Artificial insemination keeps female crocs out of fray
SOME people may think artificial insemination of cattle is icky stuff - now give crocodile AI a go.
Central Queensland's resident croc farmer John Lever, of Koorana Crocodile Farm on the Capricorn Coast, is playing an integral role in a University of Queensland research project looking into the artificial insemination of
Crocs are unique in that the females can store sperm over seasons and then fertilise themselves at the appropriate time - one in particular at Koorana hadn't been with a male for two years when she released her eggs.
This is what inspired Mr Lever, who is a former cattle AI technician, to pursue the project.
"What a lovely thing, that you can inseminate at any time of the year and they can store the sperm and ovulate at any time of the year," Mr Lever said.
"I thought I'd love to give it a go, so I called Steve Johnston, a reproductive biologist at UQ's School of Agriculture and Food Sciences, and asked, 'Can you give this a go?' and he jumped on it."
And they soon discovered they were best to go back to basics.
"We started off by using electro-ejaculation but we found it's not necessary - it's invasive and can distress the animal," Mr Lever said.
"We drug it to relax them so that it's not going to be frightened, and then it's just a manual process of collecting the semen."
As much as we love our big males, we don't love some of them because some of them kill girls.
If the project is successful, it will be a great milestone for croc farmers because it will enable them to house as few males as possible.
"If we can hold a few males - even none - if you can get out in the wild then use that to inseminate females, it means you could theoretically have a breeding farm without any males," Mr Lever said.
"As much as we love our big males, we don't love some of them because some of them kill girls.
"When you've got a croc that kills a female, you've wasted 30 years of production.
"When the male produces sexual hormones, he becomes very territorial, so every female in his area belongs to him.
"We can't have great big lakes everywhere with one male and a couple of females.
"We've got to have smaller pens but we run into problems of females (not taking to it), then he chases and grabs and wrestles with the females and because they are smaller, they usually come off second-best."
And Mr Lever thinks it really isn't that different from breeding cattle.
"We can select certain characteristics that are beneficial, like passiveness," he said.
"It goes back to the way the scientists selected brahman for breeding - they looked for meat quality.
"We're looking for skin quality - it's not so different really. We're just farming wild animals for commercial purposes."
Dr Johnston, who was part of the team that announced the world's first koala baby born by AI in 1998, said AI would have more benefits than merely not housing male crocs.
"If we can collect semen safely from large male crocodiles in the wild, this will also strengthen genetic diversity," he said.