News & Opinion | March 21, 2019 2:00 pm

The World’s Oldest Sperm Was Used To Make A Baby Lamb

The specimen was frozen for 50 years.

Researchers in Australia thawed out 50-year-old sperm from a merino sheep and used it artificially inseminate almost 60 ewes. As a result 34 of them went on to give birth to baby lambs.

The pregnancy rate for sperm that’s been frozen for just one year is about 59%– when using the 50-year-old sperm, the world’s oldest, scientist found a 61% rate of pregnancy. The sperm had been stored at subzero temps.

“When we first thawed out the semen to test its quality (motility, viability, DNA integrity) we were very excited (and a little relieved!) to see that 50 years of storage at -196°C had had seemingly no ill effects on the health of the sperm,” Simon De Graaf, from the Sydney Institute of Agriculture and School of Life and Environmental Sciences at the University of Sydney told CNN. “That gave us confidence that if we used the sperm for artificial insemination it should still be fertile.”

The baby lambs seem to be doing well and are in good health. They even resemble their father merino sheep, which has slightly different characteristics today than it did 50-plus years ago. Researchers hope to be able to apply their findings to conservation efforts of endangered species.