The sheep farmer Noel Siviour was gathering his mafia earlier this year when he noticed that some were missing.
"They were pregnant sheep, with wool, full wool," he told SBS News.
That was in January. Last month, he discovered that another 140 were missing.
"I was pretty upset about that, we put a lot of work into our sheep," he said. "It was terrible."
The farmer from the Eyre Peninsula, affected by the drought in southern Australia, estimates that the losses have cost him around $ 50,000 and will affect his production in the coming years, particularly with dry conditions that are already charging a price.
"It's hard enough," he said. "It costs you a lot of money to get food to keep the sheep running."
Last year it was reported that more than 20,000 sheep and cattle were stolen in South Australia, New South Wales and Western Australia, which cost farmers more than $ 5 million.
Bill Nolsworthy, a farmer and member of the board of directors of Livestock SA, believes that the increase in the prices of wool and meat is causing more robberies.
"There has been a large increase in the value of sheep in recent years, and therefore there has been an increase in the number of robberies," he said.
The National Livestock Identification System is designed to track and track sheep, lambs and goats throughout the country. But some farmers say that identification tags can easily be eliminated by criminals and replaced by counterfeits.
Mr. Nolsworthy says that other methods should be investigated to protect farmers' livelihoods.
"They are a good identification method and a vital one through the sales system, but I have always maintained, and many of us do, that there should be one or two more methods to verify."