Australian researchers are hoping to lift the low success rate of artificial insemination in sheep.
Artificial insemination or AI is common in beef and dairy cattle - but it is not so common in sheep as it is not as successful, with only about a 30 per cent pregnancy rate when frozen semen is used.
Researchers at the University of Queensland want to figure out what is happening and are running some tests on a small mob of sheep.
Lecturer in Veterinary Reproduction Dr Taylor Pini said there was something about the anatomy of the sheep’s cervix which meant frozen semen was less successful.
“We’ve taken [samples] of cervical tissue from sheep that would be in the right stage to be bred and exposed it to either fresh or frozen sperm in vitro, so in a lab setting.
“What we’re trying to do is look at how that cervical tissue responds differently to fresh and frozen semen because we know that fresh semen is very capable of getting through the sheep’s cervix, so we need to understand what goes wrong when we freeze sperm.
“What goes wrong with that interaction between cervical cells and the frozen sperm.”
Pini said there was a huge demand from the sheep industry for artificial insemination as it could improve wool and meat yields and enhance animal welfare.
Only around 5 per cent of sheep in Australia are bred using artificial insemination, compared to the Australian dairy industry which boasts rates of 85 per cent.
“In the dairy industry, artificial insemination has allowed for rapid genetic improvements in cows while the sheep industry has been restricted to much slower progress through natural mating,” Pini said.
Dr Taylor Pini said there's huge demand from the sheep industry for artificial insemination. Photo / Supplied / University of Queensland
“Alongside improvements in traits like wool and meat yields, artificial insemination would also allow for the selection of animals that have a reduced climate impact and an enhanced capacity to cope with the changing climate.”
Pini said more reliable artificial insemination in sheep would lead to rapid production gains as producers gain access to elite male genetics without the biosecurity risks involved in moving rams.
“In the New Zealand context, we might want to import sheep genetics from Australia to New Zealand or vice versa and realistically, the only way that we can do that is using frozen semen.
“So by being able to improve the pregnancy rate coming from artificial insemination using frozen semen it essentially means that we’re opening the door for producers to use and import really great genetics that they really only have access to with frozen semen.”
Dr Pini said the results of the artificial insemination research should be published in a year.
