dave r and thurlow s&x trip to tassie

A two-headed calf has amazed cattle farmers in Tasmania.

Stunned owners Brenda and Ray Saltmarsh found the deformed calf when they cut open a distressed cow which had been put down during labour.

What originally had been thought to be twins turned out to be a bull calf with two perfectly formed heads.

Mr and Mrs Saltmarsh, who have a small property at Bagdad, just north of Hobart, said the cow went into labour on schedule last Friday.

But Mrs Saltmarsh said it was clearly stressed.

"She was walking the paddocks. We could see there was something wrong," she said.

"A friend examined her and said it was a very big calf.

"Then another friend examined her and said it was twins."

After a long labour which yielded no result, the farmers reluctantly decided to euthanase the cow the following morning.

The unborn calf, which had been alive the previous night, had already died.

Distressed at losing a valuable cow, the couple cut open the animal to discover why she had died.

"We were all just amazed to see this calf with two heads, perfectly formed," Mrs Saltmarsh said.

"It was rather sickening, but very interesting."

It was not the first such incident in the area, she said.

"A fellow down the road last year had a lamb with eight legs," Mrs Saltmarsh said.

"It was awful."

Veterinary surgeon Dr Andrew Nicholson said a two-headed calf was very uncommon.

"But, like in any species, you can get these accidents of development," he said.

"I have actually delivered a calf with half a dozen legs."

Dr Nicholson said such deformities could be caused by Akabane viruses - usually spread through biting insects - or through the cow ingesting a poisonous plant during pregnancy.

- AAP