THE NSW branch of the RSPCA is trying to muster public support for a call to bar feral pig hunts using dogs in the state's forests.

The animal welfare group's campaign comes after the Game Council of NSW called for expressions of interest from "suitable hunters" to take part in a trial using pig dogs to hunt feral pigs.

The trial is slted for the Nundle, Hanging Rock and Tomalla state forests in the New England area, with applications due by 5pm on Tuesday, April 19.

Only experienced, licensed hunters holding a NSW Restricted Game Hunting Licence (or R-Licence) endorsed for dogs can take part in the trial, expected to involve 24 hunters and start on April 30.

While the RSPCA accepts the need to control introduced animals such as feral pigs in certain circumstances, it says the means used should be "justified, effective and humane".

"This is certainly not the case with hunting pigs with dogs," the head of the NSW branch Steve Coleman said in a statement.

The RSPCA is urging the public to contact politicians, including NSW Premier Barry O' Farrell, "to voice their disgust at this barbaric form of recreational hunting".

The NSW Greens have called on the government to ban the practice, which it describes as a "blood sport" on public land.

The Game Council, a government authority that reports to the minister for primary industries, said the RSPCA's claims were driven by an anti-hunting philosophy.

"This is a target program incorporating conservation hunters and has been requested by other government agencies," council chief executive Brian Boyle said in a statement.

"Conservation hunting by the 15,000 licensed hunters contributes to the removal of up to 620,000 game and feral animals from private and public lands in NSW each year."

The RSPCA warned pigs could suffer "considerable" pain in the jaws of the dogs, before being dispatched by a hunter.

"Accredited game hunters (or professional game meat harvesters) have an incentive to ensure that the pig is not mauled or injured, as the carcass would not be acceptable for processing," Mr Coleman said.

"Recreational hunters have no such incentive or requirement for training or applying humane practices."

But Mr Boyle said hunters didn't want the pigs to be mauled because they wanted to consume the meat themselves or sell the carcasses.

"Pig dog hunting training endorsed and provided by Game Council provides for humane animal treatment provisions, and in fact NSW is the only state in Australia providing such hunter education," he said.

The RSPCA also says the practice can be dangerous for the dogs and some may go missing in forests, adding to the state's wild dog problem.