WHAT'S happening in the artificial sheep breeding space was the major topic of discussion at the Stud Merino Breeders' Association of WA annual general meeting and sundowner in Perth recently.
Speaking at last week's event University of Sydney associate professor Simon De Graaf said there was a lot of research currently being undertaken in the sheep artificial breeding space.
"The projects are trying to push forward reproductive technologies and include looking at using frozen semen in cervical AI, sexed semen, sensing technologies and semen standards.
"The end goal of these projects is to provide producers with more options for use and improve the overall quality of breeding programs."
Professor De Graaf said cervical AI was old technology which still had benefits, especially when it came to animal welfare but there were problems when it came to using frozen semen with cervical AI.
"We have just completed a five-year research project to investigate what the story was with the frozen sperm, why it can't get through the tract and to see if you can rescue that ability," he said.
Professor De Graaf said the project achieved pretty much all of its objectives but it didn't solve the problem completely in terms of being able to get frozen semen through the cervix.
"We didn't absolutely solve the problem but we did find some interesting things, which are worth working further on," he said.
These findings included the freeze-ability of semen varied between rams and as a result there is now the potential to test to see if an animal's sperm will freeze well.
Professor De Graaf said the research found seminal plasma was the key to sperm getting through the cervix and they identified the proteins responsible for it, including binder of sperm protein (BSP).
"We found if the sperm has been exposed to the specific protein, it has like a cloak of invisibility and it can't just waltz through the cervix," he said.
"These results potentially mean you could utilise the protein and add it to sperm, so cervical AI could be performed with frozen semen and get the same pregnancy rates as if you had done laparoscopic AI, but we still need to test this theory."
Professor De Graaf said while they hadn't fully solved the problem of using frozen semen in cervical AI, they now know a lot more on the topic than they did five years ago.
"The project has also helped build research capacity in this space and the papers from it have been cited overseas and as a result the EU is pouring millions of Euros into sheep artificial breeding research," he said.
"It has kicked off a global push of research into this area."
When it comes to sexed semen professor De Graaf said it was easy to split male and female semen, likening it to drafting sheep.
"Each sperm is encased in a single droplet of fluid and has a positive or negative charge on it, depending if it is male or female," he said.
"It comes down through the machine and then the two electrostatic gates push the semen one way or the other depending on the charge, just like drafting sheep, and the semen is collected into tubes and you can do what you like."
The process is 90 per cent of accurate and research has shown fresh semen produces better results than frozen semen.
Professor De Graaf said in a trial conducted early last year they got up to a 70pc pregnancy rate using fresh sexed semen as long as enough sperm was used which was better than trials they had done with frozen semen.
"As a result of the work done in this area in Australia on sexed semen the process has now been commercialised in the United States and you can now buy sexed sheep semen there and you can also buy it in Australia if you speak to your artificial breeding centre," he said.
Professor De Graaf rounded out his presentation by talking about the most recently funded projects in the artificial sheep breeding space - semen standards and sensing technologies.
He said currently there was no universal semen standard for the sheep industry.
"We did a survey of all artificial breeding centres around Australia a couple of years ago and it became very apparent everyone had a different idea on what the actual pass for semen is," he said.
"Therefore it means if there is no standards, male factor infertility in certain places can become more uncontrolled.
"We are not trying to say every problem within an artificial breeding program is due to a problem with the semen, because there is an awful lot of other stuff that can go wrong.
"It may be a very small component and by having suitable standards that are accepted across the board hopefully it will reduce the number of times male factor infertility is the issue."
At the moment what is done within semen evaluation is to check for three things - how many sperm there are, whether or not they're motile and the morphology.
Professor De Graaf said this research would take the previous parameters of morphology, motility and concentration and link them through to fertility.
"A project like this has never been done in sheep before but we are going to change that over the course of the next two years," he said.
"The plan for the project is to utilise the sire evaluation sites in which 13,000 ewes are inseminated around Australia every year with 100 different sires.
"For the project we intend to take three, four or five straws of every ejaculate which is inseminated at all of the different sites, run all the tests on the semen and correlate them to the fertility outcomes so we can figure out what the minimum standards should be for semen."
In terms of the sensing technologies professor De Graaf said they would look at using the Smart Tag developed by Australian Wool Innovations for reproduction applications.
