All is not lost if a valuable animal dies on the farm, thanks to a new technique to extract viable semen within 48 hours.
The team at Canadian Animal Genetic Resources in Saskatoon has received the scrotums of dead animals to salvage viable sperm cells and produce another generation of cattle, goats, sheep, horses or pigs.
“We tried to develop tools that if a precious resource is lost due to death that we could not reach in time, at least they can send us the scrotum,” said Dr. Carl Lessard, head of the program run through Agriculture Canada.
This can be done for rare breeds or valuable animals that died suddenly.
Retrievable sperm cells could be available for use by the animal’s owner or storage in the gene bank in Saskatoon if the scrotum is packed correctly and received within 48 hours following death or castration.
Lessard suggests cutting off the scrotum from the dead animal, draining the blood and packing below room temperature in a resealable plastic bags with absorbent paper to avoid spills during transit via courier.
A Styrofoam box is ideal with an ice pack on the bottom and about an inch of protection to avoid freezing.
“We do not want it very cold — below 18 C — because it will start to damage the cells,” he said.
“The scrotum itself is a good container to isolate the testicles and the epididymis that we need to retrieve the mature sperm,” he said.
Once it arrives, laboratory staff can peel the scrotum to reveal the testes and epididymis, where mature sperm cells can be collected.
The quality is assessed and then the collection is frozen following standard procedures.
The volume of semen varies by age and species of animal.
The semen may not have all the same protective proteins present during an ejaculate, so rather than placing 25 million sperm in a regular straw, they may double that to make sure there is a good ratio of motile sperm cells afterward.
“If it is motile, it should be able to fertilize,” Lessard said.
Literature reviews show conception using the rescued cells may be lower than a normal collection of sperm cells. He has done some tests with in vitro fertilization, but budget constraints prevented further research.
“If the goal is to produce progeny, we just have to use a good amount of sperm cells when we do the artificial insemination,” he said.
The centre in Saskatoon maintains a semen bank, which includes rare breeds.
Producers may eventually want to rejuvenate some breeds because of increased inbreeding among the mainstream breeds and the loss of some qualities.
Last year CAGR received scrotums from Guernsey and Lynch Lineback bulls, Shropshire and Nubian goats, a Clydesdale stallion and Berkshire pigs, which resulted in 650 doses of viable sperm. Three hundred doses were returned to producers for owner-use only.
The technology to collect semen has been around since the 1950s, and older samples of about 50 years of age have proven to still be viable and achieved successful pregnancies.
Bovine sperm cells seem to have good longevity but more work is needed on cryopreservation of sperm cells from pigs, said Lessard.