Animal welfare standards could have been protected without suspending live cattle exports to Indonesia and a government ban was "irrational", a court has heard.

A group of cattle farmers is suing the Federal Government for $600 million in compensation after live exports to Indonesia were banned by the Gillard administration in June 2011.

The farmers, led by the Northern Territory's Brett Cattle Company, allege the decision to suspend live cattle exports was "irrational, disproportionate and unjustified".

Former agriculture minister Joe Ludwig issued the ban in response to an ABC TV 4 Corners investigation into animal cruelty in Indonesian abattoirs.

In his opening address to the Federal Court in Sydney, the farmers' barrister Noel Hutley SC said animal welfare breaches exposed by the program were "abhorrent" and "appalling".

However, he said the decision to suspend all live cattle exports to Indonesia was unjustified.

"The process miscarried to the point of irrationality, disproportionality and unreasonableness," Mr Hutley said.

"This was a complex issue that did not lend itself to simplistic solutions."

Mr Hutley said the Mr Ludwig was well aware of animal welfare concerns in Indonesian abattoirs, but he didn't give cattle farmers a chance to prepare for a suspension.

"The minister knew there were significant issues with the treatment of cattle in Indonesia, but he also knew it was not universal by any means," he said.

"The industry was never told the guillotine was about to drop."

Minister 'well aware of consequences'

The members of the class action include businesses that provided transport, mustering, feed and agistment services to cattle producers and exporters.

Justice Stephen Rares heard that in 2011, Indonesia accounted for about 80 per cent of Australia's live cattle exports.

The plaintiffs claim Mr Ludwig knew the ban on live exports would result in loss of income and cash flow issues.

Further, Mr Ludwig was aware of improvements at some abattoirs that could ensure animal welfare standards were upheld.

"The minister well knew, we submit, that there were exporters … who were already in a position to provide the assurance," Mr Hutley said.

"He, in effect, shut his eyes because of political pressures."

Animals Australia points finger at farmers' group

Animals Australia continues to defend Mr Ludwig's move to ban live cattle exports and said the former senator had "felt the wrath of cattle producers" and Meat and Livestock Australia (MLA) had "failed" the farmers.

"It was MLA that designed and facilitated the widespread use of the now banned Mark I slaughter box. Had MLA appropriately addressed cruelty in Indonesian abattoirs, this suspension would never have occurred," Animals Australia CEO Glenys Oodgers said.

"The only reason cattle producers can have some sense of confidence that cattle they export to Indonesia are not being brutally treated is because of the action taken by the Gillard government in 2011."

Legal action 'not just about money'

Hamish Brett says his family lost millions due to the 2011 cattle ban. ( ABC News: Dijana Damjanovic )

Hamish Brett, whose family owns Waterloo Station in the Northern Territory, said he hoped the legal action would prevent similar decisions in the future.

"You can't ban something overnight with no industry say in it at all, which is what happened," he said.

"If we get a compensation payout, that's great. It's too late for some people, but we really just want want a change so the Government can't do that to an industry again."

Mr Brett said his family's financial losses ran "into the millions" and he wanted Mr Ludwig held to account for his role in implementing the ban.

The Government is defending the claim, including on behalf of Mr Ludwig.

It is expected to open its case tomorrow.