterinary and animal sciences. As a Research Fellow and Senior Lecturer at the University of Newcastle, Dr Gibb is passionate about mentoring the next generation of scientists and translating her research into practical applications for the equine industry.

  • Dr Aleona Swegen

    ARC DECRA Fellow

    Dr Aleona Swegen is a veterinarian and research fellow in animal fertility. She is passionate about using cutting edge, novel techniques in reproductive biology to benefit horses, livestock and endangered species, and developing new approaches to preserve fertility. Aleona holds a Bachelor of Veterinary Science from the University of Sydney (2010), and following several years’ work in clinical practice, obtained her PhD under Prof John Aitken at the PRC for Reproductive Science, University of Newcastle, Australia, focusing on the proteomics of stallion spermatozoa and equine embryos. After stints at the Smithsonian Conservation Biology Institute (USA) and University of Oxford (UK), she is back at Newcastle leading several projects in equine fertility, focusing on the effects of heat stress on fertility and offspring health, equine IVF and mechanisms of early pregnancy.

  • Distinguished Emeritus Professor John Aitken

    Professor John Aitken is a global expert on male fertility and sperm biology. With a career spanning over four decades, he has made significant contributions to our understanding of sperm function and the role of oxidative stress in infertility. Professor Aitken is a Fellow of the Australian Academy of Science and has received numerous accolades for his pioneering research, including the prestigious Carl G. Hartman Award.

The research

[1] Gibb, Z., Lambourne, S.R., and Aitken, R.J. (2014) The paradoxical relationship between stallion fertility and oxidative stress. Biology of Reproduction. 91 (3): p. 77.

[2] Gibb, Z., Lambourne, S.R., Curry, B.J., Hall, S.E., and Aitken, R.J. (2016) Aldehyde Dehydrogenase Plays a Pivotal Role in the Maintenance of Stallion Sperm Motility. Biology of Reproduction. 94 (6): p. 133.

[3] Swegen, A., Lambourne, S.R., Aitken, R.J., and Gibb, Z. (2016) Rosiglitazone Improves Stallion Sperm Motility, ATP Content, and Mitochondrial Function. Biology of Reproduction. 95 (5): p. 107.

[4] Gibb, Z., Lambourne, S.R., Quadrelli, J., Smith, N.D., and Aitken, R.J. (2015) L-Carnitine and Pyruvate Are ProsurvivalFactors During the Storage of Stallion Spermatozoa at Room Temperature. Biology of Reproduction. 93 (4): p. 104, 1-9-104, 1-9.

[5] Gibb, Z., Clulow, J. R., Aitken, R. J. & Swegen, A. First Publication to Describe a Protocol for the Liquid Storage of Stallion Spermatozoa for 7 Days. Journal of Equine Veterinary Science 66, 37-40 (2018). https://doi.org:https://doi.org/10.1016/j.jevs.2018.05.016

[6] Gibb, Z. et al. Storing stallion sperm in SpermSafe™ at 17°C may improve fertility by reducing mPTP formation. Journal of Equine Veterinary Science 125, 104589 (2023). https://doi.org:https://doi.org/10.1016/j.jevs.2023.104589

[7] Clulow, J., Swegen, A., Aitken, J. & Gibb, Z. Preliminary insemination trial to determine the fertility of stallion sperm stored for 3 and 7 days at 17ºC in a long term liquid storage medium. Clinical Theriogenology 11, 461 (2019). https://doi.org:10.58292/ct.v11.10220

[8] University of Newcastle, ‘Sperm extender the recipe for fertility success’ https://www.youtube.com/watch?v=UAB6BaLbYG4

Our collaborators

Our research and the development of SpermSafe would not be possible without the longstanding support of our partners and collaborators

Harness Racing Australia

EquiBreed UK

EquiBreed ART NZ