The world’s oldest semen still swimming strong

Wednesday, 20 February 2019

The world’s oldest frozen ram semen in existence is still swimming strong achieving high fertility rates when thawed and inseminated as part of the 2018 Balmoral Merino Sire Evaluation program.

Frozen in 1968 by Dr Steven Salamon of The University of Sydney, the 50-year-old semen comprised a pool of semen from four rams of Ledgworth, Merryville and Boonoke genetics, owned at the time by the Walker family of Ledgworth (and latterly Woolaroo), Yass.

Australian Wool Innovation General Manager for Research Dr Jane Littlejohn explained AWI’s predecessors, Australian Wool Research and Promotion Organisation (AWRAP), the Australian Wool Commission and Australian Wool Corporation co-funded much of the pioneering work into frozen semen and the laparoscopic insemination technology.

“Remarkably, pregnancy scanning results indicate that despite 50 years of storage the sperm are as fertile as the day the semen was frozen, with pregnancy and scanning rates no different to the overall average of all sires who were also artificially inseminated in the Balmoral program,” Dr Littlejohn highlighted.

“The high fertility of this semen demonstrates that long term frozen storage of sperm is safe and reliably preserves genetics for future use in the agriculture industry.

“This trial offers a remarkable opportunity to open a window to the industry’s past and in doing so also contemplate the future of sheep selection and genetics and what we might expect to see in 50 years’ time.

“Beyond insights into artificial breeding and semen freezing technology, use of this semen also stands to showcase 50 years of genetic progress of the Australian wool industry.

“Continued support from AWI aims for current research projects to build on this legacy and deliver the next generation of assisted reproductive technologies for the sheep industry.”

For researchers at The University of Sydney, looking down the microscope at sperm cells swimming for the first time in 50 years is a window to their history of sheep reproduction research and a reminder of the remarkable discoveries their predecessors made to enable the artificial insemination of sheep.

The progeny will be on display at the Balmoral Merino Sire Evaluation Field Day on Friday 22 February 2019 at ‘Kooringal’, 2115 Coleraine-Edenhope Road, Coleraine, Victoria.